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FAQs on Black Ghost Knifefish, Apteronotus (Sternarchus) albifrons 1

Related Articles: New World Knifefishes, GymnarchusNotopterids/Clown KnifefishesElectrogenic Fishes,

Related FAQs: BGK FAQs 2, & FAQs on: BGK ID, BGK Behavior, BGK Compatibility, BGK Selection, BGK Systems, BGK Feeding, BGK Disease, BGK Reproduction, & Knifefishes 1, Knifefishes 2, Knifefish Identification, Knifefish Behavior, Knifefish Compatibility, Knifefish Selection, Knifefish Systems, Knifefish Feeding, Knifefish Disease, Knifefish Reproduction, Electrogenic Fishes, Notopterid Knifefishes (Clowns...),


Re: Got My First BGK      4/27/17
Sorry, its early, haven't had my coffee! The picture is attached here.
<Indeed! Nice tank, if a bit blurry. Assume in real life it looks less blurry. Cheers, Neale.>
Re: Got My First BGK      4/27/17
�� Only gets less blurry *after* I've had my coffee!
Thank you for the advice on the BGK! I have PraziPro here at the house so I'll get that in the tank today! Have a great day!
<Most welcome. Neale.>

Re: Got My First BGK; foods/fdg.      4/30/17
Hello Neale! This is an update with a question I couldn't find on the site. The BGK seems to be doing well. I put the PraziPro in the tank last Wednesday and today I think I may see a little bit of rounding near her pectoral fins.
A friend of mine stopped by a little while ago to see her and give me his opinion (he raises all sorts of predator species). He was very shocked to see how small she is and when I pointed out she was 3 inches, he explained
that the glass of the tank and the water creates a magnifying effect and he didn't think she was that big. Anyway, I told him about her eating most daphnia and Cyclops and not paying a whole lot of attention to the bloodworms and how I'd seen her eating bloodworms at the store. He didn't doubt that she ate the bloodworms, but believes it was a struggle for her at such a small size.
He suggested I start mashing up the bloodworms for her, which I will do immediately, and then he recommended that I hard boil an egg, and feed her small amounts of the yolk (only the yolk) to help support her at this stage in her life. I wanted to know what you thought about his advice.
<Hard boiled egg yolk is old school, and works well. It's a bit messy, as the particles mostly end up in the filter rather than the fish, so best done the day you do a water change. But apart from that, yes, many/most fish will eat egg yolk. Indeed, whenever I'm cooking eggs, I save a little for them! Cheers, Neale.>

Re: Got My First BGK     5/1/17
Thank you!
<No problem.>
Have a wonderful day!
<And you! Neale.>

Re: Got My First BGK       5/10/17
Hi Neale!
As we last e-mailed, I have put getting an Elephant Nose aside for now and I'm focusing on my BGK. I feel so privileged to be able to care and enjoy such an exquisite creature that I may be getting a bit neurotic, but I have a concern, so here goes.
First of all, I had to take the Tetra dither fish out - they seemed to be bullying her away from the food - so they're back in their old tank.
<Understood. There are some very peaceful characins out there, to the point they're "boring" in many community tanks. Hatchetfish for example, and Pencilfish. Both ideal tankmates for juvenile Black Ghosts. As they get
older/bigger, and their predatory instincts become something to consider, there are possible tankmates, though placid catfish are probably the easiest to accommodate, Dianema species for example.>
The Brochis are on back-order so now she is sharing her tank with a 2 inch albino bristle nose Pleco - ONLY! They seem to pretty much ignore each other.
<Correct; the small to medium-sized Loricariids and L-numbers are ideal tankmates for Black Ghosts.>
So, despite the fact that I know my tank was cycled before I got the BGK, I've been doing water tests every few days and the biological filter is working well (never a hint of ammonia or nitrite, and nitrate is staying below 10 ppm as the orange color in the test tube is fairly translucent).
The canister filter and powerhead are keeping the tank clean and the water moving. I feed her Cyclops, daphnia, and now BABY brine shrimp, along with some mashed bloodworms. I defrost and rinse these foods and drop them in the tank at the top of both of her fake hanging plants (remember the blurry picture?) which allows the food to drift down and get caught among the leaves and flowers where she can get to them without the current taking them away to be sucked up by the filter.
<Sounds great!>
I feed her three times a day plus once at night just before I turn out the lights. She looks beautiful! The PraziPro did its job well and she has a nice roundness to her body around her pectoral fins.
<Glad to hear this.>
Her color is pristine black and white and her body and fin are perfect. So what's my problem? Well, every article I read about this species, here and around the internet, says they are nocturnal and don't come out at night; that they stay in their glass tubes or caves during the day. But my fish is not doing that.
<These fish are intelligent, by fish standards anyway, and perhaps more generally. They can and do adapt to daytime activity if there's something in it for them. Peace, subdued lighting, and plenty of food usually does the trick.>
I see her out multiple times of day (mostly in the afternoon). She's in her hanging plants looking for food or swimming between them. She swims through her glass tube and eats what she finds along the way but doesn't
stay in there. I don't see her out at night as the tank is dark, but every morning the food I put in before lights out is gone - nothing left. I know she's sleeping because if I look in the plant on the right side of the tank around 11am, I see her laying in a tangle of the plant's silk leaves. I guess she can hear me in the water,
<Correct; as members of the Ostariophysi, knifefish have excellent hearing and an ability to hear vibrations such as footsteps.>
or maybe she can sense me somehow, because if I say something she'll wake up and drift over to look at me to see if I brought more to eat. I believe she's doing well, but I don't know this species beyond what I've read and
she's not following the script. Do you see anything here that I should be concerned about?
<All sounds good to me! Cheers, Neale.>
Re: Got My First BGK

Thank you!

Need help with Ghost Knife Fish... no reading /RMF       12/12/14
So I just got a Ghost Knife Fish about 6-7 days ago...He's doing well eating and acting fine...I did notice he has to little tiny lumps on his side..almost whitish in color I'd say..I'm assuming this is ich...
<Mmm; not necessarily... are these bumps "in a line"? Bilaterally symmetrical; i.e. on both sides of the fish?>

and from the way a couple of my other fish are acting I think it is..just occasionally rubbing their faces against the rocks...it doesn't seem to be affecting them bad though same with the knife fish...I have a 10 gallon with 3 cloud minnows, a knife fish,
<? This won't work. This fish needs a much larger volume. Let's have you read here:
and the linked files above; particularly the Disease/Health FAQs>
swordtail, gold barb and African dwarf frog...now I want to treat the tank without harming any of them...so would salt be the way to go?
<Nope... PLEASE, follow directions (where you found how to write us), SEARCH, read on WWM ahead of writing>

If so how much do I add and how often? And will the frog be OK?
I don't have any other tanks to move him to....running on a budget..didn't think fish were this involved...stupid me :\ also I have a gravel siphon thing but I can't get it to work right...just keeps getting clogged...so is scooping the gravel out with a net sections at a time and cleaning it OK?
Your help is greatly appreciated-Nicol
<Write back after reading. For now, raise temp., as gone over on WWM for treating FW Ich. Bob Fenner>
re: Need help with Ghost Knife Fish.... still not reading    /RMF over to Neale

So it has to ich because I noticed one of the bumps is gone now
<No; doesn't "have to be"... this symptom could be the result (and its leaving) of several other issues>
...and yes I do plan on getting a much bigger tank for the knife fish in about a month or 2
<If it's alive then>
....so I raised the temperature and its at about 83
<Good... I'd raise it further... to 85-86 F.>
....all the other fish are acting fine and don't see spots on any of them...so would that mean its just a mild case of ich?
<As stated...>
I figured out how to use the siphon thing so i vacuumed the gravel and did a water change...so what should I do from here? Thanks for your help by the way
>Read and welcome. BobF<
Need help with Ghost Knife Fish /Neale        12/12/14

So I just got a Ghost Knife Fish about 6-7 days ago...He's doing well eating and acting fine...I did notice he has to little tiny lumps on his side..almost whitish in color I'd say..I'm assuming this is ich...and from the way a couple of my other fish are acting I think it is..just occasionally rubbing their faces against the rocks...it doesn't seem to be affecting them bad though same with the knife fish...
<Sounds like Whitespot, yes.>
I have a 10 gallon
<Much too small for a Black Ghost.
I hope this is very temporary (a few days...). Minimum 50-55 gallons for a youngster, 75-100 gallons for an adult. Filtration _pro rata_, a big external canister filter probably essential, turnover rate at least 8 times the volume of the tank per hour (so for a 75 gallon tank, you'd have a filter rated at 600 gallons/hour,
which realistically is probably 2 big filters not one. Let me direct you here:
No real mystery to keeping Black Ghost Knifefish, but sadly 90% of them surely die within 12 months of purchase because their owners haven't researched their very specific needs.>
with 3 cloud minnows, a knife fish, swordtail, gold barb and African dwarf frog...now I want to treat the tank without harming any of them...so would salt be the way to go? If so how much do I add and how often? And will the
frog be OK? I don't have any other tanks to move him to....running on a budget..didn't think fish were this involved...stupid me :\ also I have a gravel siphon thing but I can't get it to work right...just keeps getting clogged...so is scooping the gravel out with a net sections at a time and cleaning it OK?
Your help is greatly appreciated-Nicole
<Many Whitespot medications contain copper and/or formalin, and these are usually very toxic to Black Ghost Knifefish. Your best bet is the old salt/heat method. Used correctly and for just 10-14 days shouldn't stress any other fish or plants. Read here: http://www.wetwebmedia.com/fwsubwebindex/SaltUseFWArtNeale.htm
And also here: http://www.wetwebmedia.com/fwsubwebindex/bgkdis.htm
With Black Ghosts, prevention is infinitely better than cure because many/most medications are lethal to them. Robust filtration, a large aquarium, and very high oxygen levels are the three keys to success.
Feeding can be tricky, but not impossible with modern frozen foods.>
It's rarely necessary to deep clean gravel. Get a stick of wood, bamboo for example, or even a clean chopstick (the sort given away with sushi boxes are ideal). Before you do a water change, run the stick through the gravel, mussing the gravel a bit, but ignoring the areas within 3 inches of any rooted plants. It's also a good idea to clean underneath rocks and other
ornaments too, so if you can, move or remove them as well. Once you've done this you'll find the water will be a bit cloudy because all the muck as come out of the gravel into the water. Now's the time to do your water change! You can use the sucking end of the hosepipe to slurp up as much debris as possible, but watch out for small fish. If all else fails, and you've got small frogs, shrimps and fish that might get scared or sucked up, then don't bother cleaning the gravel directly. A good tip: design the tank so the gravel slopes forwards, i.e., the gravel layer is deep at the back of the tank, shallow at the front. All else being equal, dirt will tend to roll down to the front, where you can suck it up with the siphon.
Even a turkey baster is useful for occasional "spot cleans" when you don't want to disturb the fish with a water change. Cheers, Neale.>
Re: Need help with Ghost Knife Fish /RMF    12/14/14

OK and how long should I leave it like that?
<A couple weeks. READ on WWM re Ich>
And should I be cleaning the gravel and doing water changes everyday along with this?
re: Need help with Ghost Knife Fish /Neale     12/14/14

OK...also got a couple questions regarding the ghost fish...how fast will he grow cause he's really small right now?
<Impossible to state and varies with age. But relatively slowly. Half an inch per month would be about right. A lot depends on water quality, temperature and the quality of their diet. They can reach full length within a couple of years, but are very long-lived fish, with reports of 20+ year old specimens in zoos.>
And what kind of foods should I be feeding him for a good diet?
<A good question. In the wild they are "vermivores", meaning they feed extensively on worms and worm-like animals (insect larvae for example). You can buy frozen versions of these easily: bloodworms, glassworms, mosquito larvae, etc. However, ideally you'd get them trained to take a good quality flake or pellet food. Hikari Pellets for example, or New Life Spectrum
flakes. Premium stuff. These prepared foods are vitamin-rich, and if used correctly, make an excellent staple. Bloodworms, while apparently delicious, are vitamin-poor, and there's some concern that they're raised in dirty water laden with heavy metals and/or other toxins. Many fishkeepers have stopped using them because of this. Brine shrimp, whether live or frozen, are worthwhile as an excellent source of fibre, but unless "enriched" (as some frozen Brine shrimps are) they aren't especially nutritious. Black Ghosts have tiny mouths, and even the adults -- which can 50 cm/20 inches long -- only just about manage earthworms. But as I say, earthworms are excellent food and probably the best live food for them.
Don't ever try feeder fish though. Too risky, no benefits, and not a natural part of their diet anyway. Overall, a little but often works well with BGKs. 2-3 meals a day for youngsters. A gently rounded belly is good, but you don't want one that looks like it's swallowed a golf ball!>
He's just been eating freeze dried blood worms at the moment but I read that just a diet of these for them is bad..true? I've tried feeding him some flakes and shrimp wafers by he didn't like neither
<Persist, read, understand. Freeze-dried bloodworms are just about the least useful food source, and long term, won't work. They may supply some calories, but they're vitamin-poor, which means you'll end up with health problems eventually. Since BGKs are so difficult to treat, prevention of sickness is your game plan here. Cheers, Neale.>
Re: Need help with Ghost Knife Fish.... not a reader
OK and how do I get him to eat the other foods? Because I've tried feeding him some flakes he didn't like those or the shrimp wafers...he just seems to like bloodworms :\
<Kids like candy too, but their moms don't raise healthy kids on a diet of M&Ms! There are many ways to get fish to eat novel foods. Patience is always central. But offering a variety of options to see what's taken, starving the fish for a few days if an appetite is needed to sample something different, and not giving up too quickly are the essentials. When you buy a Black Ghost Knifefish you should be aware that they aren't easy to feed. What live foods do you have available? Brine shrimps? Daphnia? Small earthworms? What fresh or frozen foods have you tried? Gamma irradiated if possible, especially if Tubifex worms are used. What more to say... these fish will eat all sorts of different things, as discussed earlier, but if only given bloodworms, they won't do well. Would direct you to this page:
Much said about Apteronotus there, and reading, reflecting on such will help you and your pet. Cheers, Neale.>
re: Need help with Ghost Knife Fish
So I basically need to stop feeding him to the point where he's so hungry he eats something else?
<Pretty much. Easiest done when fish are young because they learn faster.>
Feel so mean doing that cause he's used to being good.. But if I have to I will...and I have no life foods...just goldfish flakes, tropical fish flakes, Betta food, shrimp wafers (they cloud up the water horribly), and bloodworms....I get paid Tuesday so I can get him whatever he should have then..he's also taught to come to the top of the tank to feed
<Look into traditional frozen foods. Very useful and cost effective.
Kitchen scraps are a good way to stretch your budget too. If you eat white fish or seafood, both make good additions to the diet, even staples if you select appropriately:
Cheers, Neale.>

BGK care and compatibility questions     3/13/13
Hi Crew.  Thanks for all you do for the hobby.
<A pleasure to aid (educate, inspire) others; as you know>
I've been keeping some fresh and mostly saltwater (only fresh these days) for 25 years, and I've always wanted a black ghost knife--a neighbor had a very tame one when I was quite young, and I loved it.  But I never felt I had an appropriate tank for one; I've never had a large enough freshwater tank before, and never a tank with appropriate tankmates.  Now I think I might.  I've read through the FAQ's on BGK's, and found some answers, but not everything I need to know.
First, because I know everything depends on it, let me tell you about the tank: it's a 150G (long, not high--I have one of those, too!), using a Fluval FX5 for primary filtration, assisted by a HOT magnum just for water polishing and carbon, and 4x96w 6500K power compacts for light.   The tank is pretty heavily planted, mostly several varieties of swords and Anubias, and some java fern, accented with pieces of driftwood.  Water parameters are 0 ammonia, 0 nitrite, nitrates 15-20, ph is around 6.4, and temp is 80 F.  The tank was converted back to fresh water 2 1/2 years ago.  I intended it to be a discus tank, but my first attempt at discus keeping was not successful, and I gave the surviving discus to someone who could care for them properly.  (The discus weren't eating well--they seemed unable to "catch" the food in the tank.  I'm now given to understand the problem was probably too much current from the FX5.)  The tank's current occupants were mostly selected with discus' warm, soft water conditions in mind: a large school of cardinal tetras, a pearl gourami, Bristlenose Plecos (which have been mating!), 8 Otocinclus cats, and four pairs of blue rams.  I also added three clown loaches about a year ago to take care of a huge snail problem that came in with the plants.  They seem to be doing well, the largest has grown to about 5", with the other two more like 3".  Most recently, I added 6 angelfish--a consolation for not keeping discus. 
Tonight, it occurred to me that the time might be right for a black ghost, or perhaps two.  I know they would eat the tetras when they get big enough, but the tetras have started to die off, apparently from old age--their tails get more and more hooked downwards, their colors begin to dim, and eventually, over the course of weeks, they get thin and die.  At first, I thought it was a disease, but now I don't think so.  They're over two years old, and I think they've just reached the end of their lifespan.  I don't plan to replace them--at least not with more small tetras.  Perhaps some Von Rio's?
<A good choice here... or (for me) Bleeding Hearts, other Hyphessobrycons>
So my first question is compatibility.  Do you see anything that would be a real problem?
<Mmm, no. Just care to make sure the Knife is getting food amongst so many competing fishes, in such a large setting>
 I was somewhat concerned about the loaches and the rams, but I've never seen the loaches act aggressively towards each other or anyone else, and the rams mostly keep to themselves, really.  I thought that with the high plant density, the BGK would be able to find a nice quiet nook in which to be happy.
 My second question concerns keeping BGK's together.  I know that they get big, and are generally a one-per-tank fish, but a couple of times in the FAQ's crew members commented that two might be kept together if the tank was large enough--but no one ever said how large is large enough!  What about a 150?  If I started with two 4" BGK's introduced at the same time, does that stand a reasonable chance of working?
<Two would make for a more interesting, interactive display. I give you good odds that a couple would learn to get along in this setting>
Thanks in advance for your help.
<Welcome. Bob Fenner>

BGK suddenly shy  11/12/07
Hello Crew, I've had a BGK for 8 months now. He lives in a 55 gallon tank with 2 clown loaches, 3 discus, 2 rams, and a golden nugget Plec, with loads and loads of plants. I do weekly water changes, and water conditions are almost perfect. ammonia 0, nitrite 0, nitrate trace. People always comment on how crystal clear my water looks. He's been very healthy and happy, and growing slowly. There are several hiding places for him but he has taken up home with the 2 clown loaches in a black tube. <Predictably> The three of them swim about looking for food during the day as well as when the lights go out. As soon as I drop food in, those three are the first on the scene playing with each other and eating as fast as they can, its so cute to watch. <Ditto> But in the last 3 weeks or so, the BGK has stopped coming out. He just stays in the tube wiggling about. At feeding time only the loaches come out. I'm very careful with over feeding so the food I put in is always all gone within ten minutes. So I'm 99.9% sure the BGK hasn't eaten in 3 weeks!! <Mmm, is eating something, assuredly... Perhaps you have other food... live worms and such, living in the gravel at this point> Is it normal for these fish to suddenly change their behavior? <Does happen> Today, I fed my discus live bloodworm as a treat, one worm landed in front of the hiding tube and the BGK stuck his head out ate it and went back in. My question is, how could a friendly full of life BGK suddenly become a scaredy cat? there has been no changes, no new tank mates, no change in feeding schedules. My tank is always in view, and he never comes out, day or night. Can there be a chance of illness with him? What can I do? thanking you in advanced Freddie <If I had to guess... I'd say that the most likely possibility is that your Discus are getting larger, perhaps showing a bit of aggression toward this Apteronotid... Do try to spend a bit more time in front of the tank to observe... If two do pair off, there may be trouble for all the other fishes here. I might try some cultured black worms (tubificids) to urge this Knife's return to feeding. Bob Fenner>

Black Ghost Knifefish and Ich 10/24/07
<Hi Jillian, Pufferpunk here> I am at a loss as to how to treat my two BGK fish. They live together in a large tank along with two Raphael catfish and an Oto whom they surprisingly do not bother. Recently I noticed a few small white spot (suspecting ich) on one of the BGK, and am wondering what is the best course of action for treatment. Firstly, should I isolate the infected fish or treat the tank as a whole since all fish have now been exposed? <I would treat the whole tank with heat & salt.> Secondly, what it the highest temperature that BKNs will tolerate, as my usual treatment for ich is to up the temperature to 82-84 F and add 2Tbs of salt per 10g of aquarium water? <MT BGK lives in a discus tank with a normal temperature of 86. Since these are soft water fish, I'd start with 1 tbsp salt/10g.> This leads me to my third question, is it better to treat the BGK with this salt treatment or to use a product like RidIch at 1/2 strength? <I wouldn't use meds on scale less fish. Before starting treatment you should do at least a 50% water change and vacuuming of your tank. I also suggest doing 50% water changes every other day of treatment, (again vacuuming the substrate) to reduce the number of parasites in the water. I do not like to use medication with scale less fish, except in cases of heavy infestation. Melafix is helpful to treat any damage done to the puffers skin from the parasite. If you run into any secondary bacterial problems, Pimafix may also be used. By the 2nd day of treatment, you can raise the salt to1 tablespoon per 5 gallons of aquarium water (remember you already have 1 tbsp/10g in there, so adjust for that), while gradually raising the temperature to 86 degrees F. Continue with this for a period of one month, adding back 1 tablespoon of salt for every 5 gallons of aquarium water that you remove during water changes. One thing to remember with high temperatures is that there is less dissolved oxygen available in warm water than there is in water at cooler temperatures, therefore it is recommended to run an additional airstone to oxygenate the water.> I am a little attached to these fish and would like to see them make it through this. Thank you in advance for the advise. <It sounds like you have caught the disease early & your fish should be fine. ~PP> -Jillian Scharfstein 

Black ghost knives... hlth., reading   10/23/07 I have 3 black ghost knives, 2 of which have dangling "worm-like" appendage from the throat. It's usually about 1.2-2 inches long. I don't know what it is or how to treat it! Please help. Thank you. Regards, Allison <... could be a parasite... Worm... I'd treat with Prazi.... Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwwormdisfaqs.htm and the linked files above. Bob Fenner>

Black Ghost Knife / Filter Contamination   9/4/07 I'm an intermediate fish keeper, have been doing it for a few years (beginner still, I suppose). Started with 5 gallon, then 20, and now a 72 bow. It has a wet/dry filter a temperature of about 81 degrees, and as far as water quality, I haven't read ammonia, nitrite, OR nitrate in the past 6 months, and a PH hovering between 7.8 - 8.0. It's fairly established, maybe 9 months old, tropical community. <All sounds very promising.> I recently purchased 2 Black Ghost Knives (BGK) fish from my LFS, and added them to tank (yes, I know quarantine should be done, but college has me on a nickel-dime style budget). <Ah yes, I remember those college days well!> The fish (perhaps 4 inches) seemed very content, swam happily, found hiding amongst rocks and water lilies, and came out at night to feed. None of the other fish were aggressive towards the knife (with possible exception of Zebra Danios, but they stay topside, and vice-versa for BGK). <OK.> After two days, I had the lovely sight of coming home to one of my BGK's stuck to the strainer on the overflow... lived through that, but died soon thereafter (my fault, water flow rate has been adjusted accordingly, they won't get stuck now). <This doesn't sound like cause and effect to me. Apteronotus live in big river systems, in quite deep water. It seems unlikely to me that a filter could create too much current for this sort of fish. Usually, when someone finds a fish stuck in the filter, the fish died, or was weakened, and the filter merely dragged the body towards itself. A healthy fish should have no problem avoiding a filter.> That death I can understand. <I can't.> Five days later, I wake up to see my other BGK lying on the sand (dead, of course). <I see. Now this sounds as if you have two cases of Apteronotus death, with the filter implicated just the once. This reinforces my opinion that the filter had nothing to do with death #1.> No visible signs of biting or otherwise aggression related harm. I'm totally stumped. My question to you is this: Could the slightly high pH of my tank have slowly killed him, or could it have been something else? I'd like to get another, but I want to be sure of the problem on my end (if there is one) so I can fix it, thus avoiding an unnecessary death of a beautiful fish. <Apteronotus are not easy fish. They are incredibly sensitive to water quality. In terms of water chemistry, they aren't especially fussy (Fishbase reports pH from 6-8, 5-19 dH) and comparable to most other South American tropical fish. So your pH/hardness issue is unlikely to be the cause of death. The exception here would be if the water chemistry *varies* a lot. But provided it was constant, even a relatively high pH shouldn't be a problem. (This is true for most freshwater fish in fact: steady water chemistry is more important than clumsily going after some mythical "optimal" values.) So, here's what I'd be investigating. Firstly, is your water chemistry very different to that in the store? For example, do you soften or acidify the water, or add peat to the filter. Secondly, what scale/frequency of water changes do you do? Weekly 50% water changes should prevent the inevitable background pH change in all aquaria from becoming significant. But if you do small water changes, say, 20% every couple of weeks, then the pH could drop in the aquarium over the two weeks, and then rapidly go up when you add new water. This would be bad. Thirdly, I'd be testing for nitrite across the day, maybe three or four times. Sometimes, tanks develop nitrite problems shortly after feeding, but seem to have zero nitrites at other times. Spikes in nitrite concentration would be lethal to something as sensitive as Apteronotus. Fourthly, are you adding anything to the water (other than dechlorinator, naturally)? Some benighted folks go round adding stuff like salt and anti-stress medications on a weekly basis, and while hardy tropical fish shake off these misguided annoyances, Apteronotus will not. While we're on the topic of dechlorinator, make sure yours removes chloramine, if you live in an area where chloramine is used. Finally, did you add any medication? Apteronotus are intolerant of many commercial brands of things like anti-whitespot medication. If you used these in the recent past, adding some carbon to the filter for a few weeks might be a good idea.> Any help is greatly appreciated! <Done my best!> -Brandon <Cheers, Neale> (thought of another question, couldn't get a straight answer elsewhere) <OK.> In my 72 gallon tank w/ overflow and wet/dry filter, I use a filter pad that claims to be re-usable with cleaning. It's instructions for cleaning are to soak 1 part bleach w/ 10 parts water overnight, then rinse, then soak in plain water overnight again. Is this adequate to rid the bleach? I've had some strange occurrences lately (mollies dying, no reason) given my water quality is good (0, 0, 0, pH 7.8 - 8.0, 81 deg.), and am starting to think it might be bleach contamination. Just curious on any insight or special tricks to know when the bleach is chemically gone, not just sensibly. Thanks! -Brandon <Agreed, this sounds like a dumb idea, so not sure why the manufacturer are recommending it. If you need to wash something, hot water should work fine. Sometimes I soak things in brine if these need a deep clean (e.g., it's an ornament I left out in yard over winter and its covered in mud and slime). Once you rinse the thing off, any traces of salt will be harmless. It is entirely possible traces of bleach have irritated your fish, leading to death. So, stop doing this. Clean the filter the old fashioned way (in buckets of aquarium water) and then replace sponges when they are so clogged they can't be cleaned any more. NM>
Re: Black Ghost Knife / Filter Contamination 9/5/07
Thanks for all the info on the BGK! <You're welcome.> I do bi-weekly changes of about 20%, so I would assume from your reply I should be doing something more towards 40% on a weekly basis? <More like 50% for something as sensitive (and big) as Knifefish.> (Sounds like a lot of water, closing in on 30 gallons). <Them's are the breaks.> I use a product called "Prime" to treat incoming water, as well as some time (chlorine has a slight evaporative property if I recall correctly). <Absolutely DO NOT rely on chlorine evaporating. Use the full dose as stated on the carton, and stir well. Also, if your local water board uses chloramine, that won't evaporate.> I will begin more thorough logging of pH and nitrite for a two month period or so, to see average variance. <Very good.> In summary, I suppose, a 30-40 (even 50) % water change weekly would maintain a stable pH for my tank, and not be detrimental to the fish at the same time (in terms of massive quantities of water coming in and out on a regular basis)? <Assuming you do the water changes regularly, the dilution effect will mean the pH/hardness in the aquarium will be approximately equal to your tap water supply. A week isn't long enough for the pH to drop much. The main thing is to check temperature of the new water matches the old, so that there isn't a huge temperature drop when you add the new water.> It probably was the pH, because now that I think about it, I changed 13 gallons of water the day before he died... <Sounds like clutching at straws. What makes you think the pH changed? What's the pH of the tap water, and what's the pH in the aquarium? Water changes where the pH/hardness are the same in the old water and new water DON'T DO HARM. That's old school fishkeeping. Nowadays we've learned new water is best, and some people even do 90% changes per day!> I'm so sorry for all of the questions, but I care for my fish more than most people, and I want to do everything I can to ensure their good health. <Very good.> In regards to the filter pads, the problem with just washing with aquarium water is that it won't clean it well enough. <Get over it. Biological filter pads don't need to be deep cleaned. All you need is to rinse off the worst of the silt. So, don't EVER wash biological filter pads in anything other than aquarium water. For the mechanical filter pads, deep clean with hot water, or else replace with new ones. Now, this said, if your filter is getting so dirty the pads are irretrievable, then you are either cleaning the filter too rarely OR you have too small a filter for your aquarium. Under normal, correct use a filter should only need cleaning at most once a month, and even then the sponges should be easy to clean in buckets of water.> I set mine up as two-stage filtering, first is a large plastic pad (kind of like a scouring pad) to catch large debris (and the occasional small fish). <????> The second one (which is bleach cleaned) is a 100 micron pad, looking more or less like felt. This makes for remarkably clear water, but the downfall is that they needeth be changed every three days at best. <The second filter is the biological filter. You absolutely should not be cleaning this in anything other than aquarium water. Your filter sounds basically inadequate, and almost certainly not removing nitrogenous waste quickly enough. And that's why your Apteronotus died. Until you create and mature a more reliable filter system, don't buy any more fish> At $20 for every 9 of these, it can add up. Bleach cleans them wonderfully, but I suppose if it's hurting my fish I shall find another way. <Indeed you MUST. Please read the articles here at WWM on filtration. I'm not convinced you understand the theory and practise yet. You shouldn't need to replace filter media more than once a year, and I don't replace biological media for periods of 5+ years at a time. If you're finding your filter media completely clogged up and useless before then, you have a problem.> I much appreciate your help, and in a few weeks, maybe a month, I'll take another shot at a BGK, and I will be sure to let you know of the happenings of him/her). <No! It will take 6 weeks, minimum to mature a biological filter to the point where it is stable. Since Apteronotus don't do well in "new" aquaria, I'd not expect to keep one safely for at least another month or two after that. You need to review your filtering system. Minimum, it should provide 6 times the volume of the tank in turnover per hour (i.e., for a 55 gallon tank, the filter should be rated at around 330 gallons per hour). The filter media should stay so clean that you only need to rinse them off every 1-2 months. If you don't have these things, you don't have a system that can contain Apteronotus albifrons. Buy another one... and it'll die.> -Brandon <Good luck, Neale>
Re: Black Ghost Knife / Filter Contamination 09/05/07
Again, thank you in kind for the help! <You're welcome.> My tap water has a pH of about 8.0. <Admittedly not ideal for this species. But not toxic, either.> Prime removes chorine and chloramine. I mix water with powerhead in large plastic tub with its own heater and digital thermometer to make sure it's within 0.2 degrees of tank. I can deal with lots of water usage, lives are at stake here ;-). <It's not so much that, as the fact doing a 50% water change compared with a 20% one really isn't that much work by the time you have the buckets and hose pipes. So you may as well do a big water change and improve water quality while inhibiting background chemistry changes.> Best thought about pH being cause of death (more likely TDS or dH) is that I had gotten behind on water changes (school starting, personal issues, etc..) had been maybe a month. I can imagine pH could have dropped enough to cause a shock to a Knife when higher pH water was added. <Indeed. That's why we need pH test kits.> The filter pad in question is not the bio-filter. It's a mechanical pre-filter for a 75 gallon wet dry filter with a 700gph pump (which probably puts out more like 500 with head and friction loss) = ~ 6-7 times turn over rate in tank (on full flow - have a diverter to pump part of flow right back in sump if flow need be slowed down - doesn't restrict flow from pump, but does to tank). Will probably switch back to a more conventional pre-filter (i.e. floss pads or similar) to alleviate consistent changing of micron pad (which was every 3 days). These are easily replaced, so no need to clean, right? Biggest thing that clogs micron pad is plant matter (tank is planted, and a Geophagus brasiliensis enjoys digging them up/ chewing off bits of plants). Tank is established (in my mind, at least) being almost a year old with no traces of ammonia, nitrite, or nitrate in the past 6 months. The bio-balls never clog, but the mechanical pre-filters do in time, from said plant debris. I think you simply misunderstood my filter type, perhaps thinking I had a large power filter or something similar. The wet/dry is marvelously efficient for freshwater from my experience. <Agreed, these filters can be very good. If the pre-filter is clogging, then just use something cheap instead of the expensive units supplied with the filter. Ordinary filter wool should work, no? Alternatively, clean the pre-filters much more often, every couple of days if required, just rinsing them under the tap.> I also enjoy very much reading your site, I spend a good hour a day, 5 days a week on here trying to learn more. <Glad you enjoy.> Anyways, I will try the larger volume water changes and see how it works with current fish, and continue to test pH (and possibly carbonate hardness and TDS...read up on those, apparently too many TDS can cause a difficulty for fish's cells absorbing the diffused oxygen in the water, and as for the hardness (if I read correctly) if the hardness is maintained, the pH will be less likely to change, hence providing a more stable water chemistry, which is the overall goal here). <In theory, yes, TDS (total dissolved solids) is related to osmoregulation. BUT, once a fish is acclimated to a certain TDS level, sudden changes, even towards "better" levels, can be bad. So it's better to have a fish acclimated to the "wrong" water chemistry but maintaining very stable water chemistry and quality, than trying to force your tank to the "right" water chemistry while bouncing around pH/hardness in the process and skimping on water changes because of the expense. In other words, don't fixate on the value so much as the stability and quality.> I am greatly in debt to your help, and am hoping to learn how to maintain a VERY stable water condition, because I am very bent on being a successful BGK keeper (saw a nice 75 gallon tank the other day, would make nice home for a few years for him... till he got bigger, that is). <There's no secret to stable water conditions: big tank, under-stocking, good filtration, and above all, large and regular water changes. Likewise, the causes of unstable conditions are well known: too many fish, lots of organic decay (plants, general muck), clumsy manipulation of water chemistry through use of peat or buffers, and infrequent water changes. So, do the first list of things and avoid the second list, and you're laughing.> Hopefully I can apply everything I've learned from you and this website to make it happen. Thank you more time! -Brandon <Glad we could help. Good luck, Neale>

Black ghost knife fish I have a BGK fish and yesterday noticed three splits in the fin under his body, today there must be about thirty of these splits, could you help me in finding out what this is and what I can do. Yesterday I bought a new African Knifefish and wondered if this may be the cause, I'm not sure because the splits were already there  before I added the new fish. Thank you Anita <These two may well be fighting... during the night probably... I would separate them... the Black Ghost will heal on its own otherwise. Bob Fenner>

Black Ghost Knife Won't Eat I bought a black ghost knife  week back and gave it a small place to hide. Since then it has been hiding inside and very few times, twice in fact, it came out in the night. Apart from this it does not eat anything. I feed it in the night to discover that the food is still floating in the morning. Will it take time to get set in the tank or is it sick? There were small molly fry in it which  I bred and it has not touched them. Is there anything wrong with it ? Is it a strong or a delicate fish? I do water changes once a week. Pls advice <Your black ghost knife fish is indeed a nocturnal fish. Try small live invertebrates live worms or shrimp. After awhile you may get him to try frozen foods and then maybe pellet foods. If you can get him over to prepared foods then keeping him will become much easier. If you can't then live and or frozen foods may make him difficult to keep.-Chuck>

FW algae and Apteronotus skin Hi, In my 29 gallon tank there are re-brownish specs on everything. My water parameters are fine and I do weekly water changes and cleaning. what do you think it is? <Almost undoubtedly algal colonies... take a read on WWM re> Also I have a Black Ghost Knife for about 10 months now and since November he has shown a weird green/brown gel-like coating over him. I thought it was ick but wouldn't have died by now if that was the case. Do you know what it is and how to treat it? thanks. <This is probably the animals skin itself... and your good vision. The species is "quite slimy" in good health. Bob Fenner>

FW algae and Apteronotus skin, II Bob, thank you for the response I just wanted to add that my knifefish's slime is a little whitish-gray when the aquarium light is on, does that make a difference? <Actually, yes... as stated, you have excellent vision, observation> I mean when I go to the pet shop all the ones are pure jet black. Jahner <These are more stressed... Bob Fenner>

Black ghost knife problems? Hi Robert, I'm a bit worried about my new BGK (my new favourite fish!). I am currently setting up a new tank after becoming addicted to my boyfriend's set up! New tank is 80 litres, planted and has a fine gravel substrate. It is currently stocked with 2 Pearl Gourami, 2 Angels, 3 Tiger Danios, 2 Corydoras sterbai and a small (2.5 inch) BGK. <This IS small!> Tank is two weeks into its first cycle. <Yikes... Knifefishes don't "like" new systems... Hard on them to go through their initial chemical, biological changes> The BGK has been in for 3 days and while it seemed happy in the first two (hiding amongst plants) but I have come home from work today and it doesn't seem right. It is sort of hovering around the bottom of the tank, moving around almost like a drunk person. It kind of wobbles around a bit, then rests and then wobbles around again. It has plants to hide in, as mentioned, and also a piece of driftwood to go under but it doesn't seem interested in this. <Mmm, well, this is pretty standard behavior for the species... but... do you have another, older system you can/could move it to?> At the LFS it was happy hiding amongst Java Moss and seemed unconcerned with the lit tank (I'd watched it there for a couple of days and it seemed very strong and healthy). There are really no other signs/symptoms except this apparent listlessness and my gut instinct (and it appears to be easily caught in the relatively light current and moved along which wasn't happening yesterday). I checked the water parameters and everything was fine - Ph 7.0, temp 26C. Nitrite was very slightly elevated but not of note (I have added Amtrite down to fix this.) <Mmm, only temporarily and at a "cost"... as stated, Apteronotus don't like "going" through cycles> Is it just acclimatizing or do I have a problem?? <Perhaps both> Please help, I was really impressed with what I've seen on the site and decided you're the man to ask! Thanks. Alia <Best to move the specimen to an established, similarly peaceful setting, second best to be very careful of not feeding much, urging your completion of biological filtration (Please see here: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm.  Bob Fenner>

BGK   1/27/06 Hi there, I have a 35-ish gallon tank, to be moved up to a larger one soon. I was planning on keeping some smaller knife fish in it for now, however all my LFS's only carry black ghosts. I am aware that these grow to ~20 inches, am I right? <Rarely more than about eight inches overall in captivity> Are there any other more suitable knifes for my tank? <... would have to know more re> It is well planted, with driftwood, etc., (lots of hidey-holes) and I have several medium sized (~3 inches) Gouramis, along with some small, 2 inch clown loaches, a whiptail cat, Pleco, and CAE, <This last may become trouble in time> as well as some cichlids. <... sounds pretty crowded... S.A. Knifefishes are not ready "fighters" for food, space> I am planning also on introducing some Cory cats, African butterfly fish, a dojo (weather) loach, and possibly (but not likely) an elephant nose. <Then skip on the knife/knives> I realize the elephant nose should be alone in a tank of my size, but could I keep more than one BGK (small, ~3-5 inches)? How fast do these guys grow? Will there be any conflict between them, or will the elephant nose and BGK's electric field thingies bother each other? <Yes> As well, what about their feeding habits? Will their nocturnal behaviour keep one or the other from getting food? I also have some medium sized angels, but I don't think they'll be too much of a problem...if you guys have any better suggestions to my choice of fish, please tell me. My LFS's all tell me that everything will work out fine, but then again, they would tell me Neons are compatible with knife fish if it meant I would buy them. I do kind of have myself set on knife fish, because of their method of movement, but please tell me if you do not think I have adequate housing for these fish. I realize I am asking quite a bit right now, so I thank you in advance for anything you can do for me -Eddy <You need more tanks Eddy... Bob Fenner>

Re: BGK   1/30/06 Thank you for the quick response. I will be keeping my CAE in a different tank, it is getting pretty aggressive... I think I'll skip on the knives till I get at least a 50 or 60 gallon, will this do for the knives? I'll stick with the Corys and butterfly fish for now. Thanks, Eddy <Welcome my young friend... Have you considered working part time at a local fish store... or volunteering (if one's nearby) at a public aquarium? Bob Fenner> Knifefish Fin Problem   1/10/06 Hello, I've had my Black Ghost Knifefish and Blue Gourami for well over a  year now. My water parameters are all normal. The Temp. is 79 degrees. They are  in a 29 gallon soon to be in a 55. My problem is that I have just noticed that a   few of his fins are torn right near his tail. Is this a result of fighting? <Possibly> Will  it heal on it's own? <Should... with the move to larger quarters, good care> Will he be all right or will he need any kind of medical  attention? Thank You <Be careful with treatments around the Apteronotid Knife... often more toxic, hazardous than worthwhile. Good clean water, decent nutrition should cure all here. Bob Fenner>

Black Ghost Knifefish, Quarantine - 10/17/2005 Greetings and salutations! I would like some advice on caring for a Black Ghost Knife. I brought home a healthy specimen at around noon, and put him in a 10 gallon quarantine. <Ah, good. Quarantine is essential with new stock.> He was a beautiful deep black with off-white markings, roughly 4 inches. It's now 2 AM and the entire front part of his body has faded to a silvery color. <Go to sleep! Actually, he could just be fading to more nocturnal colors.... though I cannot recall having seen them change to lighter colors at night - but many fish do.> It's as if his black is fading completely away! My QT water parameters: Nitrite/Ammonia-0ppm, Nitrate-10ppm, temp-78F, slightly hard water, pH 7.2. <What pH was he in at the store? He could be suffering from a bit of a shock from change in pH and hardness.... They hail from waters of low-ish pH and low-ish hardness, so this may be part of the issue. At this point, however, I would not change what you have - a steady pH is FAR more essential than a "perfect" pH.> The tank is bare but for 2 PVC pipes. <Large enough for him to enter and hide in?> The tank is in a private room, and the light is off. The fish is swimming "normally" (like an excitable drunk). Fed some frozen brine shrimp earlier, but he seemed to be spitting them out. <He may not eat for a day or so.... but likely you will need to start him on live foods. I could be mistaken, but I believe these animals are only wild-caught and not at all bred in captivity.> I read that these fish are very sensitive and their rich black color may fade due to stress, but I was wondering how common it is for this fish to fade so drastically in this short period of time!!! <Mm, 14 hours isn't really a short period of time.... a fish turning pale at night can do so in minutes. 14 hours is more than plenty of time for the fish to get stressed, as well.> I will keep a sharp eye (I can't sleep the way it is). Should I add a bit of salt? <No.> Stress-zyme? <No.> Is there possibly a metal in the water that Aqua-safe is not removing? <Not likely that this is what's harming the animal, if anything. I would suspect a poor reaction to a sudden change in pH above all else.> I always appreciate your help, thank you in advance. ~M <All the best, -Sabrina>

Black Ghost Knife Compatibility, Disease - 10/12/05 Hi - <Hello.> I have a black ghost knife that was bought recently - about 5 inches long. He's in a community tank and unfortunately we forgot about the nippiness (is that a word??) of our Serpae tetras. <Uh-oh.... Err, *I* say 'uh-oh', but Bob (whom I'm visiting currently in HI) says there really isn't a compatibility issue here. I, personally, would be a little nervous about these two species together.> They have bitten off the end of his tail!! RIGHT TO THE 2ND BAR!!! <I do agree with Bob here that the Serpaes may not have been the sole contributor here - please check your water quality. Maintain ammonia and nitrite at ZERO, nitrate less than 20ppm, with water changes.> I treated the water with this thing called MelaFix for any bacterial infection that it might get( I'm in Australia - hopefully you know what that product is!!) <I do.... and though MelaFix (extract of the Melaleuca tree, or "tea tree") does seem to have some mild antibiotic properties, I would not rely on it alone as a medication for anything severe.... furthermore, I have seen evidence in my own fishes that it may be a little (or a lot) irritating to the fish.> He seems OK but I'm worried that he won't survive without the tip of his tail. Is there any thing else I can do to help him out?? <Maintain optimal water quality, and (though Bob and I disagree on the Serpaes!) keep him separate from any fishes that might bite or nip at his wounds until he's healed. The end of the tail might not grow back in its entirety, as well.> Also we recently moved house (about 3 weeks ago) and obviously had to transport tank and contents. It's a 4 ft tank (180litres) so we took about 1/2 the water with us and didn't clean filters out etc the ph is 7, the nitrites are 0.1 and the ammonia 1.2. to me this is high as it is normally 0. <Dangerously so.> Is there any thing I can do to lower ammonia levels. I haven't done a water change since we moved. <Water changes alone will fix this.... and it is urgent that you do.> Thanks for your help... Tam <Any time, Tam. Wishing you well, -Sabrina>

Black ghost knife fish 10/12/05 Hello guys just thought of saying thank you for all your useful info. <And thank you very kindly for these words.... It is great to hear/read this, some times.> I had a 55 gallon fresh water planted tank that was running for about 2 and half years. Fish in the tank: 1. a black fin shark (5") <Gets very, very, VERY large with time....> 2. a black ghost knife fish (8") 3. 2 adult angels, a marble and a golden (3" in diameter) 4. a rope fish (8") 5. a Pleco (5") 6. a stripe Raphael cat (4") 7. 3 tiger barbs (2 ½") 8. 2 ruby cichlid (2") <A touch overstocked for my tastes! Just be sure to keep up with water quality....> It wasn't until two months ago that I started having trouble. I acquired the 3 tiger barbs from the fish store when I normally go. Some lady came in and left two containers full of huge fish, between them was the three tiger barbs that I took. I introduced them to my tank without using a quarantine tank the way I should have. <Ohhhh, no.> One of the barbs became really fat. After reading a little I thought it could have been pregnant. About three weeks later I noticed that it had cloudy eyes. They cleared after a couple of days, but it came back and ended up dying a few days later. <Many possibilities, here; including mycobacteriosis....> Now one of the two barbs left started chasing the other and nipping on its fins until it almost had none. So I decided to get three more tiger barbs to keep them in odd numbers.  <Very aggressive nippers; watch that they don't harass the other fish as well.> A few weeks later I noticed my golden angel had this white dust on its body. After reading I found out it was velvet. <Aaaaaargh! Serious bummer.> When I looked around the tank the black fin shark also had it. I did a 40% water change and treated the tank with copper. <Oh, yikes! Toxic/deadly to some of the fishes in your tank.> Kept the temperature on 80*. Next day the angel and the shark died and most of the other fish after that. I decided to get a 20 gallon set up and keep the fish that weren't sick (black ghost knife fish, the Pleco, and the two ruby cichlids). <Surprising that the knife and Plecs survived the copper - delicate fish.> I've done the constant water changes to fight the ammonia spike and it's been pretty good so far. But now I notice that the black ghost knife fish bottom jaw looks like it is decaying. I wish I could show you a picture. <I wish so, as well, but am pretty certain this is water quality related. Be sure to maintain ammonia and nitrite at ZERO, nitrate below 20ppm, with water changes.> Could you please tell me what could be wrong now? Cordially, Ivan. <Though it's entirely possible that these fish did contract velvet, I would lean more toward an environmental issue with this deterioration. Improve the water quality, and observe very, very closely.... and, as you've learned, in the future, quarantine all newcomers to your tank. Wishing you the best, -Sabrina>

Training a black ghost knife fish  9/22/05 Dear Mr.  Fenner, I have a black ghost knife fish that I have had for a month.  He is now about 7" long and very healthy.  He eats flakes in the morning and at  night, occasionally I give him some freeze-dried Tubifex worms.  What I  would like to know is how you teach them to eat out of your hand. He seems to be  a smart one he figured out the flakes were edible on his own.  If you know  how to do this I would really appreciate it. Thanks for your  help, MDM <Try feeding small amounts of meatier foods, more frequently, particularly just with some light on outside the tank (not in... too bright). Takes time, patience. Bob Fenner>

Black Ghost Knife Feeding Have you ever known a Black Ghost Knife to eat flake food because odd as it sounds mine just did... usually feed him on freeze dried Tubifex worms and brine shrimp and was shock not only to see him come out in the light and feed but to snag some flake away from my Gouramis and clown loach. <Have seen these intelligent fish eat most everything... do need meaty foods to sustain themselves though. Bob Fenner>

UFS (Unidentified Freshwater Specimen) Hello again, Mr. Fenner! On my yesterday's trip to my LFS I spotted in one of the freshwater tanks, along with some Discus, a black sort of "file fish" thin) around 2" long; it also had a white stripe near the head and a peculiar way of swimming, since it only uses a long ventral fin to do it. Not recognizing the species I asked the employee the name of it. The answer was: "It's a Roberty... but that's all I know!". Can you please give me any clue of it is, or a positive ID of this specimen??? <Umm, sounds like a "Black Ghost Knifefish" to me: Apteronotus albifrons. Please take a look on the net (at least fishbase.org) under these names. Bob Fenner> Thank You, best regards ! Luis Santos

Black Ghost To Whom It May Concern, I'm writing to you from Hilo, Hawaii. I'm looking for some information on a fish call the Black Ghost Knifefish; (Apteronotus albifrons). If you have a book or magazine on this type of fish, please let me know right away. <No books that are hobbyist oriented. You would do well to read through the material listed on this species on fishbase.org, ask, search the hobbyist listservs. Is there particular information you are looking for? I need to work up a survey piece for our WetWebMedia.com site on all "Knifefishes"... and could use this as a treat. Bob Fenner> Thank You, John Rosario  

Breeding black ghost knife fish? Hi. I was wondering if you could help me out on how I can tell the sex of my black ghost knife fish, and how to get them to breeding. <It's almost impossible to distinguish male from female in this species. Captive breeding has been accomplished in Australia, but details are sketchy. You might try keeping the pair in a very large tank, feeding them only the best of foods, and then see what happens.... That's about all I can suggest. Best of luck with this endeavor, and do keep a log so you can write up and publish an article when you're successful! --Ananda>

Black Ghost Fish Hi   <Hello> I  am setting up a tank for a ghost fish and want to know what sort of plants are good for putting in the tank and what other fish are suitable if any <Tropical South American plants are my fave... ones that would, could be found in the same habitat. Tropica has a nice website that shows some of these biotopes... and maybe some sunken driftwood. Many medium sized characoids (tetra) fishes will go with this Apteronotus... as well as Callichthyid catfishes... even angels. Bob Fenner> Cheers Shelley Molloy

FW Ich, Ghost Knifefishes, Treatment Hello, I have a 20 gallon tank and I have a black ghost knife fish in it with ick.  I have heard that you cannot use ick treatments when there is a black ghost because it will kill them. <These fish are sensitive to many medications>   I remember hearing somewhere that you are supposed to raise the temperature instead.  Can you tell me how high to raise the temp. Or can you give me a better solution.  This is a very expensive fish and I like him a lot so any help you can give me so I don't lose him would be appreciated.   <Raising the temperature will likely effect a cure. If your other livestock can handle it, do raise it to the mid- 80's F. You can do this all in one day (do make sure you have adequate aeration... higher temp. results in higher metabolic rate and less gas solubility). And in a couple of weeks, when you are sure the ich is gone, do lower it slowly (about a half a degree per day) to the upper seventies. Bob Fenner> Thank you, Jeneane

Black Ghost Knifefish production? Word on the internet is that the Black Ghost fish (Apteronotus Albifrons) is being bred in Australia and Malaysia...any information on how its being done? Thank You, Richard Davidson  <Very interesting. Do know that other Apteronotids have been bred, raised in captivity (for science). Have not heard that this species was being produced commercially. Will be sure and check at the upcoming (May/June) Aquarama show in Singapore re. Bob Fenner>

Black Ghost Knife Feeding Hello fine fishy folks, GREAT website.  I have spent hours and hours here for the past couple of years and learned more than I ever thought possible.  Thanks for the effort you all put forth. I have a simple (probably paranoid) question for you. I have had a Black Ghost Knife (Apteronotus albifrons) for the past 2 years and he is a big boy!  Looks great and is my favorite fish.  He is health, velvety black with brilliant white markings on the tail (starting to fade on the head - from age?).  He is currently sharing a tank with 3 clown loaches, 1 fire eel, and 2 black kuhli loaches. My question is, what I feed the tank is Tetra flakes and shrimp pellets in the morning, and frozen cube (thawed of course) enriched Mysis and frozen blood worms in the evening.  Since the BGK is approximately 14 inches long, is this fare big enough for him to get enough to eat?  Should I try switching to larger shrimp/worms, etc.? Any input/opinions you care to share would be much appreciated.  I am probably just being paranoid, but can't stand the thought of him being hungry all the time and risk slowly starving him. Thank you and keep up the good work! Tom <<Dear Tom; What a great job of fishkeeping you are doing there! Your ghost is large enough to warrant more food, yes. Keep in mind this usually means more water changes :P You can try a few new things: Earthworms are a great source of protein, bought from your local fish 'n tackle bait store, or you can grow your own http://www.thekrib.com/Food/, live ghost shrimp from your LFS, chopped seafood from your local grocery: buy frozen shrimp, etc, and chop into bite sized pieces for him. It's also a good idea to soak your sinking shrimp pellets in some liquid fish vitamins, like Selcon or VitaChem (also sold at pet stores) so he is getting a decent staple. Have fun! -Gwen>> Black Ghost Knife habits Good day, I am writing to ask about the black ghost's behavior. I notice that sometimes it lays on its side in the Mondo grass I have in my tank.  Is it 'sleeping'?  Or is it sick?  I have never had a black ghost until my brother bought one for my birthday the other day. any answers would be appreciated. < The black ghost is really a cool fish. Unfortunately it is nocturnal and is rarely seen during daylight hours. If you really want to see him out and about then you can turn off the aquarium light and feed the tank some black worms or live brine shrimp. Just use the room light to watch him. In bright light they will hide in logs or caves until dusk when they come out to feed. They get big, up to 18 inches but got to be up there as one of the strangest aquarium fish.-Chuck> Thank you! Eric

Black Ghost Knife Hi Bob, Nice site. Looks like you've got articles on everything in here. Hence I thought I might ask some advice. I've been keeping fish for a few years now and last year I took on a Black Ghost Knife fish as a favor for my local pet shop. I am aware of how long this fish will live and how large it will grow and I plan on getting a 60g tank in December. At the moment I keep her in a 20g tank with a few tetras and a Betta but I have a spare (34g) tank that I've been using as a hospital tank for my marines. (I've added a pic of the big fella) Specifics are pH 6.8, Temp 25.4 'C. What I'd really like to do is swap the two round and have a good size tank to keep the BGK in. Thing is I can't really find out that much about them. I know it seems healthy, good color, eats well (even a couple of tetras once) and its very active at night. The fish has grown 1" in the last year (now 4") and now that I've given the rest of the community to my little sister (fast becoming an avid fishkeeper) I want to set up a species tank. Ideally I want at least one other BGK but sexing is impossible and I've read that they can be violent towards one another. Aside from these fish living in South America I know little else about their habitat. I was thinking of having a ground basalt strata with lots of spiral Val's and some floating plants to give better cover. Perhaps even some staged lighting to have a dawn dusk effect. If you give me a run down on the best kit to set up this king of tank what type of filtration, lighting, circulation and planting I'd be very grateful. Also should I go for a second juvenile and hope they grow up happily with one another, or is it better to stick to the one fish? < These are really cool fish. Unfortunately they are nocturnal and only come out at night or at dusk. They stay away from bright light. You might try red incandescent bulbs to observe them at night. They prefer clean soft acidic warm water and live food. They are prone to come down with ich and are difficult to treat. This could be because they are rarely seen by aquarists and  are often diagnosed too late. They like lots of shelter during the day so caves and logs are appreciated. Years ago they made " Black Ghost Houses" which were nothing more than clear plastic tubes with little feet on them. This way the ghost thought it was hiding. I don't know how well they worked or if they still available any more. These fish really don't see that well and get around by using a week electrical field like electric eels to get around. They get up to 18 inches and are being bred in Thailand.-Chuck> Kindest Regards, Carraig Tuomas

Black ghost Knifefish  hi, I need some advice concerning my ghost Knifefish, I've got a 5ftx3ftx2ft tank(400 litres) I have 1 rather large goby an Arowana 2 angels and 1 Geophagus brasiliensis a few kuhli loaches and a bristle nosed Plec, all of which seem to get on fine. last week I fell in love with a ghost Knifefish but since he's been in the tank I've hardly seen him, or seen him eat anything. the goby that I've got is very greedy and I'm worried if the Knifefish getting any food, what should I do???? any advice would be greatly appreciated, thanks Julie < Your knife fish is nocturnal and will only come out a night. If you put on a red light bulb at night you will see him out an about. To make sure he is eating I would turn out the lights and then feed the tank. They can be very picky and sometimes only eat live food. I would place some live black worms in the tank after I turn out he light at least once a week. If you ever got an elephant nose then I would recommend the same thing. -Chuck> 

Need Help I am at a complete loss, and I'm now turning to online resources in my desperate attempt to find a solution to my problem. I found your site to be very impressive; very rarely does one find a resource that contains such a wealth of valid information. I work at a large chain pet store, in the aquatics department. All of us in the department are extremely knowledgeable about fish and their care, and rarely have any problems with any of our fish. However, whenever we receive a shipment of black ghost knives or clown knives, the fish systematically die off within a couple of days. We have no problem with our brown knives, ever. We keep each species in their own tank, the brown knives in a larger tank with zebra Danios (they never come in large enough to eat the Danios), and the ghost and clown knives in their own smaller isolated tanks. We offer ample hiding spots for each type of fish. We feed each frozen food, such as bloodworms, nightly. Our pH is a little high, around 7.8, and our water hardness is through the roof, but our temperature is a consistent 78 F. We always carry juvenile fish; the knives never come in larger than 4 inches or so. We would like to carry ghost and clown knives, but not if it means continuous losses such as we have experienced. If you have any advice as to what we might be doing wrong, and what we might to do rectify this, it would be greatly appreciated. My thanks in advance. L Barker  <<Hello. I need to know if you guys are putting these fish into properly cycled tanks. I know it sounds simplistic, but it would make me feel better if you could provide me with information on ammonia levels, nitrite and nitrate levels in these tanks. The problem with being a store is that as the fish are gradually being sold, over time, the beneficial bacteria can die off without us being aware of it...then along comes a new shipment, and twenty fish are suddenly put back into tanks with limited bacteria. The ammonia level can skyrocket the first few days, resulting in sick knife fish that never fully recuperate due to all the stress from shipping combined with new surroundings...and undoubtedly bad nutrition before you received them. Also, smaller knives are even more sensitive than larger ones. You may have a better survival rate if you can specify 3 inches or LARGER when you order your knife fish. Try, and see. In the meantime, prepare your knife fish tanks either by keeping them full of other species at all times to keep the biofilter alive, or by using pure ammonia to keep the nitrifying bacteria alive, until the shipment lands. You can also try running some peat moss to help lower pH and hardness levels, though these, in and of themselves, should not be enough to kill all the newcomers alone, but it doesn't help when added to the other stressors the fish are facing. Also, keep in mind that knife fish are aggressive amongst each other, and make sure to provide plenty of PVC tubes for the ghosts, at least one per fish!! Keep the lighting low for the first few days, as well. You can cover the tanks with Styrofoam lids to diffuse the lighting, or leave the lights off entirely. -Gwen>>

Melafix with Ghost Knife Hello Crew, This is my first time asking a question on www.wetwebmedia.com. I have a 120 gallon tank with 4 Silver Dollars, 1 Distichodus noboli, and an 8 inch Ghost Knifefish. I purchased these fish about 4 days ago, and 2 days ago I noticed that 3 of the Silver Dollars have their fins nipped and their are black and grey marks( not spots) on their tail. I think it's because of the nipping. I'm not sure if the Distichodus was the culprit or the other Silver Dollars. My question is can I treat my tank with Melafix without the Knifefish being harmed? How much Melafix should I add if I can treat the tank? Thank you, Greg >>Dear Greg; Follow the instructions on the package. Also, you should get your water tested at your LFS for ammonia, nitrite, and nitrates. Is this a new set-up? Either way, your water quality may be the culprit, followed by the Distichodus. Silver dollars will not beat each other up enough for you to need to treat their tank. Look into the other potential problems. -Gwen<<

Black Ghost Knifefish sensitivity Crew - To my eternal shame, and by neglecting quarantine, I have killed the Black Ghost Knife that lived with my discus, angels and L-numbers.  I neglected QT and got whitespot in the tank.  Got reliable treatment, and halved the dose as I knew knifes, like L-numbers and clown loaches (there' one of those in there too), put in med for whole tank.  Well knifes are a lot more sensitive than I thought.  Checked back an hour later, all looks ok.  2 hours later knife is not looking good, move to another tank FAST, 3 hours later dead.    Lesson one - QT Lesson two - QT for sure if you can't treat the tank because of sensitive organisms >>Wayne, sorry to hear of your loss. Out of curiosity, which medication did you use? Some meds are stronger than others, and some have completely different active ingredients. I have treated black ghost knives with Super Ich Cure and higher temps, at half dosage, with good results. Which fish introduced the ich? And how long were the ghosts in your tank? I agree that anyone keeping discus should quarantine all new fish. It's a sensible thing to do :) -Gwen

Black Ghost Knifefish and meds  Gwen -  JBL Ektol, which has proven pretty effective for external parasites in the past, but has to be watched as it can/will kill your filter. I usually add  half a dose and watch carefully, but not carefully enough this time.  The source - blue rams, introduced several weeks before.  Royal Panaque, Bristlenoses, L-33 and clown loach all fine. But the timing  tells me it must have been the meds. Symptoms were fish just became less active, hid, was obviously distressed.  Wayne  >>Wayne: Hi again. I am unfamiliar with JBL Ektol. What are the ingredients listed on the bottle? There are anti-parasitic meds out there that won't harm your biofilter, at least, not a complete kill-off. I know some meds like malachite green/Formalin mixes can, but only in new set-ups where the biofilter is not mature enough to withstand a bit of abuse. In established tanks, there should be NO noticeable bacterial die-offs. I would assume that the JBL product is a bit strong, perhaps too strong for the more sensitive fish, if it is capable of killing the biofilter I would be leery of using it at all...what were your ammonia/nitrite readings after the treatment? -Gwen<<

Black Ghost Knifefish and meds - 2 lessons learnt the hard way Hi Gwen - according to www.jbl.de..... it doesn't say. I should have stuck to the advice 'if you don't know what it is, don't put it in your tank'. I'd rather have used punktol, but I've found this to be pretty ineffective at reduced doses (as I required) in the past. Ektol is a general parasiticide (?), bactericide... Ammonia, nitrite were fine afterwards - I'd expected some hit? <<Yes, but it can take a couple of days, so check your ammonia again after a day or three, just to be sure. I will try to find some info on this product, but at any rate, we know it doesn't work well on BGK's... :( -Gwen 

Ghost Knife Turned cream I have had my beautiful Ghost for over 8 months.  He's only about 5 inches long.  Recently I have noticed, that he has turned a very pale shade of light tan. <be sure to check to see if his skin is turning the color, or does it appear to have a "dust" like coloration to his body.  It might be Oodinium (otherwise known as velvet). The visible symptom of this disease is a fine grey-gold to whitish 'dust' on the body of the fish. Fish will  usually show very rapid gill movement during this time. The disease is caused by a protozoan parasite, and may be triggered by exposure to ammonia and nitrite,  or excessive nitrate levels. That is if it appears to be something on the skin.  I've never heard of a ghost changing his color before.  Have you checked his water parameters lately?  Make sure that the ammonia levels aren't that high.  and be sure to keep up on the water changes.  If the fish isn't showing any signs of stress or sickness then I'm not sure what is the best course of action to take.  I wouldn't want to add a medicine to the water and stress it out if it's not needed.> Nothing has changed in the tank-no new fish added, etc., so I don't know why he would be stressed.  He still bobs to the top to eat.  Have you ever heard of this? <I haven't heard of this happening with a ghost knife, I would keep a close eye on him and make sure if you start to see any problems, or if the fish starts rubbing itself on objects in the tank to move it to another tank and start medicating it accordingly.> Ren in Montana <Good Luck with the fish. -Magnus>

Off-colored Ghost Knife and Oscars with Angels - 02/22/2004 Magnus... <Sabrina, today, hope all is well> Thought I would update you on my ghost who lost his color. I put him in my 5gal guppies tank.  Thought that would be best - no one to intimidate him.  Of course, he loved the old car for his home, and as expected, the baby guppies all disappeared.  Had to make a decision of sacrifice to hopefully keep him alive.  I noticed a bit of black coming back (due to fresh "sea food" I'm sure...), <And you'll surely have more baby guppies in the future, no worries.  Good that they have contributed to your ghost's well-being, a worthy cause, IMO.> but he has outgrown the little tank, <Heh, to be expected!> so I moved him to the 38gal.  This tank consists of Parrots, Tiger Barbs, and a handful of misc.  The red tail shark is probably the most aggressive, but lives in harmony with the others usually.  Once in awhile he'll chase the barbs around.  So far the ghost has found an ornament to hide in and seems to being doing okay. <IMO, all of these are too aggressive as tank mates - do keep an eye on him, watch closely for splits in his fins or any other signs of distress.> Another question....I have a 60gal octagon with two Oscars, two tins, <Hmm?  Ahh, tinfoil barbs, yes?> two fire mouth cichlids and two angels and a silver dollar.  All is well with the combination at this point, but as the Oscars grow (one is about 6"), do you think the angels will be okay?   <Not at all, not in this size/shape tank - I would consider all tankmates grossly at risk of harassing/harming one another as they "grow up" - the Oscars will likely require a tank of their own, if they're getting on well, they've likely paired.  Removing them to their own space will give you some wiggle room for the rest, and the Tinfoils are the next biggest worry - topping out at about fourteen inches.  Fortunately, they are durable, and slow growers - I would remove them with the Oscars.  A tank that is big on surface area (er, not a hex/octagon/tall tank) will do best for the four.> One angel is quite large, the other only about 2 1/2 inches.  I know there is not always a rule to go by, but do you think I should move the angels? <The Oscars and Tinfoils will need a larger tank in the long run.... not so much larger in gallonage as in usable space.> FYI-my "herd" has gone down in numbers.  I have been very blessed to have had 6 adoptions in the past two weeks.   <Wonderful!!> Down to 13 dogs-seems so quiet.   <Sounds like you're doing quite well.> Thumbs up to your girlfriend for helping the shelters and rescues-wish she was here! Have a wonderful day.  Ren <You, too.  Wishing you well,  -Sabrina>

Ghost knife with cichlids My son has had a black ghost knife fish for four years. He is about 9 inches.  We, being ignorant, were keeping him in a <gasp> 10 gal. aquarium all this time. <yikes that is a bit small...> The last few months he ("Sonar") would stay out of his ghost tube most of the time and do loops a lot.  We increased his feed. <that happens with Knifefish small tanks seem to have them get restless.> Anyway, at Christmas I bought him a 29 gal. tank <wow> thinking that would be wonderful.  It came with an Aqua-tech 20-40 power filter. <I know you're laughing>.   <Any filter is better than none, just have to make sure the water parameters are okay.> Being ignorant again, in regards to the new tank cycling.  I also bought two convict cichlids to keep him company.  My thinking was they could hold their own with him since he killed the Neons and Bala shark my son used to have.   <be cautious with any cichlids and Knifefish, cichlids are nippy things, and if a Knifefish should loose his anal fin (which is it's only real propulsion) then it is done for.  I try to keep my Knifefish with tankmates that I know won't bother it.> I used the Stress-coat and Stress-zyme.  The ammonia levels got really high.   <A fish that size is bound to put out some high amounts of waste and ammonia> I did have a knowledgeable man at Petco advise me on changing out the water and doubling up on the stress-zyme.  So I did that two times the first week, about 25%. <The stress-zyme isn't really helping the ammonia levels, it's helping the water additives in your water.  The water change is helping the ammonia levels. So keep up on the water changes.> I kept asking about using our filtered drinking water  at fish stores and no one seemed too concerned.  We have rural chlorinated hard water but a water softener, which is what I used for the tank.  I now plan on using the filtered for the next change out. <many Saltwater people prefer using filtered water for their tanks, nothing saying you can't use it.  Just that it can get expensive.> Should I still use the chemical additives? <It's not hurting the fish any, so you can keep doing it, just only add what is recommended on the package.   Good luck with the knife.  When they get older you will have lots of fun.  I have a friend that feeds his ghost by hand.> My main question is should I get rid of the two cichlids?   <I would, they run the risk of damaging the knife.> Since all this I have spent a lot of time reading and learning ( a good thing) about these guys. <That is a very good thing.  Research research research!  you will have more fun if you know what to expect.>   I think they are both males.  The bigger one (they're both about 3 in) chases the other a lot and so he hides by Sonar which is sometimes in his tube with him.  I just noticed a couple slits in Sonar's ventral fin now and I'm feeling very guilty.  Other than that they seem to not bother him.  He still does his loops and does come out to feed when the light is on although he is spending more time in his tube again. Also, I have learned we really didn't have a biological filter so I stuck a trickle filter sponge in the power filter where the water flow out hoping that will help. <any more filtration is better than what is on there.> I'm pretty sure I'm going to find a home for these cichlids even though I enjoy watching them.  I thought of just getting rid of the aggressive one.   <You can set up another tank for them.  Cichlid tanks are extremely rewarding.  Get a male/female pair, and within 3-4 years you will no doubt be an expert and breeding them for you LFS!> Sonar is my biggest concern.  Should I do anything else?  Any suggestions you have would be greatly appreciated. <I would separate the fish, chances are high that they will pick at Sonar when you aren't around.  Give some thought into setting up a cichlid tank, I'm sure you and the family will really enjoy them!> Sheryl in Missouri     <good luck Sheryl.  -Magnus in New York>

White Furry Growth on Black Ghost Knife Hello Web Wet Media Crews, Happy New Year. "Houston", we have a problem! My 16cm Black Ghost Knife is covered with furry white "slim/growth" all over its body, including its eyes. At first I thought it was body fungus <You are right it is fungus.  It's a true fungus that attacks the outer layers of the fish. Fungus prefers cool temperatures, acidic conditions, so check the temp of the tank and what the pH levels are at.> used "OCEAN FREE" medication. I have no idea what it contains but it turned the water really green. <Not sure what actually does turn it green, but it's suppose to do that.> I did a partial water change. I increased the water temperature from around 26 or so to 32 Degree Celsius. <Make sure you medicate the exact way the package tells you to do so, doing water changes during treatment simply removes the medicine already in the tank.> My BGK fish stopped fishing and rest on the bottom of the tank for the whole 3 days. When I used an object to lightly scrape its body, the whiter furry things is easily peeled off. <It's best not to physically scrape the fish, you run the risk of scraping the fish, damaging it skin, or bothering what's left of it's protective slime coating.  If you should scrape the fish, the bacteria can get deeper into the fishes skin causing more problems.> This happened quite often. What seems to be the problem? Is it a fungus growth, water conditions or other ailments? <The fish has true body, mouth and eye fungus, a fungus infection -- treat with MarOxy. Use Maracyn-Two or Maracyn or Tetracycline or TriSulfa to prevent secondary infections.> You guys have provided me with many valuable tips that keep my fish surviving till now. I hope you can help me with this again. Many thanks.    <Hope that helps.  I hope your knife gets better! -Magnus> <<Malachite green is likely the ingredient in the medication that turned the water green.  Malachite green is toxic to ghost knives, for future reference.  -SCF>>

Re: White Furry Growth on Black Ghost Knife. Passed Away Hey Magnus. Just a few minutes I sent you a reply, my fish passed away. <I'm so sorry to hear of your loss.  It is a very sad thing when we lose pets we cared for.> Nevertheless, I would like to thank you and the whole crew for the help. <I'm just sad that I was unable to help you save your fish.  But remember we are hear to help you, so ask a question anytime.> 1 more question.... can I bury my fish in my flowerpots? Is it safe to do that? <You would need to have a large flowerpot, and you run the risk of having loads of bugs and such coming into you flowerpots after the body of the fish.> Will the disease be spread to the plants? <Fungus can spread to the roots of certain plants provided the soil is acidic and moist.  I really would worry that the decomposition will affect the pH of the soil and hurt the plants.  I would probably dispose of the body in a different way.> What is the best moral ethnical way to dispose one's beloved died sick fish? <With large fish I have actually buried them in the back yard.  Please don't take offense to third, if you have no yard, you could always seal it in a multiple bags and simply deposit it in the trash. some people became far to attached to do that to the fish, and would hate to "throw them away".  I would try and find a place to bury it if you want, rather than throwing it away.  A park or some other area would be better than your flowerpots.   I'm sorry to hear of your fishes passing, I do hope that you know that you had done your best to care for it.  -Magnus>

Ghost Knife Hi, I recently bought a new fish from a local pet store and he is doing just fine.  The guy that sold it to me said it was a Black Ghost Knife fish, although the fish does not have a white stripe down its back or a white band around its tail. It does, however, have a very dark brownish red stripe where the white one normally is and no band of color on the tail. The fish's body is jet black. Is this a Black Ghost? If you know the answer could you email me back? Thanks! <Hmm..., not quite sure, do you have a picture?  Check out Monga bay and Fishbase to see if you can find a match. -Gage http://www.mongabay.com/fish/knifefish.htm http://fishbase.org  > That's Black the Knife Hi guys and dolls.... <Hello, Sabrina with you today> My question refers to the black ghost Knifefish.  I saw some at my LFS for $25!! Expensive but they are really cool. Now I know they are supposed to be black with a white stripe running down the top, and a white ring on their tail. The LFS had about 9 of them, but some of them had a yellowish stripe instead of white. Is this normal or are they sick? Thanks for the info. <I've seen older ghosts have yellowed looking stripes as well as a graying body, but when young, they should be quite black with rather vivid white markings.  Do keep in mind that this is a shy, nocturnal animal, very aggressive within its species (one to a tank, basically), and reaches a whopping 20 inches....  A very large tank would be quite necessary to house one of these beautiful beasts - and no aggressive fish, nor any small fish, could be housed with it.>

Large Fish Compatibility I have recently bought a striped shovelnose and a black ghost together and the pet store said they were compatible, which they are. they don't bother each other. later on I bought a gold Severum and 2 clown loaches, which the pet store said that the Severum and clown loaches would go good with the black ghost knife fish and the shovelnose. nothing has happened yet because they are all pretty small. but I was telling someone what I had in my tank and they said that I shouldn't have listened to there advice because the black ghost knife fish would be fish food sooner or later. so I was wondering is that true? I do know that the Severum is compatible with all the other fish but I couldn't find any information on the black ghost fish. if you can help I would much appreciate it.         thank you          sincerely, Lindsey <Hi Lindsey, I am scared to ask what size tank you have.  These are all fish that get really large.  The shovelnose can get close to 2ft, and the Ghostknife will not be too far behind.  In a large enough tank you might be ok, I personally do not trust large catfish with smaller tank mates, they have a tendency to eat them.  You can find more on the Ghostknife at the links below.  Best Regards, Gage http://www.wetwebmedia.com/FWSubWebIndex/knifefishfaqs.htm http://www.mongabay.com/fish/knifefish.htm  >

Black Ghost Knife Fish Fins Woes Hello. <Hello! Ryan with you today> I need some answers badly. One of my 2 Black Ghost Knife fish's anal fins splits... it is like they are not joined as a single whole piece anymore. It became 1 part by 1 part.... the end will run perpendicular from the body and all the way to the edge of the fins. Something like strands of hair, but thicker.. about 2mm width. It is something bad? Why is it happening to my fish? How can I solve that problem? Please help. Thanks <OK, here goes.  There are a few things that could be causing this.  Is there any necrotic tissue around the fraying?  Is the edge of the tear whitish?  If so, we're almost certainly dealing with necrotic ulceration of the fins, commonly known as fin rot.  Problem is, many things can be causing the stress leading to this.  They are as follows: Parasites, overcrowding, low oxygen levels in the tank, bullying or poor water quality.  A secondary bacterial infection almost always comes hand in hand with fin rot.  You're going to need to quarantine this fish, and properly medicate him.  If you do this quickly, he may re-grow the tissue.  The underlying cause of this may seem hard to find, but stay with it!  This is a fish that needs lots of hiding places-have you given him some?  A section of plastic PVC pipe in the quarantine tank should be a helpful tool in giving your fish a chance to recuperate.  Ryan>

Black Ghost Knife Fish Hi again <Morning! Ryan here> Thanks for your advice previously. Using half dosages of Protozin seems to have cleared my tank of ich. <Great> I lost a clown loach, but the symptoms have gone from the other one, as well as the few spots that were on the knife fish. <Clown loaches so sensitive to ich- their worst drawback>  But the problem I have now, is that the knife fish has some white streaks down his side, running from about the middle towards the tail and the ventral fin. <Eek> I noticed it after a week of the treatment when I repeated a dose (as Waterlife suggested) because there were still a few spots on the clown loach.  My guess is that either there was just too much medication for him to handle and it has strained him (or reduced his slime coat somehow) or that he has a secondary infection from the ich. Do you have any suggestions? <Could be a combination of both.  Pay special attention to water quality, and make sure he's eating well.  Give it a few days before any new treatment- have you removed the old medication from the water?  Don't get too stingy on the water changes-5% a day until he clears up.  Perhaps this will be of aid http://www.wetwebmedia.com/FWSubWebIndex/fwfshparasites.htm Good luck! Ryan> Thanks and Kind Regards Graeme

Black Ghost Knife Fish Hi there <Hello> I came across a page where you discussed ich, and was just wondering if you would be able to help. I need to treat my tank for Ich but I don't want to harm the knife fish. I have a product called Protozin by Waterlife which mustn't be used if Elephant-nose fish or rays are in the tank. Although it doesn't mention knife fish, I'm concerned about using it because I've heard they're sensitive to Methylene blue. Since I have Clown and Kuhli loaches, I only need to use half the dose, but I just want to make sure this will be alright for the knife fish. Any advice would be greatly appreciated. Regards Graeme <I share your concern and would NOT use this medication in the water with the Black Ghost Knifefish. It likely contains malachite green (is it a dark blue color that stains all?) and is indeed toxic to small- or scale-less fishes. Seek out other means (e.g. temperature increase) and safer chemical treatments for this ich condition. Please see here re: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm Bob Fenner>
Re: Black Ghost Knife, ich and bluish med.s
Hi Thanks for your reply! Nowhere on the product does it say that it contains Malachite green, but it is a blue liquid that seemed to stain my fingers when I opened it. The thing is, I've been told that clown loaches are very sensitive as well, so with Protozin you're supposed to only give half the dosage. <Ahh, I do further suspect that malachite is a principal ingredient here. You might look up this term on the Net along with the words "fish medication"> If the loaches are more sensitive than the knife fish then it shouldn't be a problem, so I'm still confused. <In soft water they're both about the same sensitive> I may try it on them in a quarantine tank (although mine has nothing but a heater) but then I'm not cleaning out the whole tank, and then I'm not preventing the knife from getting ich as well. My temperature is already at about 26/27 degrees C. Do you suggest water changes too? <No to the water changes, as these may stress the animals more than what good they do. I would elevate your temperature to about 30 C. (86 F. for Yanks)... over the next day or two. Bob Fenner> Regards Graeme

Black Ghost Knifes Hello. I read the FAQ but I am unable to find the answer for my question. I have a rectangular tank is 16" x 9" x 11". But I have 2 ghost fishes. It is healthy for the fishes? I noticed that they sort of dance/swerve/bite each other in that sequence. I am afraid that they are trying to kill the other off. I bought a volcano rock (that's what the shop says) for the fishes to hide. Seemed like they don't share. Should I buy another one to keep the other happy? 1 last thing, the fishes don't eat the flakes floating on the water. Instead they scoop around the top edges of the tank. Thanks. I really those answer. Please <These fish need a larger tank, at least 55 gallons even that may not be big enough to house 2 of them, they are aggressive towards their own kind.  Check out the link below for more information on these fish.  Best Regards, Gage http://www.mongabay.com/fish/knifefish.htm  >

Ghost Knife with red spot on tail Hello again, I contacted you earlier with an Ich problem with my BGK (see below). He's been recovering beautifully thanks to your help and I've been lowering the tank temp down to 81 from the 86 it was at. However, for some reason, within the last 24 hours he has developed a red spot, like a blood spot on the white portion of his tail. It's not very large and doesn't span the width of his tail, only a small portion, but enough to notice clearly. I'd attach a picture but I'm unable to get a decent enough shot. His appetite is off a little also. He's eating the brine shrimp but not as voraciously as usual. Water is still testing same as listed below. Could he have hurt himself. <Yes. This is the most likely explanation> He has no tank mates at all and only items in tank are a large piece of wood and a ghost house (which he loves). He also spends a lot of time by the surface and seems to enjoy running up and down one of the powerhead tubes in the corner. <All normal behavior> I installed a bubble wall to increase oxygenation since we were upping the temp so much and have left it going full on even with the tank temp lower. <Good> Could that have anything to do with this? <Not likely> I'm also still treating with half doses of the Aquarisol but only every other day now.  Any suggestions? Thanks so very, very much!  Jennifer <Just to keep on doing what you're doing... all will likely be well. Bob Fenner>

Re: Ghost Knife with red spot on tail UPDATE - TAIL ROT I have an update to this last note - the red spot must have been the onset to tail rot. I'm completely at a loss on this one. We just got him over Ich and now this - I don't understand. The water levels are very good... pH 7.6 - ammonia was at 0 - Nitrates were very low - water hardness is 60. About 1/8th of his tail has disappeared since yesterday. I did a 30% water change, added 2 tbsp of salt, Pimafix and increasing the temp again. This tail rot problem didn't rear it's ugly head until the temp had gotten back down to 81. His appetite was good tonight - he loves bloodworms. Can I use an antibiotic like Maracyn or tetracycline with a BGK? What else can I do for him? Thank you! <You can use an antibiotic... I would go with the Maracyn/Erythromycin... is mixable with all else you're doing... and I would re-elevate the water temperature till this problem is gone. Bob Fenner>

Re: Ghost Knife with red spot on tail, now white "worm" hanging from gill Good Afternoon Crew, Sorry to inundate you with issues with this one BGK but things just keep going wrong. After curing him from Ich, he got tail rot, that seems to be under control now as it doesn't seem to be deteriorating any more. I've started him on the Maracyn-two tablets as of 36 hours ago per your instructions. However, this morning I came down to check him and he has this long white wormy looking thing hanging out from his left gill. (Pls see attached pic) What on earth am I doing to this poor animal? I've rechecked the water and Ammonia is 0, PH is 7.6, Nitrates are less than .25. And I had the water checked at the local fish store to verify my results and they also concluded that my water tests fine. He's the only fish in this 55 gal tank. His appetite is a little off. He used to love brine shrimp but last night he'd suck them in and spit them back out. Then I added some blood worms because I wanted to make sure he was eating and he ate those although less than usual. I've researched gill disease etc and can't find anything that denotes a while long wormy thing coming out through the gills. Any ideas as to what it could be? I'll continue on the Maracyn for the duration, but is there anything else I should be doing to the tank to "Cleanse" it so to speak of anything else I could be harboring?  Thank you so very much for all your help. < Your poor Black Ghost Knife also has gill flukes. He should be treated with Fluke-Tabs.-Chuck>

BGK Question I have a Black Ghost Knifefish (4-5") for almost 6 Months now. I have noticed that his Black Body looks like it is now covered in a off-black to grey slime or flour-like coating. I think it's ich and I know that ich is hard to treat on these fish. <Yes> I raised the temp. to the mid- 80's like your site suggested. <Good> His tankmates are a Pictus Cat (3-4") and a Blue Gourami (2-4"). The cat showed dome cysts, but after the temp increase they disappeared. I can't afford a quarantine and he is in a 29 gallon, which is to be upgraded to a 55 as soon as space in my house becomes available and I can get more money. I have bought Rid-Ich+ just in case it can be used. Should I use the medication? <Yes... at half strength... removing any carbon, chemical filtrants... keeping close watch on all, being ready to change water...> What else can I do? I love and have become attached to this fish and I don't want to lose him. Can you help me, I want to save him, raise him up and have him for a while? Thank You, John <Read re: this disease, these fishes... treat carefully and all should be well. Bob Fenner> 

Ghost Knife sick - please help Good Morning - I came across your FAQ on the Knife fish and was very appreciative. I read through much of what you had and it was helpful but not sure if what my fish has is Ich or not so not sure to use the info your site kindly provided. Hoping you can help as I really love my fish and am very worried. Here's the stats... 55 Gal tank - PH is 7.8. <A bit high for the fishes listed...> Tank established for 8 months. Put in feeder goldfish about 3 weeks ago to feed Arowana and two weeks later my fish are dying. <Not... an uncommon problem... Please read here: http://www.wetwebmedia.com/goldfshfd.htm  this practice, feeding feeders, is a HUGE source of aquarium livestock mortality> Have removed feeder fishes from tank altogether.  <Too late> Water tested by local shop and hubby and both said it tested very good just pH a little high.  Just lost my Yo Yo Loach and Arowana with no visible signs of sickness.  Yesterday morning I checked my tank to see my Black Ghost Knife with white spots all over - but not like I've seen Ich before - like little salt sprinkles. These white spots appear to be more flat looking and more grouped. Please see attached picture. <Does look like ich... though could be another parasite... most all are treated similarly> He is eating and acting normally.  Was told to do following treatment but have seen no change as of yet; raise water temp to 82 degrees, use AquariSol 12 drops per 10 gal, add sea salt 1 teaspoon per 10 gal and remove charcoal from filter and use PimaFix 1 tsp per 10 gal. I'm worried that I'm overmedicating. <Might be... as Knifefishes are intolerant of the poisons that are used to treat such infestations... I would raise the temperature to mid eighties F., not use the PimaFix (it's of no use), and use half doses of the AquariSol (a copper sulfate solution)> Should I be doing water changes?  <Yes> Will that amount of salt hurt my BGK? <No, should help more than hurt> I'm worried he's not tolerant enough for it. Any suggestions are greatly appreciated.  Thanks so much!  Jennifer Welker <Have you read the article and FAQs on ich on WWM: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm  The FAQs are linked (above, in blue)... Bob Fenner> 

Ghost knife? Hi there guys,<Hi Guru, MacL here with you.> Absolutely love your web site.. I was wondering if you knew what size tank I would need to get my ghost knife to grow to its full length, and also roughly how big it would get in a 900L tank (approx 240 U.S. gallons and  200 UK gallons). <Guru I need a little bit of clarification. Do you mean a black ghost or one of the other types of knife or bony fishes? If you take a look here you might find your answer, otherwise if you can clarify for me a bit we can go from there. http://www.wetwebmedia.com/FWSubWebIndex/knifefishes.htm> Regards Guru

BGK tank mates Hello, I have a Black Ghost Knife that I've had for about 5 months, about 4 inches.  He shares a 60 gal. tank with my Pleco and 2 Platy's.  I have a Fluval 404 for filtration and maintain the water regularly.  I'd like to get bigger, livelier, compatible fish for the Pleco and BGK.  I have a feeling the Platy's will eventually be food for a larger fish.  I'd love to get an Arowana but think it will outgrow the tank too soon and eat my BGK.  What about Oscars, Eels, Catfish, Red Tail Sharks?  I had a clown loach before but it was very spastic and swam anxiously in circles and eventually died.  What fish and how many can I add to my tank that would be best fit for the BGK and Pleco?   Thank you. Kristen <Hello Kristen, I'm afraid for what you want to keep in your 60 will certainly exceed the capacity of the tank when the fish get larger.  Keep your BGK and your Pleco and maybe add a red tail shark.  James (Salty Dog)>

Re: BGK tank mates Thank you James.  If I only add the red tail shark, is that enough for a tank of this size?  I've heard that I should be keeping 9 fish in my tank at all times for natural bacterial purposes.  Are there any other fish you would also recommend? Thanks again. <Kristen, Both the black knife and the Pleco will grow quite large so I am basing that on future growth of the fish unless you plan on getting a larger aquarium in the future.  The main thing is to monitor your ammonia levels.   When you add a new fish, check these levels for a week or two to make sure the biological system can handle the extra load.  James (Salty Dog)>

Black ghost knife with ich Hi I have a Black ghost knife fish who is a new addition to my tank - though I have owned them in the past and have learned the * hard way* that these fish need a lot of individual care. <And don't "like" ich medications> through research and experience, there has been a great learning curve for me -  My tank is 29 gal with only 5 other fish who have been stable and healthy ( 2 are Discus and healthy). <This tank is way too small for even just the Knife... or one Discus> 2 days ago, I bought a 4 inch BGKF who has a great personality but the aquarium shop I got him is only 75% reliable  - has a fair number of unhealthy fish)- my tank has been quite healthy and I do 30% H2O changes every 2 wks w/ gravel vac. <I take it you did not quarantine this new addition>   Today, my BGK started to show a number of ich spots - I killed my last BGK with Rx in the main tank for another sick fish - <Very common> (ironically - the 1st discus I got had a good case of hole in head!) I bought this fish because I loved the personality of this fish... - I need to *save him* - what should I do? all readings on my tank are normal ; ph is 7.8, Soft H2O, lots of hiding places sterilizer always running. Peggy <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm and the Related FAQs (linked, in blue, at top) and: http://www.wetwebmedia.com/FWSubWebIndex/knifefishfaqs.htm I would use half doses of AquariSol, elevate temperature to the mid-80's F... And get a larger system for this life ASAPractical. Bob Fenner>

Parasitized Knife? Questions about life have a Black Ghost Knifefish (4.5") that I suspect has ich or velvet because I see a light (dull white) flour-like  on one part of his body. He also has it under his gill area, his head stripe is also yellow? <Do come this way> Is this Ich or Velvet? <Could be either or neither> His tank-mates are an angel and a Gourami at the moment. How long does it take them to grow to their final height? <Years> How long should I wait to upgrade from a 29 to a 55 gallon tank. <As soon as practical> I also have a  common silver angel that's tail fin is torn, I suspect a newly added Blue Gourami did it, will he be fine or is medication needed? <Not needed> I'm curious, how long do fish live without water? <Some species for hours... others for minutes> Also my Birthday is coming up (12/25 how exciting for me) <Yes, happy birthday!> and I am trying to persuade my parents to buy me a 65 gallon tank to start my first saltwater tank. Do you know any words that can help me convince them, because I love fish and I always wanted my own saltwater tank? <Perhaps tie the request with a wish of their own. Pledging yourself to study diligently maybe> I mean this is my only hobby and I also want to become a Marine biologist (will be taking a marine biology class in my senior year of high school which is in 2 years) Can you help me with everything listed above? Thank You and Happy Holidays Sincerely, John Queens, New York <Mmm, do make the effort to look into volunteer work at Public and private aquariums... perhaps even working a bit for a local fish store. Bob Fenner>

And the Crystal Ball Says.... I have a 29 Gallon freshwater tank and I think my Black ghost Knifefish has either ich or velvet. I'm not really sure if it is sick, but I bought medicine anyway. I don't have a Quarantine and I can't afford one. What should I do? I know I shouldn't but should I add the medicine In the tank he is in, because one or two of my other fish don't look good either? I want to  save my fish, especially my Black Ghost Knifefish, can you help me? Jahner <Will try, but we need more info. For now do large daily water changes. Use a gravel vac. Do not add the meds until we find out what's wrong. Why do you think he is sick? Is he showing spots? Do you test the water? If so, what are the readings? How often do you change water? What % do you change? Type of filter? How long has it been set up? Add any new fish lately. How about feeder fish? The more you tell us the better we can help. We know nothing at this point except you think he has Ick or Velvet. Sorry, we need more. Don>  

....Black Ghost, White Spots Well I do regular water changes (once very 2 weeks). I just did a 100% water change He is showing something like he is a little spot of flour. The head stripe is yellow and it is white under the gill area. I tested the what everything is normal Ph is 7.6. Ammonia, nitrate, nitrite is 0. I have had the tank since may and my ghost for 4 months. I added a fish 2 weeks ago. I have a bad filter (don't laugh) aqua-tech( any filter is better than none), and what do you mean by feeder fish? <Check closely for other white spots . The new fish may have introduced a disease called ich that may be somewhat tricky to treat on Black Ghost knife fish. You filter should turn the water volume of the tank times three every hour, with five times per hour being better. Feeder fish are small inexpensive fish used to feed large fish eating fish,-Chuck> Jahner

Another Black Ghost Knife Question I Have a Black Ghost Knife 4", If I put on my Aquarium light (which I haven't turned on  since I had him, 4 months) will it stress him out or kill him well because they hate light and are nocturnal)? He does have this ornament with holes in it that he goes in and out of (prefers that then the ghost tube), can he be in there if the light is on? < Black ghost knife fish are nocturnal and should have a hiding place to retreat to when the aquarium light is on. They should be fed just after the lights are turned off.-Chuck> Thank You Jahner

Lifespan of a Ghost What is the life span for a typical Black Ghost? How sensitive are they to moving to a new tank? Nicole <Couldn't find anything on lifespan so I'm not really sure. They do like soft acidic water conditions. Move them the same as any other. Float him in the new tank in a bag of his current water. give it 20 minutes or so, then slowly pour in some water from the new tank. Do this a few times over an hour or so and he should be fine. If you test water check the pH of both new and old. If they are the same, you just need to match temp. Don>

Ghosts, Knives and something else I have a 55Gal tank with only an 8in. Black ghost <max over 12"> and a 7in. African black knife <max 8 to 12">. I am trying to find what other fish I can put in the tank and how many of each would be appropriate. I used to have a Silver Arowana but he got way too big for the tank (27in) so I had to find him a new home. And my albino clown that I loved died after I took the Arowana out. I have tried Nicaraguenese, Bala sharks and a Green Terror but the cichlids seem to pick on the black ghost and the Balas are so twitchy.  I am thinking about trying another clown but it would be nice to have some fish they weren't always hiding. The tank is pretty lonely and I don't know who would be most compatible with the ghost. I don't want him to become fish food <Nothing that will fit in a 55 will take an 8" ghost> or make fish food out of them <Very likely, unless too large to fit in it's mouth>. Nicole. <The biggest problem I see is the size of your tank. A 55 is fine for what you have now. But you would have to add some fairly large fish to ensure they do not become a late night snack. And if you want a few of them, the 55 shrinks in my eyes. Clown loaches come to mind. They grow large, but slowly. Some of the larger Cory species would also be safe. Don>   

Breeding black ghost knives I have recently gotten interested in the BGK. When I'm interested I read every possible thing I can find, <Great>I have just read your section with the questions and answers for the people with the BGK (very knowledgeable and interesting by the way) <Thank You> and I noticed that not many people know about breeding these wonderful creatures. Well I looked and looked and it seems these people got it down. They even give tips to show the difference between males and females. Just thought you would like to read the page in your quest to help other people. It is very helpful. The site is: http://blackghostknife.tk/ I am thinking about breeding and this site is very helpful. Thanks, Steven Bertinato <Thanks for sharing. Don> Freshwater fish electro-sense question I recently bought an elephant fish. today my girlfriend surprised me with a black ghost knife. They are both about 3in and are in a 34 gallon tank with separate very good hiding spots. Will there 'electro-senses' clash? <There have been some studies on these electromagnetic fields generated by these fish but not much in the popular aquarium literature. But I am sure that they are aware of each other.> also how sensitive are they to salt? <These fish come from clean warm acidic water and have become very sensitive to salt.-Chuck> I use a little less then the recommended dose of aquarium salt(1tbsp per 5 gallon). tank also includes 6 glass cats and a blue lobster. thanks for your time. -Zac  

Ghost knife fish Hi,     I'm totally new to keeping fish ..... Recently, (about 2 days ago) I bought 2 knife ghost fish and a new fish tank for them .... I did not do research before buying them. So here's the problem ... the new tank is totally empty .. I haven't had time to go get those "hiding" places for them .... Only place they hide is behind a pump in the tank and they seems to be fighting for the space ..... Do I have to separate them using a partition in the tank ? Also one of the them had the fin like "broken" that like hair .. not in one whole piece as like the other... is there any wrong with it ? and what should I do ?, < Black ghost knife fish are nocturnal (feed at night), so they don't thrive in brightly lighted aquariums without suitable places for them to hide during the day. You really don't have to separate them as long as you give each of them their own shelter to go to  during the times you have the lights on. Get a couple pieces of PVC pipe from the local hardware store and throw it in there for now and they will be fine . Although the tank will not look to good with a couple pieces of white pipe in it.-Chuck> Thanks a lot Chasel

Re: Attempt to save Ghost knife fish Hi,     Thanks for the last reply. However, I'm sending this out in attempt to save my fish. I now have a tank with some plant and a log inside, 2 black ghost knife fish and a swordtail. They live fine with each other and I had been feeding them with flask and they ate them. < Sorry . don't know what flask is so I don't know the significance is if the black ghost knives ate them> But just yesterday, I notice my 2 black ghost fish are not doing well. They aren't moving much even when I turn the light off ....and not feeding either. I have no idea why this is happening. I don't have any tester to test the water condition. My last water change of 30% was 5 days also. They were still fine then. I don't know what else I can do. All I did was a 30% water change this morning hope to save them. Any similar situation to help ? < Well I guess we need to determine if their behaviour change is a symptom of something more serious. Try feeding some California blackworms, often called Tubifex still at some pet shops across the U.S. If they don't go for this look carefully for signs and symptoms of some things we can specifically treat. I really don't like to medicate a tank if it is not needed. In the meantime make sure that the water is up about 80 degrees F and the filters have been serviced and do another 30% water change. This should take care of any water quality problems. If the fish don't respond then I would remove them to a hospital tank were they can be observed more closely and look for symptoms.-Chuck> Thanks Chasel

Re: Attempt to save Ghost knife fish, II Hi,      Its was a typo on the food I feed them. I meant flake. But anyway, one of them is dead and the other one is laying on the floor now. I did another 30% water change, no use. I move the last one to another tank with and 80% fresh water no use either. Thanks anyway < Black ghosts like warm acidic water and usually don't eat flake food. If the water they were kept in was hard and alkaline then their kidneys may have failed due to an imbalance of  minerals in their system. Hard to tell. Sorry about your fish.-Chuck>

Feeding a Black Ghost Hello, <Hi back! MikeD here>     I am a very new aquarium owner.<Welcome to the wonderful world of fish addiction, er, keeping.**grin**>  I am obviously still learning about everything.<50 years later, me too. The learning never stops>  I just found your site yesterday and I'm loving it!!  But I do have a question regarding a black ghost knife that I bought about 3 days ago.  I currently have a 60 gal. tank with 2 parrot fish, 2 black skirted tetras <In the future tetras and often barbs, do better in schools of 5-6 rather than in pairs> 2 catfish, 2 angel, 2 Gourami, and now I just added the BGK.  Is this too crowded??<Not necessarily. My biggest concern is did you give you tank enough time to cycle, and/or that you added all, or most of your fish at one time.>  I am feeding pellets and flakes to the other fish, and got some frozen bloodworms and shrimp pellets for the BGK.<This may work, but some ghosties can be a little demanding on food choices, especially when they are first obtained>  I feed them around noon everyday.  I understand the BGK is shy<Not shy, nocturnal, which are two separate things entirely>, but he will not come out of his hiding spot when I feed the tank.  My other fish not only eat all the flakes and pellets, they also eat the bloodworms and pellets.  I'm afraid they are not leaving anything for the BGK.  Do I need to change my feeding time or habits??<Yes, the Black Ghosts are nocturnal nighttime animals that often are very reluctant to come out into the open during the day. Usually, this will gradually wear off in time, but early on the best thing to do is feed it separate, just after turning off the lights at night. You might also want to keep check and make sure that it's eating what you are offering for food.  The bloodworms will almost certainly be eaten, while the pellets are a big if for now, possibly forever.  They also relish raw shrimp (either cut up pieces of human food shrimp or the small live ghost shrimp sold as feeders in many shops) live or sometimes freeze dried Tubifex worms, daphnia, etc.. Their absolute favorite food is live earth worms like you'd use for fishing!  Some will gradually start consuming "normal" aquarium fare while most others are always somewhat demanding and require special foods>   Thank you for your help and information!!<You're welcome and I hope this helps...the Ghosts are one of my all time favorite freshwater fish species> Mike

Black Ghost Knife Help Hi there from another fishaholic!<Hi Jennifer, MikeD here> Sorry to bother you with petty questions that really don't apply to any of your other visitors, but I *really* need some help regarding my black ghost knife.<One of my all time favorite FW fish> Although I generally research fish species very thoroughly before purchasing them, I only did a little such research before buying a black ghost knife. It was really pretty much an impulse buy, though I was at least somewhat familiar with the species.<They're pretty tough if handled right> At any rate, the manager of my LFS promised me that if I purchased one, he would do just fine in a twenty-gallon, provided he had plenty of coverage and was kept completely by himself. She did say that it was pushing the limits to keep him in a 20-gallon, but that he'd do okay, even as an adult. (He's 7 inches now.)<I'm not sure why they told you to keep it alone, as they do well with many other species if the tank is arranged correctly. As to the adult part, my largest grew to about 15" if that tells you anything> Now, I'm starting to have second thoughts on that. I assume he's okay for *now* in the 20-gallon, but will he really be okay when he grows up? I have an extra 35-gallon that I haven't stocked yet but it's very well planted and decorated, as I tend to pride myself on that. The problem is, it's very hard, brackish water, and it would be a huge inconvenience to redesign and refill the whole thing. Besides, I was really looking forward to the archers and Sailfin mollies I was going to keep... But, if I need to, I'm willing to change conditions if that's what it takes to save my ghost knife. (I simply can't afford another large aquarium for him.)<OK. While he WILL eventually outgrow the 20 (20L or 20H?), they are fairly slow growers so you've got at least a couple of years before it should become a concern.> Wow, you're very patient if you're still reading this.<Still here **grin**> I guess, to get to my point, can my ghost knife stay in that 20-gallon as an adult, or even now? Or will I have to completely revamp the 35-gallon for him? Would a 35-gallon even be enough? Should I just swallow my pride and give that poor fish to somebody that can take better care of him? Just how fast will he grow, anyway? Maybe slow enough that he could stay in the 20-gallon until I could afford a new tank?<I guess I should have waited until I got here to answer, eh? **grin**> Also, the LFS lady told me that black ghost knives can be held and are even intelligent enough to recognize their handlers... is this true? Sounds a little odd...<It depends on what she means by held. If you cup your fingers in the water, they will indeed swim into your hand if you train them.  I don't know what you're currently feeding it, but they also appreciate meaty foods, with their favorite being earthworms. They'll also appreciate ghost shrimp and even a piece of raw shrimp like you'd have for dinner, unbattered, of course.  These are small cousins of the electric eel, and I'm assuming you know that they navigate by true electronic sonar. Because of this, never add another S. American Knifefish or African Mormyrids, such as "baby whales" or "elephantnoses"...they cross each others electric signals and a true war will result> Thank you SOOOOO much for your help! <You're very welcome>

Black Ghost Knife, yellow water, killing fishes I have a couple questions for you, I hope you take time in answering mine. I  see you do take a lot of care in the questions people ask. Here's one; I am wanting to buy a black ghost knife fish. Is this fish territorial? I  already have a loach in here and I don't want them to fight. <Likely will get along> Plus we don't want to buy pellets or freeze dried food, so will it survive on flakes? <No> My loach has been surviving for a couple months without those foods. <Won't be healthy on nothing but flakes forever> My second question is, my tank is getting yellowish color really fast and we clean our tank (55 gallon) like once every 2 months. What is up with that? <Need to do more frequent, partial water changes, maybe weekly... and possibly use carbon in your filter flow path> My final question is, my fish seem to be swelling up really badly, and then just die. I put in some medicine.  Is this what you call ich, if so what is it and how do I stop it? Thank you. <... time to study... and adapt a better maintenance schedule... It sounds like your system needs more regular care... likely your fish deaths are due to poor husbandry, a lack of nutrition, perhaps mis-medicating. Take a read over our website: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm re Set-Up, Knifefishes, Maintenance... IF you want to be successful at keeping an aquarium you need to learn more re what it takes to care for it. Bob Fenner> 
Black Ghost Knife
I read that a BGK likes tank temp.s up to 82 degrees. I've raised the temp. to help cure him of a series of illnesses and he's been in an 84-85 degree tank for about a month and a half now. How long can he tolerate the higher temperatures? <Indefinitely actually... will shorten lifespan a bit... but the only real worry here is aeration... dissolved oxygen is less soluble and metabolic rates elevated at higher temperatures...> I'm still treating him (with Paradigm for flukes, worms etc) so I wasn't planning on dropping the temp until this one hopefully goes away. Thanks so much for all your great info - you've been a really wonderful resource. <Glad to help. Bob Fenner>

Freshwater Question... Knife disease How long does it take for ich to kill fish? <Sometimes mere hours from the appearance of "spots", other times "never", the infestation existing as recycling generations...> I have a BG Knifefish and I thought it Had Gotten ich a couple of months after I got it. It has been 4 months that I see Some symptoms( green-like flour on him, yellow head stripe). When I got him his stripe was white I have raised the temp to 84, did many water changes and used medication at half strength. All water parameters are fine and the only other thing is that he is not that active from when I had him for the first 2 months( he is in a 30 gallon tank, about 5.5" long). His tank mates are a 3" Blue Gourami and a 4" Pictus cat( The cat showed symptoms but when I raised the temp. they disappeared). <They are VERY susceptible> I am Planning to move the 3 of them to a 55 gallon in the future (when should I get the 55 to move him into)? <Whenever you can afford it> What could this be ( Can you give me all the info you can)? <Perhaps "nothing" in the way of a biological disease... maybe another type of (internal) infestation... could be largely "untreatable"... If you have treated the system as you describe, I doubt if this is/was "ich"> Do BGK eat fish like angels, rams, Butterfly fish? Finally my friend wants to know, How many rams can you put in a 29 gallon tank? <This Knifefish does not consume any but the smallest of fishes... A twenty nine can house two pair of Microgeophagus. Bob Fenner> Jahner

Mainly Black Ghost Knife questions Hi and thank you WetWeb staff, My fish are doing great, after a very scary introduction. No one died and having been doing great (refer to suddenly stocked tank on WetWeb).  Well just a few questions, if I may.  But for reference I have a 55gal with Emperor 400, heater, etc., lots of (fake) plants, semi- fine (1/8" or smaller) substrate, a few rocks of different shapes making caves, heated to 80F, 7.8 PH, all levels great. a 8" BGK <Black Ghost Knife> a Pleco 6" 2- Blue Gourami (or Opaline Gourami not to sure because they have changed colors since I got the new one) a 4" and 2". a tiger barb 1.5" a clown loach 1.5"(just got him) a zebra loach 1.5" a ????? frog .75" I feed my fish a very wide variety of foods on a change by day basis.  My BGK has always been black and yellow I researched why because what I had seen was they should be white, I think on your site I was reading that some BGK are of a yellow variation. <Yes. this is so> Well my question is since I got mine a month and a half ago, he has started to turn whitish starting at the bands on his tail? I don't know why, I know that where he came from he was poorly fed and in a bad environment. Well Are there yellow variations or not (just mistreated BGK)? <The white/yellow markings do change with diet, water quality> My next question(s) is.  I now have 2 blue Gouramis how long will it be before they will reach sexual maturity?, <A few months> I know they're bubble nest builders but have never seen them do this. I have lots of plants. is it a comfort level or something? <In part... also, the motion in the waters surface, the presence of other fishes> they seem to be very happy, the most aggressive feeders in my tank (other than the BGK at night). what I'm getting at is if they will\can breed? <Doubtful, unless given a calm, warm setting... on their own> I cant find anything on sexing them so I don't know. <Search the Net, books... not hard to discern if of size, maturity> and at the same time can my loaches possibly breed? <Can, but rare... they do get BIG (a foot or so)...> They are inseparable.  I would also like to get 1 or 2 Bala sharks (I am going to be getting a new 125gal in September and plan a move) will they get along with what is in my tank? What else is a possibility for moving fish? Thank you all for the site and personal help, James <Yes, and many choices. Bob Fenner>

Black Ghost Knife fish feeding   8/30/07Hello there, <Greetings.> First I would like to say thank you for such an informative site. I have been using it for quite a while now. <Glad you're enjoying.> I have 2 Black Ghost Knife fish (in separate tanks) they are both about 7 inches long. Right now their diet consists of raw shrimp, earthworms and frozen bloodworms. I would like to expand on that to give them the best , safest diet possible. One guy at our LFS recommended raw beef hamburger. Have you ever fed yours that ? Is it a safe alternative ? I live in an area where our options for frozen food are limited. <Raw beef is not even remotely a safe or sensible foodstuff for a BGK (Apteronotus albifrons). Wild fish feed almost exclusively on small invertebrates, specifically worm/insect larvae type things and small crustaceans such as Daphnia. They don't really eat fishes, let alone meaty foods. So, with that in mind, your existing diet sounds just about ideal, so why not stick with that? Treat them to some live daphnia or brine shrimp when you get the chance, or "grow your own" midge larvae in the garden if you can. But otherwise, stick with what you're doing. There's a specific problem with feeding beef to fish, and that's the fact fish are cold blooded. Warm blooded animals use lipids that are oils at (warm) body temperature, so flow, but become fats (i.e., solid) at lower temperature. In short, feeding meat from warm blooded animals to fish is, with a few exceptions, an invitation to clog up their digestive systems and circulatory systems. Not good. Beef heart is sometimes used to feed fish because, being cardiac muscle, it doesn't contain any fat or oil. But other types of meat, especially muscle meats, are just NOT SAFE.> Thank you for any help or suggestions you may have to take care of our beautiful ghosts. They are a joy to own and raise. Sincerely, Rebecca <Cheers, Neale>

Black Ghost Knife fish pairs?  8/13/07 I just discovered your website, and it is wonderful!! I've found so much info on BGKs! It has been very helpful. <Ah, good> I do have a quick question. My husband and I bought a BGK about a month ago (Oscar), and he's been doing great! I had read in a fish forum about getting more than one. Several people claimed they had a pair, and they got along great and seemed to enjoy having another "friend" like them around. <Mmm, the exception actually... most Apteronotids fight in small confines> So, today we bought another BGK (Fritz). Though Oscar hasn't actually damaged Fritz or harmed him in any way, his behavior has been aggressive towards him. (Periodically, Oscar darts at him and chases him for short distances.) Fritz respects Oscars space and goes the other direction, but he doesn't seem to be overly concerned with Oscars behavior; he doesn't hide from him (he's been busy exploring his new home); and he doesn't return the aggressive behavior. He simply starts swimming the other way, and generally Oscar doesn't pursue him for long. My question is Oscar, our veteran, eventually get used to Fritz (newcomer), or do we need to separate them now before any real damage occurs/their own health and happiness? <I see the pertinent info below> Oh, they live in a 29 gallon (long) tank for now. <This is too small a world for these two> Oscar is a little bigger than Fritz (approx. 3-4"); Fritz is the same size Oscar was when we bought him a month or so ago. We are cycling a 55 gallon tank before we add any fish. <Good> Both of them have eaten well since Fritz arrived. Fritz acts totally normal besides being a little more active than usual, which I'm guessing is due to his new home. It's Oscar that all freaked out. Thank you!!! Kim <I would move one of the Knives to the new tank once it's ready... and maybe try re-acquainting them there in time. Cheers, Bob Fenner>

Sick Black Ghost Knife  08/01/07 Hello, <Hi, Pufferpunk here> First I'd like to thank you for having so much helpful information on your website. <You're welcome!> Now, I have had my BGK about 2 weeks now and I believe he's quite sick. His body is covered in a white film [which at first I thought was due to the sand I have] but it's been getting worse lately and just a moment ago, I noticed the white area on his tail is turning red. I read some information on your website, which advised me to do a water change, and increase the temperature. So I did a 25% change, and got the temperature to about 80. The white film cleared up almost immediately. [I believe this was due to the nitrite being very high prior to the water change]. Now today, the white film appeared even worse. I did another water change, around 35% this time, and added some nitrite and nitrate removing chemical. I do not know what to do, and I really don't want to lose him any time soon. I'm hoping you can help, and thanks so much in advance. <If your tank is showing nitrates, then it isn't cycled properly. It is difficult to help without knowing more about your tank. Ammonia & nitrites should be 0 at all times. Nitrates need to be kept below 20. The only way to reduce nitrates is with water changes. The fact that the fish looked better after a water change, tells me that this is a water quality issue. It would also help me to know, how long the tank has been set up, was it cycled properly before you added the fish, how large is the tank/fish & what tank mates are in there with it? Please let me know all this & write back. In the meantime, do another 50% water change, add Melafix & 1 tbsp aquarium salt/10g. ~PP>

Was: BGK/Cycling a Tank/Dyed Fish 8/2/07 Thank you so much for such a speedy response, it means so much. To answer your questions; The tank I have him in is only a 10 (I know he will grow out of this very quickly but he'll only be in it a couple more days.) I figured this was okay as when I got him he was no more than an inch big. He shares the tank with two "painted" tetras that got put in there a day after I set the tank up. They did fine, so I a day later I put the BGK in. Unfortunately, I was told 24 hours was all it took to cycle a tank [And I work at a fish store ;\ ] After setting up the tank and reading some information on your website, I realize I should've let it run for at least 2 weeks. <Please read much more on cycling tanks. You could let a tank run empty for a year & it wouldn't cycle. Find out more about the bacteria needed to break down ammonia to nitrites, then to nitrates, which much be removed by weekly water changes. This entire process can take 2 weeks, if "fishless cycling" & up to 6 weeks if cycling with fish (bad idea--stressful to the fish). All this info is on our site. For an instant cycle you can use Bio-Spira. I recommend you use this to cycle your larger tank immediately. You owe this to your customers to know all this. Please urge your manager/owner not to carry dyed fish! See: http://www.deathbydyeing.org/ (can't seem to get that site to work but excellent info there), http://en.wikipedia.org/wiki/Painted_fish http://www.practicalfishkeeping.co.uk/pfk/pages/campaign.php  Just do a search on "dyed fish" & you'll find countless arguments against it. I will not buy from any store that carries them.> But I have kept that in mind as the BGK's new home, a 29 gallon [and not permanent] home is being cycled as we speak. <Check into the adult size of your fish. You will eventually need a minimum of a 90g tank. You owe it to your customers (& the fish) to know the adult sizes of all the fish you sell & the minimum tank size for an adult. You are aware this fish won't eat flake food? My 15" fellow only eats live blackworms.> Anyway, as soon as I got your e-mail I ran out and got both the Melafix and aquarium salt. So I'm hoping by tomorrow, he will clear up a bit. Again, thank you for your helpful response, and your time, I appreciate it very much. <I suggest daily 50-80% water changes, until you can upgrade him to a cycled tank. ~PP>  

Black Ghost Hey MacL thanks for such a prompt reply. Sorry I didn't realize that I hadn't given you enough info. Its a black ghost knife (Apteronotus albifrons) fish. <Lovely fish, just lovely.> I've got him in a 200L tank at the moment and he is about 11 inches long but I really really want him to get BIG. Please let me know what the best thing I could do to increase his size. <Good food, clean water. And some time should do the trick for you. I think you are on the right path.> Thanks again Guru

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