FAQs About Koi Kept in Aquariums
Related Articles: Goldfish, Goldfish Varieties, Goldfish
Systems, Goldfish Disease,
Scaredy cat Koi
I have two Koi in an indoor 55 gallon tank,
<Will need, or may require more room right now>
they have been in this tank for almost two years now and they are doing great
and thriving and growing. But they still scatter and panic when someone
walks into the kitchen where the tank is kept, hitting the rocks and glass walls
of the tank beating their beautiful heads off, but no injuries yet ; )
<Uh, yes there are>
Any advise would be grateful...
Mr. John C. Hanna
<A much larger system or a move to a sizable pond. Bob Fenner>
RE: Scaredy cat Koi
Well thank you for not answering my question! I live on a river and have a Great
Blue Hereon problem they ate all the Shubunkin fish but left the Koi
<Ah yes; Herons can be very hard to guard against>
so I brought them in I love my fish and was devastated at the loss and did not
want to leave the others to the same fate...
<Mmm, perhaps reading on WWM ahead of writing; as we direct folks...
There are anti-depredation techniques to consider>
You know you all had several rules on sending in an e-mail I know that there are
people out there that do that kind of stuff,
I do not feel that the "between the lines comments" are necessary. And if I
where your Supervisor you would be fired!
<We have no supervisors, and are all volunteers. Perhaps my pond books (see
Amazon) are more your speed>
Once again thank you for your courteous answer.
John C. Hanna
Customer Service Supervisor
Mr. Suds Inc.
<Read John; don't hate. BobF>
Hi; Nishikigoi in sm. aq.s 9/1/13
I just bought an Aqueon 15 column aquarium and have 5 small koi's
in there and I don't know nothing about fish plz help.
<Umm, really? Is this system cycled? Koi can't live in such a volume...
Please read here:
hi (Koi and Iridescent Sharks in 55 gallons… can I add an
Oscar?) Wacky FW mixes
hi, First of all let me tell you that you are running a great site. Lots
of useful information. Thanks a lot .
<And thank you for the kind words.>
Now about my issue. I already have a 55 gallon tank.
<A great size for an aquarium!>
I have a 5 inch & 2.5 inch Koi,
<Whoa! Not in this tank for long… Do bear in mind that a
healthy Koi will get to around 2 ft/60 cm, and they're sociable animals
too, so keeping in an aquarium isn't really viable.>
two 3.5 iridescent sharks
<Same again! These get massive, potentially over 2 ft/60 cm
even under aquarium conditions, and something like twice that size in
the wild. Most aquarium specimens die long, LONG before that because
they can't be kept properly in home aquaria.>
& one 5 inch Pleco.
<Do-able, but will make the tank filthy; would always favour a smaller
Loricariid catfish in 55 gallon and smaller tanks, e.g., an Ancistrus or
for the more ambitious, something like the Green Phantom (Baryancistrus
demantoides) which gets to around 15-20 cm/6-8 inches.>
Is my tank already overcrowded???
I want to add two 2 inch albino red Oscar. Is it a wrong move?
Oscar will be too aggressive to other tank mates???
<Not as such, no. Oscars are not aggressive fish outside of spawning,
and actually work well with large barbs (e.g., Tinfoils and Spanners)
and L-number catfish. But a single Oscar will fully occupy a 55-gallon
system in terms of filtration, water quality and water changes -- even
adding a catfish will make it VERY HARD for you to keep the water
quality right, especially in terms of nitrate.>
If Oscar is not a good choice then can you give me few good choices???
<I would start over with this aquarium entirely. Have a look at a
peaceful, medium-sized cichlid like the Blue Acara or Firemouth if you
want a mixed species set up, then choose companion species of
appropriate size to go along with it. Firemouths for example work well
with Swordtails, while Blue Acara could be kept with medium-sized tetras
such as Bleeding Hearts or even Rainbowfish if you don't mind a "non
South American" mixture. Both would get along well with L-number
catfishes in the 10-20 cm size range. If you just want cichlids, then
Tanganyikans are especially nice cichlids to keep, with numerous
Lamprologus and Julidochromis species being just the right size to fit
into a tank like this.>
My Other issue: I'm planning to buy a 22-24 gallon tank. This one will
be a planted aquarium. I'm planning to add neon tetras. How many tetras
will be enough in this tank???
<Neons do best in large groups, and this tank is easily big enough for
12-14, and that would still leave space for one or two other small
species, perhaps 3-4 Corydoras and a single specimen fish like a Dwarf
I'm thinking about adding full red guppies & full black guppies. Is it a
<With Neons? It's doable, but Neons do need fairly cool (22-24 C/72-75 F
is ideal) water that's soft and acidic (certainly no harder than 15
degrees dH). Kept otherwise they are alarmingly difficult to keep alive
for more than a few months, especially the cheap, disease-prone farmed
ones sold in most pet stores. Guppies are equally disease-prone and
farming has done them no favours at all, so again, you're fighting with
one hand behind your back if you try to keep them in less than perfect
conditions. If this was me, and I wanted to keep Neons, I'd tailor the
tank around their needs as described above, and if Guppies, I'd want a
hard, alkaline system with the definite option of adding a little salt,
which rules Neons right out. Thirty years ago both Neons and Guppies
were quite hardy fish, but that isn't true any more, so I'd treat both
species as "demanding" fish that need a little molly-coddling.>
What's your suggestions for a 24 gallon tank???. Please suggest fishes
which don't try to uproot my plants.
<Assuming your water is neither too hard nor too soft, so around 5-15
degrees dH, pH 6.5-7.5, then my favourite hardy and commonly sold fish
for planted communities include Cherry Barbs, Dwarf Rainbowfish, X-Ray
Tetras, "False" Penguin Tetras, Emperor Tetras, Bronze and Peppered
Corydoras, Bristlenose Plecs and Whiptail Catfish. None of these will be
hard to keep and all thrive across a broad range of water chemistry and
temperature values. Danios can also be excellent, but in small groups (6
or fewer) they sometimes become aggressive, so approach with caution. Of
the commonly sold livebearers, Platies are about the least troublesome,
but remember they must have hard water to do well and will be sickly if
the pH is below 7. Swordtails and Mollies need more space than you can
provide, and are demanding in other ways too. If this was my tank, I'd
probably go with Cherry Barbs for midwater colour and activity, a school
of Corydoras for the bottom of the tank, and maybe Leopard Danios for
the top of the tank.>
Thanks a lot for reading my mail. Please reply. bye
<Most welcome, Neale.>
Koi carp, infected scales? 12/28/12
I needed your help regarding the condition of my carp. As you can see in
the picture the scales are popping out and they are bleeding probably.
<Perhaps Carp Viremia; though bacteria, simple mechanical injury might
account for this appearance, the one only being affected>
The other carp is fine. The affected carp is also showing normal
behaviour but since there are no improvements, so I thought it would be
better to consult
you. The capacity of the tank is 180 litres,
temperature is around 25 degree Celsius, and other inhabitants
excluding the carps are two turtles.
<Poor tankmates... see WWM re... the search tool on every page>
This happened a few weeks ago and I do not know what should be done.
<Improved water quality (removal of turtles esp.), and nutrition (I
suggest Spectrum pelleted...) are the only (indirect) methods of
"treatment" of use here. No direct. Bob Fenner>
Questions on how to properly house Koi fry until my pond is
I have recently moved from Virginia to Florida, and had acquired 14 Koi
fry right before my move.
<Fry? How small>
They made the 14 hour trip in the moving van just fine (I was scared to
transport them, but stuck an air stone in the bag that was on the whole
trip and they made it!). I have since put them into a 10 gallon aquarium
until I get my pond designed and built here at the new house. I have not
had good luck lately, in the past week 2 of my babies have died, oddly
enough they were 2 that I considered to be the strongest and fastest
growing of the bunch. All are under ¾" long. I have one that is stunted
- the same size as when I got him in the middle of June. There is also 1
small Cory cat in the tank to help with cleanup. =)
<Should be fine... do know BTW, that fishes period, cooler water species
more so, often have a lag time in showing stress... dying days after an
I have had problems with the tank being cloudy, even while doing daily
40% water changes. The nitrites and ammonia were pretty bad for about a
week, but are now finally getting under control. Here are the readings
Nitrate - 0
Nitrite - .5
<Needs to be 0.0>
Hardness is at 0 - we have a water softener system on the house... I
don't know how to fix this (?)
Alkalinity - 300
PH - 3.4
<No... please check again... needs to be neutral to slightly alkaline...
7-8 or so>
My questions are:
Should I get a preformed "water garden" container for them instead of
<A ten gallon should be fine for a couple, three months... w/ moderate
feeding, regular (small percentage... 10-20%) water changes>
The filter just doesn't seem to be cutting it to me. On that note, how
can I find a filter for one of these container gardens that will not
suck my babies up?
<Look into a sponge type>
If they are in a larger container garden, do they actually need a
filter, or just plants and air?
<Koi need a 24/7 filter, water movement>
The guy I got them from did NOT have a filter in place.
Should I keep them where they are, and if so, can you suggest ways to
fix the problems with my water? Maybe upgrading to a much better filter?
<Yes to the better filter, an additional one>
I am feeding them twice daily (they are little piggies usually - but not
so much as when I first got them) Omega One Natural Protein Formula
Super Color Flakes for tropical fish
<Need lower protein... less than 20%... pellets are better than flakes>
as I cannot find a food specifically for Koi that is small enough for
them to eat. I crush the flakes before feeding. Any suggestions here
would be greatly appreciated.
The last baby that died had blood in his eyes...
<Likely the ammonia and/or nitrite>
yesterday he swam listlessly for about 30 seconds and then was fine. I
thought maybe he hit his head on the tank. One other baby had done this
a few days ago, but he is fine. He did not have the blood in his eyes
while he was alive.
Thanks so much in advance for your comments/suggestions!
<Welcome. Bob Fenner>
Re: Questions on how to properly house Koi fry until my pond
is built 8/14/12
Hi Bob =)
Last I wrote I was having issues with pretty much everything. I am
happy to report no more casualties, both nitrates and nitrites are at 0,
Hardness is now "hard" instead of soft, PH is 8.4. I have changed
their food to a floating stick that softens... they love it. It
had the lowest protein formula I could find, at 28%.
I've upgraded the filter - and the water is spectacular. I bought
a plant for the piggies to munch on.
Now one of the babies has what appears to be ick on his tail.
<Don't panic! And don't treat... if one "dot", not Ich, nor likely
parasitic... most likely just a physical "bump">
I'm not quite sure he could get this from a plant, but I have no other
idea where it could've came from.
Should I pull him out?
Should I treat the whole tank (and if so, any suggestions would be much
Thank you in advance for all of your wonderful help! You guys are
(PS - you will get a bounce back email that I don't exist... I assure
you I do. =) )
Re: Questions on how to properly house Koi fry until my pond is built
Wow that was a quick response! I just wanted to make sure - don't
add any salt or anything to the aquarium?
After staring at my little guys tail for awhile - it appears to have a
moldy type look to it... its probably the size of a pin head - but the
fish isn’t that big ;) It looks raised when looking at him
from an angle.
I just don't want my babies to die.
Thank you for all your help!
Koi with bulging eyes and bent tail
PLEASE HELP. I have had my Koi Sol for about 5 years with 2 other Koi
that have never been sick. About a year ago Sol developed some
sores that after treated with antibiotic food would usually go away, but
then they kept coming back in different places.
<Mmm, the pandemic, Ana aki, Furunculosis... see WWM re>
They were in a 10 gallon
<Way too small a volume>
till the sores appeared so i moved them about 6 months ago to a 30 gallon
and a new filter which doesn't seem to work.
Sol has gotten sores ever since the move. Sols eyes started bulging
probably a year ago nothing i do gets them down, after the antibiotic
treatments for the sores the eye swelling goes down but never goes away.
I recently added zeolite to the filter because i couldn't
control the ammonia
and was told that was why he was getting the sores. Now
about a week ago his tail started floating up, and each day it got
worse. Yesterday he was upside down, so I treated with QuickCure
and salt which worked years back when he had swim bladder issues.
<All these issues are environmental in origin/cause... Fix the env.>
Now he's right side up but has trouble swimming and his tail keeps moving
up, it looks like something is pulling him up from the tail and it
starts bending at the anal fin. I have had so much trouble trying
to find out what is wrong, everyone tells me check the water, but the
water seems okay and the other two fish have never been bothered AT ALL.
Sol started laying at the bottom a couple of weeks ago but every time I
came in the room he would swim up and get excited, and whenever he knew
i was there he would swim around.
During all of this he has still eaten and swam normally until yesterday,
what else would cause the tail to bend up and cause him to float like
He has been dealing with these problems for a while now and has not shown
any signs of lethargy or as if anything were wrong until recently.
Sol has a very strong will to live and he is very happy and excited to
see me even though he can hardly swim. I need to know what i can
do to help him get better because i know he will if i just knew what was
wrong. thank you.
<All these issues are environmental in origin/cause... Fix the env.>
<... read here:
Re: Koi with bulging eyes and bent tail 6/19/12
is zeolite harmful to Koi?
There are no nitrites and nitrates and almost no ammonia.
<Any ammonia is... have you read where you were referred?>
You're telling me that he has been having sores and bulging eyes for a
year because of the environment while the other two have never EVER had
anything wrong. How do I fix the environment and why is his tail
<More, better filtration>
He also gets what look like blisters under the skin. I cannot put
them in a larger tank it is impossible to do appropriate weekly water
changes in anything larger. If doing weekly water changes and
keeping the ammonia down were the problem he would not be sick from
these things. How can he be sick off and on for a year and not get
better if it was ammonia. Please Help. There is gravel at
the bottom what is a better alternative?
<... Please read, don't write till you have. B>
I really need help with this one. I have two very small Koi, a butterfly
Koi and a regular Koi. They're both only about 2 inches long, and for
now i have them in a 10 gallon tank. I know its fairly small for these
kind of fish, but it has to do for now until I can clear the room to get
a larger tank in here. Anyways, when i introduced the butterfly Koi,
they got along perfectly fine for a few days. But lately, the original
one in the tank has been pushing and bumping into the butterfly. The
butterfly doesn't do much about it, just swims away after a few bumps,
but sometimes the other Koi will chase the poor thing around the tank.
Also, I believe there was an ammonia problem in the tank as
<Trouble... and likely related to the misbehavior. There must be 0.0
I did a test and have been treating the water with ammonia eliminator
<Of no real use... need sufficient bio-filtration>
The fish are no longer showing signs of sickness, but the original tank
dweller is still bullying the butterfly Koi. I've tried separating them
a few days and reintroducing after moving the objects in the tank
around. It seemed to work for about a day, but then the bullying
continued. The fish are pretty much the same in size, and the bullying
hasn't left any damage to fins or scales. The only difference in size is
that the butterfly is slightly more slender and the other one is more
bass-shaped. Any advice will be greatly appreciated! Do you believe its
an issue with space, or territories? I'm hoping its something more
<... water quality mostly. Bob Fenner>
Koi with red lump/sore on side of
Hi I have an at least 4 year old Koi about 4 inches long
in a 10 gallon tank with 2 other small Koi,
<Need much more room than this>
they have lived together for years and i had one more until about 4
months ago, when he suddenly died. My problem now is that i
recently moved them about 4 months ago after the Koi died and cleaned
the tank and rocks and filter, then a few weeks ago i noticed a
terrible film on the top of the water, so I cleaned the filter and
there was thick greenish brown muck clogging everything and little
black things. Then i replaced the carbon and filter pads, and the
film was still there. I thought maybe they had spawned because
the small one kept brushing on the larger ones, but they are only 4
inches long tops. So the other day I noticed a lump on my
koi's side, which only looked like a small bump with no
discoloration or redness, so i watched it and the next day it was
larger and red. As the day progressed it got even larger and very
red and bloody with a small vein next to it. I looked everywhere
for solutions, so i treated them with tetracycline for 4 days
<Of no use>
and did the recommended water changes, and siphoned the
gravel. During the treatment the redness went away but the lump
was still there, and the day after the treatment was done the redness
immediately came back like i didn't treat it at all. I need
to know what parasite to treat for, or what is going on, there seems to
be no answer for this anywhere. It looks like a giant pimple on
his side, with a white thing in the middle, and a large lump
underneath, it is the only one so far and no one is acting different,
they want more food as usual. Please help this is my oldest Koi, and I
love them very much.
<Please read here: http://www.wetwebmedia.com/FWSubWebIndex/koiaqfs.htm
The only way to improve and lengthen the lives of these fish is to get
them into a bigger and better environment. Bob Fenner>
Koi tank 12/14/11
I have a 10 gallon Koi tank.
<... there is no such thing... Akin to a closet dream
Normally it has 2 small Koi in it 3-5 inches long. Last
year one of them died
i don't remember the specifics cause sometimes they just die
and the other remained healthy.
<Stop. Read here: http://www.wetwebmedia.com/FWSubWebIndex/koiaqfs.htm
Good bye Bob Fenner>
This summer I bought another small Koi to put in with it.
The next day the new Koi started floating head down along the bottom of
within 2 days it was dead. The store replaced it and then the one
which i had over a year started to do the same thing and died. I
went back to the store and the 2 suggestions that I received were that
it might need more aeration the other was build up of nitrogen. I
thoroughly cleaned out the gravel and purchased an air pump besides the
filter. The remaining fish seemed ok although it never really was
an active swimmer and remained at the bottom of the tank. Now in
December, yesterday i saw it doing the same
thing as the other two had. It stops swimming along the bottom
and the tail end just floats up like it is doing a headstand. Is
this a swim bladder disease problem or something else? every site
i go to talks about goldfish and not Koi. And i haven't come
across any that refer to floating at the bottom of a tank.
I am new to your site but not new to fish. I have grown up with all
kinds but I've stumbled upon a problem that I just can't
solve. My fiancÃ© and I have a 150 gallon indoor tank.
We have 2 Koi, 2 Plecos, 2 Oscars (they don't mess with
anything as everything else is bigger for now), a parrot fish,
and 2 map turtles.
<Mmm... too much and dissimilar environments needed here to
keep all together... The Koi need cooler and larger waters,
the Map Turtles are too ]dirty... the cichlids and Pleco can live
Now my black Koi is the one with the problem the other orange and white
is perfectly fine they are both roughly 8 to 10 inches in length. Lets
start with a little back ground, we had a few more Koi awhile ago and
we had a terrible ammonia spike that killed out biggest Koi friend and
the butterfly Koi.
<See my notes above>
The black one and orange were there then to but they survived.
Everything has been taken care of and we monitor the levels very close
now (which are all pristine). For some reason the black Koi still swims
to eat and sometimes messes with the gravel like normal but it always
returns to laying on the bottom.
<This type of Nishikigoi is close/r to the wild type
It's kind of like it gives up after a few seconds if there is
no food. It doesn't have any sort of labored breathing the only
noticeable thing is it's missing a few scales because we used to
have a gourami in the tank (who is now moved). Like I said earlier
nothing messes with it and the orange one tries to make it swim by
swimming around it, it only works sometimes. The black Koi was our
second Koi ever and I don't know what to do.
<Plan, dig a pond...>
I'd hate to see it gone. The filtration is great and aeration too.
It has been set up for almost a full year now but it's only been a
couple of months since the ammonia incident. Any advise is greatly
appreciated, we love to watch them and so does our Chihuahua.
Thank you for your time,
<Do consider what you're about here. What you have is an
untenable mix of life crowded into too small a world... Bob
Japanese Koi URGENT 3/12/11
Good Evening, Ethan Ong from Thailand. I raise Japanese Koi in a tank.
Last Saturday, one of the Koi accidentally suck by my water pump on it
<Unusual... healthy Koi almost always avoid such>
It did survive and yesterday I saw the skin come out thinking that the
new skin coming out. This afternoon I catch it to have a look. I can
saw the flesh but no new skin. The fish is still active and eating
food. Will the skin grow back? My fish is just 7-8 inch only.
<Hopefully so; and generally yes, if there is not "too
much" damage... Do provide extra care in water quality and
nutrition. Bob Fenner>
Re: Japanese Koi URGENT 3/13/11
Hi Bob Fenner.
I'm using Tetra Pond MediFin
The wound is as big as 1 inch. Very sad to see it. Will this products
work for it?
Should I separate it? Do I need to remove the skin that still hang on
<I would leave this fish in place (DO cover/screen that pump
intake!) and leave the skin in place as well. BobF>
Re: Japanese Koi URGENT 2/13/11
Hi Bob Fenner,
Thanks. Your reply make my worry less, I care for every life of my
God bless you.
Koi Help (RMF, any tips on Koi indoors?) <<Not here,
no. RMF>> 10/17/10
I have 3 Koi in a 75 gallon tank.
<There's your problem. Koi do extremely bad in aquaria, and 75
gallons really isn't viable. Even 200 gallons would be barely
Last year one of the fish developed Fin Rot and a Cotton Growth at the
sides of its mouth. For the last year I have treated with Melafix and
numerous treatments with Kanaplex. Seachem told me it would not
overdose the other fish and should resolve the problem.
<Indeed, these medications should be safe, but because environmental
conditions are wrong, medicating these fish will be a perpetual thing.
It's like giving someone contaminated water to drink every day.
antibiotics would cure the disease of the week, but darn sure
they'll be sick again before long.>
At one point the mouth seemed to clear up. My Koi has reached the point
that most of the fin is missing on one side and the mouth area is
So far, the fish is still active and eats. My tank is cleaned by a
company every 3 weeks, at which time the water is always tested. I know
the water conditions are good.
<Really isn't. Even if ammonia and nitrite levels are zero,
which I doubt, nitrate levels will be high, and oxygen content will be
low. Plus, between water changes there will be pH drops that are
suddenly put right every three weeks.>
I love this fish and am in a real panic at this point for fear the rot
will reach the body, plus the area around the mouth is sticking out
Please help me in saving my fish.
<Alice, honestly, this isn't going to work; I don't know who
told you Koi can be kept in 75 gallons, but they sold you a bill of
goods there. Yes, Koi are amazing fish, and yes, they do become truly
tame, even friendly, in a way few other fish do. But they are pond
fish, and they have been bred for pond conditions across hundreds of
years. Some of the Goldfish are good choices for indoor aquaria, but
unless we're talking about an indoor pond, Koi really aren't an
option. Cheers, Neale.>
Re: Koi Help (RMF, any tips on Koi indoors?)
Thank you for your response.
The reason I have the 3 Koi in an aquarium is because my husband died 4
years ago, and at that time I lived in a much larger home and we had
over a hundred Koi in 3 large ponds.
It broke my heart to give them away when I moved, and I couldn't
part with the last 3 that he bought.
<I fully understand and sympathise.>
I realize they belong in a pond, but no longer live where that is
The other 2 are fine and I truly want to try and make the Koi I have
discussed well. Are you sure there is no way to accomplish this. Any
suggestion would be greatly appreciated.
<In the short term, yes, antibiotics will treat Finrot (raggedy
fins, sore/bloody patches on the body), and anti-fungal medications
will treat Fungus (cotton wool threads). But if the environment
healthy, it won't be long before these fish get sick again, with
genetics perhaps playing a role too, the "weakest" fish being
the one that gets sick first. A larger filter will make this aquarium
more viable for longer, so adding a very large external canister filter
for example might be an option. But three Koi in 75 gallons is never
going to be easy. I'm sure your husband told you enough times that
Koi are princes among fish, and need to be treated like the royalty
they are. They're very special, very intelligent, and very
long-lived animals. Yes, they thrive on love, which is one reason we
like keeping them, but they also need the right living
I have 3 aquariums in my home, the other 2 having small goldfish. When
I have a problem with 1, I always look at your answers to others
pertaining to whatever problem a fish may have. I have learned a lot
from your website.
<I'm glad we've been able to help.>
Hopefully, you can offer a solution for me. I truly want to keep the
<Here's an alternative. Try and find a fish or Koi club in your
city. Zoos and botanical gardens might be worthwhile too, as these
often have Koi pools. It may well be that you can find an experienced
Koi-keeper who can come take these fish and give them a more
comfortable retirement. One way of looking at the situation is to see
these animals your husband loves, but for one reason or another,
aren't enjoying their life. It's much the kindest thing, and
perhaps the more honourable thing, to rehome these fish someplace nice.
In the meantime, you say you have someone fixing up the tank every
three weeks. Feel free to pass on our e-mail address to them, and they
can discuss their ideas with us if needs be.>
<Hope this helps. Cheers, Neale.>
Koi Not Eating and Sitting on Bottom (Fenner-san, any Koi
wisdom to share here?)<<Nada>>
I have the following situation:
125 gallon aquarium
2 Eheim Pro II Canister Filters
Water quality checks out normal
5 Koi living in the same tank for 3 years. No additional plants or
<Well, you should at least be adding pond plants that your Koi can
eat; these fish are herbivores, and a strict diet of pellets
doesn't do them much good. In ponds they'll be eating algae and
sifting organic detritus, so it's less of an issue. In aquaria, you
really need to watch this aspect.>
4 Koi are active and eating just fine.
5th Koi which is very fat is not eating and sitting on the bottom. It
started about 2 days ago. No visual signs of disease, with the
exception of fins being clamped and it seems like it requires effort to
swim up from the bottom. The anus/vent region also appears to be larger
then normal. Is it possible the fish is constipated or egg bound which
would cause this behavior?
<Constipation could certainly be an issue. Read here:
Any thoughts would be appreciated.
<More generally, a 125-gallon tank is insanely small for Koi.
Let's be crystal clear about the fact Koi do poorly in aquaria
anyway. They don't even do well in small ponds! So unless your
aquarium is 500 gallons upwards, Koi are not going to be easy to keep,
if viable at all. So general issues with improper housing could very
easily be to blame here -- non-zero nitrite/ammonia levels, nitrate
levels above 20 mg/l, insufficient space for exercising, and so on.
I'm not a huge fan of keeping Koi or Standard Goldfish in aquaria,
to be honest. Cheers, Neale.>
baby Koi 9/7/10
I'm hoping you can help me I have a 10ft pond with Koi I have just
starting in the Koi side, a few months ago I got some baby Koi
3-4" and put them in my pond, time went on and things were ok
suddenly one day they died day by day and was left with one, I brought
a fish tank as well as some other baby Koi and put them in since
putting the small Koi in the tank they are swimming around like mad
they are in a 2ft long by 1 Â½ foot tall tank there is plenty
of room ( I think) roughly 9 of them the temperature is between 20
ï¿½ 22c it has a sponge filter
<Mmm, not likely able to "keep up" with metabolite
production here. Do monitor ammonia, nitrite...>
and a air stone in there they are feeding ok on crushed up tetra pond
sticks but like I say they are swimming like mad is this normal as I
don't really want to lose these ones I look forward to your
<? Re? Please read here: http://wetwebmedia.com/PondSubWebIndex/pdenvdisdiagf.htm
and the linked files above. Bob Fenner>
Just a few questions'¦ (Bob, thoughts on Koi
<<Can work, given space, good water quality as you relate... but
not long term in aquariums. RMF>>
As you can see from the subject I have a few questions that I'd
like to throw into one email to prevent my from bugging you later on :)
I did some searching with the Google thing at the bottom of the pages
but only found
the answer to one of them (the questions).
First off here's some info on the tank. It's a 250 US gallon
monster (freshwater) with 2 canister filters and 2 powerheads. I did a
50% water change yesterday and forgot to test afterwards but the pH
beforehand was 8.4 (I don't know if I should lower it as all the
goldfish seem pretty happy).
<Sounds fine. The tank is big and Goldfish like alkaline water, as
do many other kinds of fish. Hard, alkaline water is actually very good
for fishkeeping, provided the fish you choose enjoy it.>
Nitrate was about 20ppm and nitrite was at .5ppm.
<This nitrite level is not good, and potentially stressful in the
long term. Either the filters aren't mature, they're not
properly maintained, the tank is overstocked, or you're
overfeeding. Possibly a combination.>
The test kit also tested hardness and alkalinity which I have written
down somewhere but the paper isn't very easily accessible (not in
this building). It's inhabitants are: 4 "feeder"
goldfish, 4 large common goldfish, 2 Koi, 2 Orandas, 1 Shubunkin, 1
fantail and 2 Plecos all of which I have had for roughly 2 months
except for one of the Plecos which I have had for 1 month.
<That's a lot of potentially very big fish. You don't
mention their size.
Ultimately, even 2 adult Koi could overwhelm a tank this size.>
My first question is will my Koi outgrow this tank when they (and all
the other fish) get to be full size?
<Yes, they will. Koi are not really indoor fish. For Goldfish, allow
20 gallons for the first specimen and another 10 gallons for each
subsequent specimen. You have 12 specimens, so that's 20 + 10x11 =
130 gallons for the
lot. Another 20 gallons for each Plec, that's 170 gallons if
we're being generous, and over 200 gallons for the lot if we're
realistic. Without the Koi, you should be okay, but honestly, with the
two adult Koi, I think you'll be pushing your luck.>
If they will then I'd like to get rid of one or both while they can
still be netted. They've grown 1" maybe more since I first got
them 2 months ago and eat like little pigs. I tried searching this one
but all it brought up was some info on Koi breeding, Koi outgrowing 55
gallon tanks, and kinked backs.
<Indeed. Koi just don't do well indoors. They've been
domesticated for hundreds of years as pond fish, and that's what
Second, I read some info on Plecos from your site (maybe?) and
discovered that keeping 2 Plecos in one tank is a really, really bad
<Yes, or at least, two males can be extremely aggressive, and males
attacking females is not unknown.>
If this is true than I'd also like to get rid of one while
they're still somewhat small and there's still jars and bags
big enough for them to fit into (3" and 6").
<Sometimes they get along fine, and in the wild they are schooling
fish. So for now, watch and observe. But if you see signs of
threatening behaviour, or worse, damage to one another's fins or
body, then separate them. There
are reliable stories of Plecs killing one another if they're forced
together as sexually mature adults.>
Third, my Plecos seem to be eating the paint off of 2 of my
<Yep. Doesn't seem to do any harm, but is annoying.>
The paint is gone in patches on one of them and on raised areas that
they can get to on the other one (fake tree). I noticed this a while
ago but didn't think much of it (oops?) and it was brought to the
front of my mind when the larger Pleco was sucking on the shark thing
and I noticed bits of paint gone. The Plecos seem to be attracted to
these two decorations and will come back and ignore all the other
<They're foraging for algae, and to some degree consume
indigestible matter such as wood as part of the normal diet. I'd
throw in some bogwood and let them eat that instead. Certainly ensure
there's always something vegetarian for them to eat: carrot,
potato, sweet potato, cucumber. With luck, they'll ignore the
Should I remove them (the decorations)? Also, I have another decoration
in which air bubbles are forming under the paint. The paint doesn't
seem to be coming off though. Should I remove that one?
<You can if you want. If good quality ornaments, the paint and the
ceramic/plastic they're made from should be non-toxic.>
Fourth. About 2 days ago, I was watching my fish when their aquarium
lights were turned off and saw my red, 2 1/2" Oranda scratching
himself on the gravel. He did that twice and went back to sleep. A few
minutes later, one
of my Koi came along and did the exact same thing in the same area.
Then he swam a little ways and scratched himself on a nearby fake log.
Upon visual examination with the lights on, I found nothing strange and
(again) thought nothing of it. Yesterday, I was watching my fish again
and noticed the same Oranda go up to one of the filter output spray
bars and scratch himself against that repeatedly. The spray bar hangs
vertical in the water since I can't get it to hang any other way. I
looked over him again and found nothing. However, a few minutes later
he began swimming erratically and in short bursts when he suddenly swam
straight up and jumped out of the water.
This is where I did the water testing and the 50% water change. He
behaved normally throughout the duration of the water change but after
that when I was sinking a few flakes, he decided he wanted to bump up
fingers until I "petted" him. I decided to try something and
lowered my hand into the water and he swam halfway onto it and began
nipping until I "petted" him again. And this is the point
where I got concerned and decided
to add this onto my list of things to contact WWM about.
<I think this is a reaction to the non-zero nitrite level. Fix the
water quality. Nitrite and ammonia irritate the gills, and the reaction
of many fish is similar to that of parasitic infections -- they jump,
splash, and scratch seemingly wanting to scrape away the parasites.
They don't know there's no parasite, all they can feel is
something tickly on their gills.>
Later that night I gave them their second official feeding of the day
(which is a rather tiny amount) and he ate his fair share and begged
for more. He doesn't have anything wrong when I looked him over.
However, his tail has gotten kind of opaque and has a "fuzzy"
looking texture to it but there's nothing really on the tail. The
white and orange parts have just gotten foggy and his "stomach
fins" are normally red fading to a white and today those fins have
turned completely white except for the base and the fin rays(?) when
the red and orange typically were. His
dorsal fin is still perky.
<Again, I think this is the early stages of what can become Finrot.
Fix the water quality, and if you want, use a mild anti-Finrot
medication like Melafix or Stress Coat as a preventative against
Sorry about the really long message. Thanks for taking the time to read
all of it.
<Happy to help, Neale.>
Re: Just a few questions'¦ (Bob, thoughts on Koi indoors?) -
Hi and thanks for the reply, Neale.
On the sizes of the fish, the feeders are about 1"-1.5", the
larger ones are about 3", the Orandas are 2.5" and 1.5",
the Koi are a good 4"+, the Shubunkin is about 3.5", and the
fantail is 1.5".
On the Koi, are you saying that my best bet would be to get rid of
<As both Bob and I stated, Koi generally do poorly in aquaria. May
be fine for a year or two more. But the fact you have a non-zero
nitrite level won't be good for them even now.>
I don't know anybody who has a pond and I'm not sure if the
local pet store will take them back since it's been so long (and I
lost the receipt) and I don't want to ship them anywhere out of
town. For the nitrite level, I was gone for a few days and I think my
brother overfed them because the water was cloudy when I got back.
<May be so, but assuming you do a decent water change and check the
filter is working properly, any overfeeding should have worked itself
though by now. If you still have non-zero nitrite levels by the end of
this week, you have a problem.>
The Plecos seem to avoid each other unless there's food at stake
and the big Pleco usually scares off the little one.
I drop half a slice of zucchini in the tank. Everything vegetarian
seems to float into the unreachable parts of the tank and I end up
tying it to one of the decorations which the fish end up knocking
<Lettuce clips work great, and I use strips of lead weight -- sold
for tying down aquarium plants -- to hold down zucchini, carrots, sweet
potato and lettuce stems.>
What would be a good thing to use to weigh it down instead and how long
can/should I leave a vegetable in the tank before taking it out?
<No need to remove vegetables, though for cosmetic reasons you can
slurp up debris using a hose and bucket.>
Once again, thanks.
Butterfly Carp, in an aquarium, injured
Sorry to bother you again. Actually my butterfly carp's two scales
are bleeding and something is coming out of them. Is it a great threat
for my fish. I am sending the video clip because I was not able to
capture its image. Please tell me what can I do? ;-)
<Can't make out what "is coming out"... but otherwise
this looks like a physical injury (a trauma). Could this fish have
damaged itself on some decor (a sharp rock for instance)? Unless you
can identify the presence of a specific pathogen, parasite, I would not
add any curative, medicine here.
The fish appears otherwise active, healthy, and should heal on its own.
Koi w/Fin Rot 12/27/09
I have 3 Koi's in a 75 gallon tank.
<How large are these fish? This is a very small tank for 3 Koi. What
type of filtration?>
One of the Koi's developed what looks to be fin rot-white edge on
one side of fin that tears, turns white again and tears. It has loss to
where the other fin meets in a point. Also, the mouth developed a white
growth on each corner. The fish is still active and eats.
<This is a good sign.>
Someone maintains my aquariums and told me to use Melafix for a week,
which has not helped after several treatments.
<Finrot is generally caused by poor water quality, Alice. The reason
that the Melafix isn't working is that it's not a strong
medication -- some even say that it is virtually useless -- compounded
with what caused the problem in the first place -- poor water
Now I have been told to treat with Seachem Metronidazole.
<This medication is commonly used to treat protozoan infections, not
Finrot. So, it's not the right thing to use, anyway. I would
recommend Maracyn, but not until you've taken the steps to ensure
water quality is spot-on.>
Haven't started because I was told the risk to my fish is high
<You're right. Medications can disturb the biological cycle, and
over- or mis-medicating can stress and kill fish.>
In a real panic and don't know what to do to cure my fish and not
hurt the others. Can't set up a hospital tank.
<This shouldn't be necessary, as fixing water quality will
likely fix the sick fish. However, if this becomes necessary, a
"hospital" tank can be a big Rubbermaid tub with a sponge
filter -- no need to go all out, really.>
Noticed you ask some about the various levels, but since I have someone
else maintaining the aquariums I would not have that information.
<I would obtain it for a few reasons. For one, these are your fish,
and you care about them more than anyone else ever will. Therefore,
you've got to be the one making sure that they're being treated
well. Another is that this once-monthly cleaning probably isn't
enough, and the numbers gained from Ammonia, Nitrite, and Nitrate tests
would indicate if this is so. Yet another reason is that I assume that
you're paying this person to care for the tank; if they are really
doing what they should be doing, providing this data should be no
problem. The fourth reason is that the fish is now sick, and you're
the one having to fix him, not the caretaker. So, you need to take the
informed approach and understand what's going on. The fifth is that
these aren't fish for a 75-gallon tank, and there's going to be
a point at which their environment will need serious upgrading. Those
numbers, once you understand what they are and what they mean and how
they relate to one another, will help you decide when it's
Tank is cleaned every 4 weeks.
<This is likely not enough for 3 Koi. Bi-weekly water changes are
really a must with these large, messy fish.>
Please help me save my fish.
<You'll need to get those numbers in order for any decision to
really be made. If they're off, water quality will have to be fixed
before any fish gets better, and fixing them may result in the fish
healing on its own. If they're not, then that's the green flag
to go ahead and medicate. If this is the case, a hospital tank would be
the best step. Obviously, this would be a silly thing to do if the
problem is water quality -- thus, the reason for figuring that part out
first. Please take a look at the following links, and feel free to
write back if you need any more help:
http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm (and the
linked files below the title)
Re: Koi w/Fin Rot 12/29/09
Thank you for your information. I have also looked at the websites
My husband died 3 years ago
<I'm sorry to hear.>
and we had 3 large ponds with over a hundred fish.
When I moved I found them good homes, but wanted to keep a few of
his Koi. They
are not that large yet.
Also, have 2 other aquariums with goldfish that are doing fine.
The girl who maintains my aquariums works at a local fish store and I
took a sample of water today and was only told, the water is fine.
<Yes, but what is "fine?" The reason this is SO important
is that these problems are coming from somewhere! We have to figure out
why they showed up in order to make sure the fish heal.>
My fish is still active, but the fin rot and the white growth at
corners of mouth has had no change.
<I am glad the fish is still active.>
What do you think the problem with its mouth is? Failed to
mention Maracyn was the first treatment used.
When this didn't work, Melafix was suggested. Neither has
<Okay. When you used the Maracyn, did you complete the treatment?
This should have taken care of both problems. The Maracyn should have
done something -- in my experience, this is a medication which usually
yields results. This is why I'm worried, and I really, really want
you to take charge of this water testing thing. You might have to
actually say, "It's nice that it's fine. What are the
numbers?" Or, just buy the tests so you can have them for your own
usage, interpretation. The test kits are really simple to use, so
don't be worried about that.>
My filter has 2 bio-wheels.
<Okay. So, your filtration may not be up to par for these fish. This
sounds like a large hang-on-back filter, but you're really looking
for filtration that turns the tank's volume over 8 to 10 times, and
especially with Koi. Another reason those numbers would really help.
What you can do to attain this type of turnover is, say, add a large
canister filter in addition to your hang-on-back.>
Took the carbon filter out to treat (24 hours ago) and used the Seachem
once, feel that I should put it back, to not risk poor water conditions
and will not use the Seachem again.
<Okay. That's fine -- I don't think this is among what you
need to be treating with anyway.>
Today I was told that she doesn't want to be responsible for
killing my fish and is afraid if we keep trying, its
<Well, that's a crazy answer. What does she think will happen if
you don't treat the fish? Either way, why won't she provide you
with the numbers you need?>
How do I restore the fin or keep the fin from getting worst and I have
no idea about the mouth. Will definitely schedule bi-weekly on this
<I'm glad to hear that. I really think you should buy some test
kits and test that water yourself, Alice.>
It will hurt so much to lose his fish.
<This is why you should go ahead and buy those test kits, I think.
As I said in my earlier e-mail (without knowing any of the context
here), you care for these fish more than anyone else ever will -- why
leave the big decisions to anyone else?> With the various
medications, is it possible it will heal in time?
<Yes, this can heal. But, we've got to start at the beginning --
let's get those numbers. Let's figure out why this started in
the first place. If those numbers reveal water quality to be spot-on,
then you know you can treat, and see results. But, if you ran the
entire course of the Maracyn and saw no change, I worry that
there's something going on with water quality. The Maracyn should
have worked on both of these. I'd like to include this:
http://www.wetwebmedia.com/fwsubwebindex/fwfishmeds.htm because I
that, after we ensure the water is what it should be, another round of
treatment is in order. I hesitate to recommend Maracyn again without
knowing why it didn't work before. So, you should be able to take
this list and determine what is available to you at your LFS. There are
some other Mardel products, such as the MarOxy, that you could try.
Please, though, don't treat without first trying to determine why
this occurred -- it's really important that we figure that out, or
the fish won't heal properly, and worse, your fish will be open to
having this happen again in the future.
Butterfly Koi; indoors
Hello I have a 180 gallon aquarium (8ft long) and would like to know if
i could keep butterfly koi?
<Depends what you mean by "keep". Will they live in such a
tank? In theory, yes, given adequate space and very generous filtration
(we're talking at least 8 times the volume of the tank in turnover
per hour) Koi Carp can be kept indoors. However, very few people are
able to provide the conditions they need as indoor fish. I'm a bit
confused by your aquarium being 8 feet long and yet only containing 180
gallons. Let's say this tank is 8 x 3 x 3 feet, that's 72 cubic
feet in total, or 538 gallons. So something's amiss here. A tank 8
by 2 x 2 feet would only be 32 cubic feet, or a mere 240 gallons, but
you can't keep adult Koi in tanks two feet wide since they get to
more than two feet in length! So you might want to go back, measure
your aquarium, and then ask your question again. A 538 gallon tank
would be acceptable for Koi, being essentially an indoor pond, though
you would need massive filtration. Whenever I've seen Koi kept
indoors successfully, by
which I mean they reach full size and live a normal life, they're
in an indoor pond coupled to a pond-grade filter system. Now, I'll
also make the point that on the whole Koi aficionados tend to look down
(being polite here!) on Butterfly Koi. They are not acceptable at Koi
shows for example, and they cannot be graded (which, among other
things, means the quality of Butterfly Koi varies wildly, and as with
anything in life, you often get what you pay for. Butterfly Koi are
essentially absent from the trade in Europe and Japan, and are really
only popular in the US, where tastes are somewhat different ("less
snobby" or "less discerning" depending on your point of
view). What I'm saying then is that Butterfly Koi, like all
are extremely demanding when kept indoors -- they're pretty
demanding kept outdoors, too! -- and without any sort of quality
control, it's all too easy to end up with fish with congenital
defects, poor disease resistance, and so on (think of puppy mills in
terms of dog breeding, and apply that to breeders cranking out
Butterfly Koi). Do your research, budget carefully for the needs of the
fish, and take some time to locate a reputable breeder of Butterfly Koi
who can supply you with good quality fish. Cheers, Neale.>
(RMF, what do you think of these long-finned fish?) <<As time has
gone by, I've "gotten used to" this variety, and it is
indeed included in some Koi shows here in the U.S. nowadays. However,
not "my cup of tea". BobF>>
Goldfish has dark red spots and looks like missing
scale (RMF, any wisdom to share here?) 4/15/2009
I work in Afghanistan on a military base.
<Ah, not a part of the world we get many messages
I purchased a small (5.5 gal) desktop tank on the internet.
<OK; but do be careful, these small aquaria really aren't
do see here:
My local national employees brought a goldfish for me from a
'pet store' in Mazar-E-Sharif. I have had many fish in
the past and I would say it is not a true 'comet type'
goldfish. It is probably some type of river fish.
<Perhaps a wild carp of some sort? Or a minnow? A photo would
be both fun and useful!>
I do weekly water changes with bottled water.
<As in drinking water? That should be okay; but don't use
deionised or distilled water, as that will quickly sicken your
fish.><<Actually... the system size, this water... are
likely the sources of trouble here. RMF>>
Recently my fish developed dark red spots (like boils) on the
sides and it appears some scales may be missing.
<Does sound like Finrot or some other type of opportunistic
bacterial infection.><<Environmental in origin.
I have no access to any products (other than the internet) so I
am looking for a home remedy.
<Unfortunately there really aren't many reliable remedies
for bacterial infections beyond the use of drugs. The addition of
salt, for example, can help under some circumstances (3-10 gramme
per litre) but it's not
reliable. It's drugs like Nifurpirinol (0.1-1 milligrams per
litre) and Oxytetracycline (20-100 mg/l) that are used most
successfully. Failing that, certain organic dyes and other
chemicals can work: Malachite Green
(0.1-0.5 mg/l), for example. A vet or MD may be able to obtain
these for you. Do note though that since these infections are
opportunistic, caused by otherwise "good" (or at least
harmless) bacteria, if you don't fix the root cause, usually
environmental conditions, the fish won't get better.>
The fish has become more lethargic but seems to be breathing
Every couple of days I put a small amount of table salt in the
water. Do you have any suggestions?
<Done my best.>
<Hope this helps, Neale.>
|Re: Goldfish has dark red spots and
looks like missing scale (RMF, any wisdom to share
I appreciate your quick response. I know the small tank can cause
problems. I could not find any dealers online that would ship a
larger tank to an APO address.
<Ah, I see. Unfortunately, science isn't all that flexible!
If a fish needs 30 gallons, it needs 30 gallons. I'm mindful of
the issues when governments set fishing quotas as an example. The
scientists say the population is only so big, and the fishermen can
tank X fish per year if the population is not to go into decline.
The fishermen say they need twice that number otherwise they'll
lose money and jobs. The politicians, trying to split the
difference and give everyone a compromise, choose some number
between X and 2X. Sounds good on paper, but science doesn't
compromise, and the fishery eventually collapses. In the case of an
aquarium, you need a certain amount of water volume to dilute the
ammonia and other wastes produced by a fish (or fishes) of a
certain total mass. With small fish like guppies, this is where the
"inch per gallon" rule comes from: you allow a gallon of
water for each inch of fish kept. Likewise, you need a certain
sized filter to break down those wastes quickly enough that the
dilution effect of the water volume remains within safe levels. To
cut a long story short, Goldfish need about 20 gallons when small,
but 30 gallons once they're above a couple of inches in
I do use bottled drinking water (see picture) for the water
changes. The bottle lists the composition / mg in each .5 liter
bottle: Calcium-16, Magnesium-16, Sodium-10, Potassium-<1,
Sulfate-3.5, Chloride-80, Nitrate-<1, Fluoride-<.01, Total
<Should be fine. The pH is important though, Goldfish preferring
a pH around 7.5-8.0.>
I have attached a couple pictures of my fish and copied my wife on
this response. She would be able to go to a store in Wisconsin and
send me the products you previously suggested.
<That would be helpful.>
The mail takes about 1 week to arrive.
<Hmm... try adding some salt to the water as mentioned last
time, but I fear this will be a rough week for all concerned. This
fish (seemingly a Carp, Cyprinus carpio, rather than a Goldfish,
Carassius auratus) has a bacterial infection of the type usually
called "Ulcer Disease" or else Finrot of some type.
It's essentially an opportunistic infection caused by otherwise
harmless bacteria invading the body of a stressed fish with a
weakened immune system. I really can't stress this strongly
enough: the tank isn't big enough, and the conditions in the
water are likely dire. No amount of treatment will help. Since this
is a pond fish (Carp = Koi) perhaps building a pond is an option? A
large plastic drum of some sort perhaps? Otherwise, to be
completely honest, I'd painlessly destroy this fish and stock
with something appropriate to a 5-gallon system. Perhaps some local
Killifish? Of course, wandering off into Afghanistan looking for
unusual aquarium fish might not be all that safe! But would make
one heck of a National Geographic special!
Thanks again for your help and give an extra hug to everyone in
your family for all those of us who are separated from ours.
Bagram Air Field, Afghanistan
<And good luck to you and all you do out there. Cheers,
Koi in a reef tank 11/25/08
I live up in MN and have my 3 Koi in a tank in the house for the
winter. It is a bare bottom with nothing in it. I have a lot of fake
and dead coral pieces. I was thinking it might make an interesting tank
to put the coral pieces in the Koi tank. Will this negatively effect my
water parameters and cause an unsuitable environment for my Koi? I do
not want to harm my Koi but want to make their winter home a little
<Hello Walt. Fake coral obviously has zero effect on water
chemistry, and should be just fine in any freshwater tank. As for dead
coral (something I'm sure Bob Fenner will agree is not something we
encourage people to buy, because of the way it is collected) then if
you happen to have a few bits, by all means add to a tank containing
hardwater-tolerant freshwater fish. Koi prefer hard water to soft, so
this isn't going to be a problem from that angle, provided the pH
doesn't go much above 8.0 and the hardness isn't much above 25
degrees dH. However, coral is "scratchy" and big, clumsy fish
(like Koi!) may find themselves damaged if kept in a relatively small
habitat like an aquarium. It all depends on the size of the tank
compared with the size of the pieces of coral. If it's a 200 gallon
tank and the lumps of coral are the size of your fist, then adult Koi
are unlikely to come to any grief. But in a 55 gallon tank, with corals
size of your head, then things could be different. Cheers,
Re: Koi in a reef tank 11/25/08
Neale- thanks for the response. I agree dead coral is something to
avoid but it was given to me many years ago and I never used it in my
<Cool. The reason I mention things like this is not necessarily for
you, but for other readers browsing our site. In the UK (and indeed the
EU generally, I believe) dead coral cannot be traded at all, and
I'd like to encourage people around the world to generally avoid
buying the stuff. Live corals are one thing -- they have to be
collected carefully -- but dead corals are relatively cheap, and
there's little incentive to collect them sustainably.>
They are small Koi 2 3" and 1 6". I was only going to use the
smoother corals as I am not sure which are fake and which were
<Ah, I see. You should be fine. Koi are such special fish that it is
ALWAYS worth taking extra care when housing them, especially indoors.
The benchmark with Koi is high (in my opinion) because it's decades
before they really develop their full potential. They can also be
incredibly expensive, even the "bargain" Koi being relatively
I am going to add a couple pieces and see how it looks.
<Good luck, Neale.>
Transferring fish... Koi, goldfish... in a 55? 6/25/08
Hi! I recently purchased a 55 gallon aquarium (last Sunday) The Goal is
to put 2 Koi and 2 black moors which are housed in a 20 gallon tank
into the new 55 gallon tank. I have put 2 gallons of water from an
established 10 gallon tank. <Water contains almost no filter
bacteria, so adding water from one tank to another doesn't do
ANYTHING to speed up maturation.> 5 gallons from the 20 gallon tank
added cycle brand live bacteria as recommended. I also took the old
filter from 20 gallon tank and cut off pieces of it and threw them into
the 55 gallon. <The good news is that "old" filter media
will instantly mature a new aquarium (if used in sufficient quantity).
By contrast, potions like 'Cycle' tend to be a bit hit-and-miss
in efficacy.> The 55 gallon has been running since Sunday. <If
you have matured the aquarium with filter media, remember: those
bacteria can starve. ALWAYS add sufficient ammonia or fish food to keep
them happy. A couple of pinches of flake work great. As the flake
decays, it produces ammonia, and that feeds the bacteria.> My
question is this... How long should I wait before adding the fish?
<Don't. Add fish right now. The old filter media will have
matured the new filter, assuming the water chemistry is similar between
the systems. You can take 50% of the media from a mature filter and put
into a new filter. The old filter will carry on working fine, and it
will mature any new media put into it. The new filter with the old
media (confusing, I know) is effectively a mature filter now! This is
called "cloning" a filter, because what you're doing is
splitting one mature filter into two mature filters. It is BY FAR the
safest and quickest way to mature an aquarium.> The pet store told
me to get a few tiger barbs to help with cycling but I don't want
any more fish!! lol <Rubbish advice.> I am extremely attached to
these 4 fish and don't want to harm them in any way. I am afraid to
move them to their new home too soon. Any advice you could give me
would be very appreciated. <Do an ammonia test. Even with flake
adding to the water, you shouldn't detect any ammonia 24 hours
later. This is because the bacteria hitch-hiked from the old aquarium
into the new aquarium on the filter media you moved into the new
filter.> Oh, also the tank came with a whisper 60 filter (hangs on
the tank) I was thinking to be on the safe side to add another whisper
20 on the other side? Thanks Oh by the way, I didn't add any used
gravel because I went with a different color in the 55 <Do remember
fish can't stand brightly coloured gravel. If you want happy fish,
especially goldfish, choose fine gravel or even better smooth silica
(silver) sand. Don't use too much or they'll make a mess, and
you won't be using live plants so a big depth of substrate
isn't important. Cheers, Neale.>
Re: transferring fish -- 06/26/08 Thanks for the information.
(I feel really stupid now...lol) When I did the filter I was unaware
that I was supposed to take the inside (charcoal) out of the old
filter. <You don't have to. Old charcoal is simply biological
media by another name; it no longer removes dissolved organics. Carbon
only removes organics (the yellow stuff in the water) for about 2-4
weeks from brand new. Unless you're replacing it every 2-4 weeks,
it isn't doing anything other than supporting biological
filtration. Hence my usual advice to freshwater aquarists to skip the
stuff entirely in favour of high performance biological media such as
quality ceramic noodles or sponges.> I just cut off the dirty cloth
stuff and threw it into the new filter (duh! My Bad!) <The sponge in
the old filter is precisely what you want; the think cotton cloth stuff
is likely the pre-filter, and of no particular value or harm. It is
meant to replaced every month or two, the idea being it catches solid
waste (e.g., dead plant fragments) leaving the biological/chemical
media free to react with the water.> Problem is that now the old
filter was thrown away and new one put in the 20 gallon tank on Sunday.
What should I do now? <Not sure what you're asking. If
you've put sponge, ceramic noodles, or even "old" carbon
from the old filter in the new filter, then the new filter will almost
certainly be biologically active. If you have done none of the above,
and only used aquarium water or a bit of gravel from the old tank to
"seed" the new filter with bacteria, you actually haven't
done any such thing, and the tank will need (at least some) cycling. In
any event, you ammonia or nitrite test kit will help here: if you
detect either, then you have a filter than needs cycling. If you have
zero ammonia/nitrite, then everything is fine. Test kits beat theory!
Bent tail, Koi in tank, using WWM
4/16/08 I have 2 Koi in a 55 gal. D.A.S. tank. <Will outgrow
this in time> Water is fine. One of my Koi started to get a little
kink in his tail, but everything was fine (swimming, eating) It has
gotten worse. His tail is bent up (almost in a "V" shape) and
now is not eating and is laying on the bottom. Has been this way for a
couple of days now. He is struggling to survive, so I am trying to help
him. Thank you Charity <Mmm, well, such bent tails can be a
manifestation/expression of genetic anomaly, nutritionally derived,
environmental (too small quarters), or pathogenic in origin... See
here: http://wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm put
the term "bent tail" in the search tool, read the cached
versions Bob Fenner>
Sick goldfish... and Koi, env. 2/29/08
Dear Bob I had a 15cm Koi and comet in a 1 metre tank. Koi suddenly
died for no apparent reason overnight and the comet who was silver
started turning pink and the edges of his back and tail seem to have
what looks like bleeding veins as though he is bleeding internally.
I've had him for 7 years without any problems. Can you please
help?? Sincerest and heartfelt thanks Pearl in Australia <Hello
Pearl. The problem with the comet is almost certainly Finrot. The
symptoms here start with congestion in the veins of the fins as the
bacteria set in (that's the pink stuff you see) followed by the
tissue dying (goes white) and then eroding (so the fins look ragged).
Finrot itself is almost always caused by water quality problems.
Perform (at the very least) a nitrite test. Check the filter is working
properly, and regardless do two 50% water changes today (a couple hours
apart) to flush out some of the pollutants. Stop feeding the fish.
Being treating with a reliable anti-Finrot medication (remember to
remove carbon if present in the filter). Melafix/Pimafix aren't my
recommendation for this, although often sold as such. Use a decent
copper-based medication or antibiotic. Koi really aren't indoor
fish, and certainly can't be kept in a 1 meter tank -- I'm
guessing that's about 180-200 litres/40-50 gallons, which is
adequate for Goldfish but not Koi. Koi are simply too sensitive to poor
water conditions. Cheers, Neale.>
My Oranda fish lost it's eyes -02/20/08
Hi guys, I searched the site but couldn't find my answer. My Oranda
fish is the only Oranda in a 55 gallon tank along with 3 goldfish and a
Koi. Three weeks ago I noticed one of my Orandas eyes missing and now
today another one. I have seen all the fish at one point or another
pick at his fins but, HIS EYES? Why do they do this and can he survive
like this? Will the others continue to pick at him? So concerned!
Thanks Concerned new fish mommy! Have a wonderful day! Jessica
<Hello Jessica. Eyes are -- after fins -- the bits on a fish easily
damaged by fighting. So the best thing a "concerned fish mom"
would do at the first signs of aggression between fish is to separate
them so this couldn't happen. It is unusual for goldfish and/or Koi
to be aggressive towards one another, but they can be boisterous, and
it is ALWAYS recommended that fancy (double-tail) goldfish are kept in
different tanks to single-tail goldfish and Koi. In other words:
Orandas, moors, Ryukin, etc. should all be kept in different to tanks
to plain goldfish, comets, and Shubunkin's. I'm guessing that
you didn't do this. If you didn't, you know now! As for
therapy: treat with an anti-Finrot/anti-fungus medication first, to
prevent a secondary infection. Do also check the water quality,
specifically nitrite, to see that there isn't a problem there. It
is entirely possible that minor damage (that could have healed) quickly
turned bad because of poor water quality. There should be zero ammonia
and nitrite in the system. In addition, check water chemistry for the
same reasons. Goldfish need hard (10+ degrees dH) and basic (pH 7.5)
water conditions. Will the eyes grow back? Obviously not. Can he live
without them? Yes, provided he is kept alone. He will navigate using
his lateral line and forage for food by touch and olfaction, but the
goldfish with eyes will be able to out-compete him at feeding time. The
result will be a lot like dinner time at the home of Phineas. Cheers,
Some Koi Flashing but not All 2/1/08 Hello, <Hi
there> I have a 125 gallon tank with 9 fish in it, 5 Koi, 3
Comet and 1 Fancy Comet. <I see them in your pic... a bit
crowded physiologically> Sometimes especially in the evening
once the lights go off on the tank, a couple of the Koi will
flash, turning to their sides and making a swift rub on the
bottom. I will also notice sometimes that they flick their fins
rapidly as if something is bothering them, but upon visual
inspection I see nothing. <Mmm, there may be naught> I have
treated them for parasites with Jungle Labs Parasite tabs, added
some salt to the tank, and I do regular water changes daily,
about 20 gallons, during which I grab most of the waste off the
bottom of the tank. The tank has 2 Eheim Profession II 2080
canister filters on the tank. Further, the fish that do flash do
not appear to have any open wounds or irritated spots. When I
have done water quality checks, the ammonia, nitrate and nitrite
levels all appear zero... only the ph seems a little high at
around 7.8. The tank water fluctuates from 67-69F depending on
the time of day. <Brrrrrr! You keep your home cool> So what
I cannot figure is, what is the problem? Or am I just paranoid?
<Mmm, perhaps cautious... but unless you have introduced
(through plants, new fish, live food) some new parasite/pathogen,
there is likely nothing disease wise wrong here> I attached a
picture of the setup. Regards, Benjamin Schmaus <I would cut
back on these fishes feeding... they're apparently
"fat"... Cheers, Bob Fenner>
Re: Some Koi Flashing but not All
2/8/08 Hello Bob, <Ben> So the swollen eyes went back
to normal on that one koi and he is also eating again. However he
still flashes now and again I read the following: General
Hardness influences Calcium levels in the blood, and the osmotic
regulatory systems of fish are affected by concentrations of
dissolved salts. High levels could irritate gill membranes, they
may look slightly swollen, and the fish may be seen flicking or
rubbing in the water. <This is so> My GH is around 180ppm
which is rather high. Could this be contributing to my fishes
behavior? Maybe one is a little more sensitive? <Is
possible... though all koi, most all fishes... do flash to a
degree... I do think you and this Nishikigoi are "out of the
woods" at this point. I hope this metaphor means that it
will be okay. Cheers, BobF> Benjamin Schmaus
Re: Some Koi Flashing but not All 2/3/08 Hello
Bob, <Good day Ben> Thanks for the response. So other then
a cold basement and fat fish, there should be no worries on the
flashing. Like I said, it happens fairly rarely. <I
wouldn't be concerned> You are correct that it is a bit
crowded. That will change once spring arrives and I can place
them back outside in their summer home. I attached a picture of
that location as well. Regards, Benjamin Schmaus <Ah, good.
Re: Some Koi Flashing but not All 2/4/08 Hello
Bob, <Ben> Here is an update on one of those fishes that
was flashing... Today I noticed that the eyes were bulging more
then normal and when I fed them, the koi would take in food but
then spit it back out. There appears to be no sign of him being
bloated or pine-coning. He also exhibits what one might call a
cough. <Mmm, something apparently amiss> Water quality
appears normal. Although PH might be slightly low, 7.0 side and
water hardness is up there. No ammonia, nitrites or nitrates. The
only thing that changed from yesterday to today, was I replaced
the fine filter pad in one of my Eheim's and also changed the
charcoal. Both were rinsed in water before placing. <Mmm, but
only the one fish affected... and only one pad, and no detected
nitrogenous anomaly...> The other fish seem fine and all are
eating. Regards, Benjamin Schmaus <If you had another
system/tank up and going, I might move the one not acting quite
right... Perhaps it (literally) swallowed a bug... BobF>
Lethargic koi, env. dis. - 11/26/07 Hi
Robert, <Carson> I have a small tancho koi that is about
4-5" that I am currently keeping in a community aquarium due
because we haven't built a pond yet. It was purchased at the same
time as a Kohaku koi that is currently 6-7". They were the same
size when purchased. The past couple of days the tancho koi has been
very lethargic and only really moves when you approach the tank.
<Mmm, how long ago was this Nishikigoi purchased? What water
conditions was it under at that time?> It doesn't seem to want
to eat very much. The ammonia level is at .25 ppm, <Toxic!> the
nitrite is the same, <Ditto. These MUST be zero> the pH is at
6.6, the nitrate is at 0. <You are fortunate here... if these values
were higher the NH3... would be NH4OH much more... and deadly> The
water temperature is at about 74 degrees f. There doesn't seem to
be any spot of ich and none of the other fish are exhibiting any
unusual behavior. The tank is 55 gallon with two filters (one sixty
gallon one thirty gallon) that are constantly going, The tank consists
of the following fish 1 - 4" tancho koi 1 - 6" Kohaku koi 1 -
5" comet goldfish 2 - 2" comet goldfish 3 - 2.5" bala
sharks 1 - 3.5" golden shark 1 - 4" tinfoil barb 1 small
freshwater crab. Their diet consists of flakes, freeze dried brine
shrimp, freeze dried krill, and occasionally bottom feeder shrimp
pellets. <I would cease feeding period till the ammonia and nitrite
are zip, nada, gone> Is there anything that I can do to help my
tancho koi? Carson L Maestas <... you should read... On WWM re water
quality, environmental disease... Your livestock is in grave danger.
Carpet surfing Koi 11/28/2007 Hello guys,
Last Saturday morning I found my Koi carpet surfing. I live in MN so he
was inside in an aquarium with a full hood for the winter. He knocked
the plastic lid off the hood. It was still dark so I found him by
touching him with my foot.. Not a great feeling. Anyhow he was still
alive so I drained some tank water into a bucket and placed a power
head in the bucket and was able to revive him. He is back in the tank
with the 2 other Koi and 2 goldfish. He is in very rough shape and lost
a lot of scales and body slime. He is about 12" and was a
beautiful bright white with orange saddle. He now looks orangey white
especially on his head and the one side, I would assume that is the
side he was laying on. Anyhow he is breathing the same as the others
but not very active and has yet to eat since the incident. I have been
adding stress coat to the tank in an effort to help. Also, the tank is
not heated so the temp is around 66. Any suggestions to get him to eat?
I am feeding them Koi food from Blackwater Koi Farm ( I am pretty sure
that is the name). Should I heat the tank? Will that help him recover?
Any other products to add? I added barley pellets in the pond would
they help in an aquarium? I am running a filter with carbon right now.
I also have saltwater tanks so would adding a little salt be beneficial
to the Koi in the tank? Any suggestions to get him eat first and then
all the way back to health would be appreciated. Thanks so much, Walt
<Hello Walt. Your Koi will get round to eating precisely when he
feels like it, and not a moment before. There's no real advantage
to trying to speed this up. Koi can go weeks without food. So leave him
be, and simply offer a variety of the usual foods you give them. Plant
material like pondweed could be placed in the tank so he can have a bit
of a graze if he gets peckish. Heating the tank won't really
provide any advantage unless the tank gets very cold; 66 F should be
perfectly tolerable for a Koi. Adding Stresscoat and salt may have a
marginally positive effect, but for now I'd dose the tank with an
anti-Finrot/Fungus medication just to make sure no secondary infections
set in. This is the most likely problem, because the mucous and skin
dried up, and they're the first line of defense for a fish.
Naturally, remove carbon while treating the fish, and in my opinion,
never replace it. Instead add more biological filter media and ensure
you're doing substantial weekly water changes. Together these will
greatly enhance the water quality, limiting the chances of secondary
infections. Once that's done, the fish should make a speedy
recovery. Good luck, Neale.>
Re: Carpet surfing Koi 11/28/07 Neale- Thanks for
the quick response. I will pick up a few plants for him. Also what
other fresh foods would you recommend? <Carp are, at heart,
omnivores. Anything soft will appeal. Tinned peas, mashed prawns,
bloodworms and so on will all be good. I find omnivorous fish often
enjoy algae ripped out of a pond. They peck away at it for hours.> I
think Zoecon is for Marine fish but would adding Garlic Xtreme or
Zoecon to the food help? <Worth a shot. But Koi generally have very
good appetites when they're healthy, and I suspect you'll find
he'll take food once he's settled down.> I will switch to a
medicated anti Finrot/fungus treatment and remove the activated carbon.
I have been doing saltwater so long I am blanking out on a good
biological for a freshwater aquarium. Do you have a good suggestion or
a link to do some research? My pond pump equipment is too big for the
aquarium. Would barley pellets help in an aquarium. They seem to really
help in the pond. <This is for fixing algae, right? Not sure
they've ever been used in aquaria. Generally, algae isn't a big
deal in aquaria. Yes, you get algae on the glass, but scraping that off
is so easy why bother with anything more complex? Green water -- that
scourge of small ponds -- just doesn't happen in healthy aquaria.
So I wouldn't bother with them.> Thanks again, Walt <Happy to
help. Cheers, Neale.>
Re: Carpet surfing Koi 12/5/07 Neale
Thanks for your efforts but He passed away last Friday. My wife called
when she got home to say he was twitching on the bottom. When I got
home he was not moving or breathing. I tried reviving but with no
success. The sad part is he seemed to be getting a little better
everyday. He must have been out of the water long enough to do
permanent damage. Thanks again, Walt <Walt, too bad. Sorry things
didn't work out this time. Good luck with the rest of your fish!
Curios.... ities... Stocking, not-stocking Koi in fish
tanks... some goldfish 11/16/07 I was planning to buy a
new aquarium and want to buy some Koi, or any Chinese type goldfish
such as the lionhead. How many can fit into a 55 gallon tank? Fully
grown I mean. Thanks for the help. <The short answer is 0 Koi carp
and maybe 4-5 goldfish, depending on their type. Fancy goldfish tend to
be less active than normal, non-fantail goldfish (i.e., plain goldfish,
Shubunkins and Comets). Koi carp simply cannot and should not be kept
indoors. They never do very well, and their large adult size (around 60
cm) makes them incredibly demanding in terms of water changes and
filtration. If kept indoors at all, they need tanks measured in the
100s of gallons. Do also remember that fancy and regular goldfish
cannot automatically be mixed. The really disfigured goldfish such as
Celestials and Bubble-eyes have a hard enough time finding food and
avoiding infections. So keep these sorts of fish on their own. Robust
fancy goldfish though, particularly Black Moors, tend to be reliable
tankmates for regular goldfish. Cheers, Neale.>
Please help =] Koi/aquarium maint.
11/15/07 Hello. I need some help and the web sometimes confuses me
and doesn't really help me find my answers. <... You're not
alone here. The "Net" is not designed to inform... but more
to "chat", sell stuff... One must search for more informative
sites...> So I was hoping you guys could. I'm helping my grandpa
find a new filter or figure out what's wrong with his tank. He has
approximately a 40 gallon tank and he has to clean it about every two
days. He has Koi in there <Stop! This is "a/the" reason
right here... the type of fish (ornamental carp) and a small volume...
They're messy... really need to be in a pond> so he has to bring
in gallon buckets of pond water when he cleans it. <Oh! You have a
pond. This bringing water in is a very good practice> He says it
needs some of the bacteria from the pond in there. He has 4 Koi in the
pond. Right now he's using a Whisper 20-40 filter. <A good
product> Is there a different filter he should use or is there
something else he should do? <Mmm, are the Koi in the tank and not
in the pond for a reason? I would add another outside power filter
here... and perhaps a mechanical aerator (bubbler), but you will still
need to change out a good deal of the water weekly. Perhaps a pump
would help here.> I don't think he should be having to work that
hard. Thank you greatly. sorry if this is confusing. <A small
submersible pump... one that can be hooked up to a garden hose... and a
shut off valve, ball type like for irrigation... at the end... will
help in moving the water... The outgoing water can/should be
gravel-vacuumed, placed on