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FAQs about the Imperator Angel Systems

Related Articles: Imperator Angels, Pomacanthus Angels, Marine Angelfishes

Related FAQs: Emperor Angels 1Emperor Angels 2, Emperor Angels 3, Emperor Angel ID, Emperor Behavior, Emperor Compatibility, Emperor Angel Selection, Emperor Feeding, Emperor Disease, Marine Angelfishes In General, Selection, Behavior, Compatibility, Health, Feeding, Disease,  

Angelfishes for  Marine Aquariums
Diversity, Selection & Care
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by Robert (Bob) Fenner

Our Imperator Angel and more... System f'       2/16/17
Hi Bob/ crew , We have an imperator angel and a yellow tang in our 5 ft tank that is in our garage and they are the only occupants of the 5ft tank (apart from live rock)! The yellow tang is about 7-8 years old and the imperator is about 6-7 years old,(we had him since he was half the size of the yellow and watched him change from juvenile to adult colours ), now he is about 8 1/2-9 1/2 inches maybe a bit more ,We also have indoors, a reef tank that is only 40” long and this tank has in it (live rock) and a brown tang, a coral beauty , two Snowflake Ocellaris clowns , two chalk Basslets and two Chromis. The corals are bubble coral , torch coral , several Acans and small polyp stonies and an open brain. We also have in a quarantine tank two larger white stripe clowns (thought could maybe go in with the yellow and imperator (can grow to 6” but not sure now), a fairy wrasse destined for the reef and two shrimps ditto! Our question is this: we know the imperator would be better off in a bigger tank but as we are now pensioners we can only perhaps handle one bigger tank I,,e, 6ft to 6ft 6” wide at most! But could perhaps go taller or wider (back to front), the question is can we put all our inhabitants into this larger tank as we cannot risk any of them (mainly the imperator and the yellow) in anyone else's care after all these years!! (they really are like pets) I expect we could keep the shrimps in a small tank if they would not be safe with the imperator! Your advice/opinions would be most welcome as its down to your site that has allowed us to be successful (so far) in keeping these beautiful fish and corals ! regards Jennifer
<A good question... difficult as Imperators are individualistic. I would not trust the large angel with the corals you list; too likely to be nipped or outright consumed. I might suggest selling/trading in this angel, and moving the five foot tank inside the house... and putting the rest together. Bob Fenner>
Re: Our Imperator Angel and more...     2/17/17

Hi again Bob , Thanks for your very speedy reply! I guessed you might say that I suppose, clutching at straws... I think we will have to leave everything as is for now while we think! We have had the Imperator Angel since it was tiny about 3 inches and have had him for 6-7 years i.e. he is a bit older than that but we don’t know how much older. So you see it would be a big wrench to get rid of him now!
<Ah yes; these intelligent animals do become companion pets>
We will have to wait a bit longer and see... But once again thanks for your dedicated help to all who need it , it’s very much appreciated! Regards Jennifer
<Thank you Jen. BobF>

Re: 12 Inch Emperor Angel won't Eat       5/3/15
Hi Bob,
<Hey Chad>
Here is an update with pictures. Emperor was eating PE Mysis, Hikari Jumbo Mysis, NLS Thera A 3mm pellets, Hikari Marine A, OSI Spirulina pellets, clam and Nori so I think I made the switch to prepared foods but the persistent parasites just won't seem to go away.
<See WWM re the combo. treatment of Prazi and Metronidazole... in foods if poss.>
I have stayed away from treatment as the fish continued to eat but now today the fish seems interested in food but only nibbled at a clam and wouldn't touch anything else. Breathing is around 100-110 per min which is better than yesterday.
Based on the pics do you think I should still stay the course with no treatment?
<Mmm; no. As alluded to above>
I hate to move a big 13 inch fish and stress him out more.
Water parameters are still at 0 Ammonia, 0 nitrite, 20 nitrate, PH 7.9, KH 10, Temp raised from 77 to 79.5. I have been doing 50 gal water changes per week in 500 gal system to keep nitrate low with heavy feeding. Can you confirm if this is ick by the pictures?
<Nope. But doubtful it is this Protozoan... much more likely Flukes>
<.... an order of magnitude file size in pix. Am surprised your mail didn't bounce. B>

New tank build... Large marine fish stocking/systems     4/14/14
Hi guys hope all's good, I upgraded my tank to 150 or so UK gallons or to you guys across the pond 187 US gallon's (60"x 30"x 24") about a year and a half a go but I have a few fish that I know will need a bigger tank in time, they being my Stars and Stripes puffer 7" and my emperor angel 5",
<Oh yes>
I'm planning on upgrading my tank hopefully by the end of the year to a 96"x26"x24" or 96"x30"x24" and was wondering would this size of tank be suitable for both these fish when they reach adult size?
<Yes; likely so... to some degree; though not as much as for most freshwater organisms; marine fishes can be stunted size-wise to their environmental limitations>
I was also looking to add some other bigger fish like the sailfin tang and maybe 1 other large angel but if that's not possible then no worries my main concern is that the tank I'm upgrading to would be able to house my two current fish for their entire life, I would greatly appreciate your expert advice on this.
<Welcome. Bob Fenner>

Emperor angelfish, sys. mostly    10/17/12
Hello guys, quick question regarding the emperor angel, i upgraded my tank to a 187 gallon (60 inch wide 30 inch high 24 inch deep) I purchased an emperor angel for the tank,
<Will need more room in time>
 a recommendation by my LFS, he's in with:
3 Anthias
2 fuzzy dwarf lions
2 green Chromis
2 clowns
& a stars and stripes puffer
<This too... and the Angel and Puffer may work the Dwarf Lions woe>
My question is would the emperor be ok in this size system,
<Not indefinitely, no... See WWM re the species System FAQs... needs a 300 gallon plus at larger size>
I got him a week ago, he is changing from a juvenile to adult colours and is around 5 inches, he seems really happy in the tank, he has a lot of space to swim and is eating well, also I was thinking of adding two Heniochus Butterflyfish to the tank, would they have sufficient space in my system?
<For a year or two>
 Any help would be great. Many thanks
<Welcome. Bob Fenner>
Re: Emperor angelfish   10/17/12

Thanks for the info bob, I knew the emperor angel would be ok for now but not in the long run but il trade him up when he starts to get bigger I just paid £100 pound for him so il give him a while, he's still quite small. While I'm here bob could you give me your thoughts on the blue stripe and the scribbled angelfish,
<I'd only stock one specimen of large Pomacanthid angel here at a time>
 I was thinking of putting both in my tank or one of the other but il go with the whatever you thinks best for my system and if not those two is there any of the larger angels you would recommend for my size of system that would live there for it's entire life?
<...? Whole other families... Tangs, Rabbitfishes, Goatfishes... many, MANY other choices. Peruse WWM re stocking: http://www.wetwebmedia.com/marine/setup/marsetupindex1.htm
 I also like the Pomacanthus navarchus but again I'll go with whatever you recommend, also what is the potential size of a stars and stripes puffer, will it reach it's massive 20 inch In captivity? T
<... please learn to/use the search tool, indices on WWM. These questions and so much more are already answered there. B>
hanks again bob.
Re: Emperor angelfish   10/17/12

Thanks Bob, I forgot to mention that I was thinking of putting either the scribbled or blue stripe angelfish only when I had traded the emperor, maybe in a year or so, I wouldn't put either of these fish in with the emperor I know it can be aggressive With other angels I just cant see what their recommended tank size is, but il start doing a bit of reading on the pages you provided, thanks Bob. Steve
<Real good Steve. Cheers, BobF>

Emperor angelfish, sys., reading   12/31/10
Hello Crew
I am going to get a 5x2x2ft aquarium would this be ok for a emperor angelfish to live its life
Thank you for your time
Callum Munro
<Better if this tank were longer... 6, 8 feet. Please search, read on WWM ahead of writing us:
and the linked files above. Bob Fenner>

Mis-placed Imperator Angel  12/12/09
Hi Crew,
Sorry to be a pain, I was chatting to bob recently about my blue faced angle that has sadly past on due to getting stuck in behind a piece of live rock.
Now I am in trouble with his replacement.
8 days ago, I was in my LFS looking for a new feature fish for my reef tank, the sales man sold me a rather large Emperor Angel (about 25cm) in length.
<? Was this fish collected at this size? Or did it grow up in captivity?
Large specimens of most all fishes collected in the wild have difficult time "adjusting" to captive conditions>
We talked it over at length as I was a little concerned that he was a) too big for my tank
<I see below your tank is 4 by 2 by 2 feet. This specimen is WAY too big here>
and b) would nip at my corals
<Might well do so>
and c) had read here that they are not so easy to keep.
<The "orange chested ones" from further into the Indian Ocean, Red Sea can be hardy, the western Pacific ones have a dismal survival history by and large>
The guy assured me all was well and he would be "the perfect feature in my reef tank".
<Take this animal back. Now>
Well "bertha" is the perfect gentleman when it comes to corals and never touches them, he eats the spectrum finicky fish formula that I feed, although he is not a ferocious eater, a little picky. He also seems to love picking at the Sushi sheets I throw in every now and then, and seems to be happy, but he is not looking healthy. He is going blotchy in the black under his belly and his eyes are just a little cloudy, he also spends a lot of time just sort of hanging over the live rock. Due to his size I couldn't put him in my "Q" tank and at first thought he might have ich, but for the life of me I can't see it even though he spends a lot of time with the cleaner shrimp on him.
<A transient infestation. Something is still there>
The water parameters in the tank are pretty much spot on. Ammonia 0, nitrite 0 nitrate 0, SG 1.024, Ph 8.1, KH 250, calcium 480, temp 25 Degrees C (Chiller installed) . Water is crystal clear , I use Ozone. Corals are all flourishing, wide open and fully extended, even my 12 Inch magnifica anemone is looking fantastic.
Other fish are happy and are very bright with no sign
of and ich (even the 2 blue tangs). But I am concerned that this fish has not settled in. I have read over your posts about these angles and saw that they are not considered easy to keep, but I thought that if the tank had good water quality and they were well fed with hiding caves etc they "could" be kept.
<Not in the shape or volume system as yours. A specimen of this size really needs to be in something at least twice the size... eight feet long>
There are several caves for him to hide in as well as he can get behind the live rock up against the back of the tank right out of site. I can't put my finger on why he is like he is. Would it be that he is too big
for a 4ft reef tank?
and that he is stressed at the tank size.
He has heaps of swimming room available. Any guidance would be fantastic. If he is not right for this system I will take him back.
<I would>
In saying that, in store he was in a 1/3rd of the size of mine and was fully coloured, swimming round looking great with about 5 other angels in the same tank.
<Can be thus crowded in short terms>
Setup of my tank
Sump with 5kg Matrix and 1 reef block ( supposed to filter 1000L on its
own), Polyfilter pad and filter wool.
Reef Octopus hurricane skimmer rated to 1000L with Ozone connected
2 x 4000LPH Tunze 6045 Power heads plus 2 x 1000LPH Aqua One power heads.
3500lph return pump on sump
150w 14000k MH x 2 plus 4 x PC Actinic Blue
60Kg Live rock in tank
3 Hammer corals, 2 leather finger corals, 1 Gorgonian fan, 1 Green tree coral and approx 15 mushrooms corals assorted
Tank mates
4 x blue green Chromis
2 x blue tangs ( 2 inches)
2 x 1 Inch long yellow twin spot wrasse
<Is this Coris aygula? If so it will get too large here... approaches 3-4 feet in the wild>
1 x Yellow tang
4 x Nemos, 2 orange, 2 black
1 x Juvi Koran Angel ( 3 inches)
1 x Foxface (2 inches)
<W/o the Emperor, your system is already topped off fish-wise. I would not add more fish life here>
Thanks again for all your help.
Jamie Illistom
<Feel free to show your stockist my comments here. I'd ask that they credit you for the Imperator. Bob Fenner>

Re: Mis-placed Imperator Angel   12/13/09
Done Done Done and thanks again Bob,
<Welcome Jamie>
I went through the first 12 months of Marine keeping without finding your website, hopefully this will be the last question for you.
<I hope not!>
I am about to set up a fish only 350L system, which is currently freshwater.
Hopefully this will be a smooth transition. Thanks to the valued resources on your site, I think I have a huge head start.
P.s. I now really owe you a good time in Sydney. Make sure if you want to dive our temperate waters, you give me a shout.
<I definitely will. Am a very keen diver, U/W photographer... as you'll hopefully see. Cheers from drizzly S. Cal., Bob Fenner>

Final Touches'¦120 FOWLR Stocking -- 05/24/09
First off, I have to thank you for your advice over the years.
<<Ah! Is quite the collective effort'¦and you're welcome!>>
I bought a new house 3 years ago that I decided to buy my dream tank for the dinning room and utilizing discipline and technique over spending hundreds of hours on your website I have been quite successful.
<<Great to know>>
I have a 120 Gallon, FOWLR system.
100 Lbs live rock.
Dual overflows/returns in additional to a Maxi-Jet aerator creating great water movement.
<<Hmm'¦you don't fine the 'aerator' to create excessive salt creep?>>
Sump underneath with NO bio-balls, but some activated carbon and general water filter pads.
<<And cleaned every couple days (at least), I hope>>
AquaC EV120 (great upgrade over my 30 gallon that had the AquaC Remora). Also a less than 1' sand bed that has never had a algae problem (kudos for the less than an inch or a DSB rule).
I have never really had a casualty in this tank as I am very picky on the fish I will put into it.
<<Mmm, yes'¦stocking selections and levels can make a huge difference in the success vs. difficulty of a system>>
Right now my stocking is:
1 - 6 inch Kole (Yellow Eye) Tang
1 - 7 inch Copper-Band Butterfly (this thing eats anything and everything like a shark.....pretty rare for the species.)
<<Much agreed here'¦ I find they are generally quite selective/picky feeders'¦often even favoring one 'brand' over another>>
2 - Firefish
1 - 4 inch juvenile Emperor Angelfish.
<<Mmm'¦ Likely fine for now'¦but you will ultimately need twice the space currently afforded to this fish. Have you read here and among the associated links? http://www.wetwebmedia.com/marine/fishes/angels/pomacanthus/imperator.htm >>
Cleaner Shrimp and a few snails/clean-up crew hermits.
I added them slowly over the 3 years and just recently added the angelfish. My tank relatively looks pretty empty with only the 4 fish until I added the emperor. I want to keep the fish long term,
<<Do research this fish more'¦and consider your feasibility of a larger system>>
really favor peaceful tanks,
<<Though hardly a 'peaceful' fish'¦I think this mix will allow the Angel to easily establish its dominance without too much harm'¦and'¦do keep all well fed to further reduce aggressions>>
low maintenance that accommodates a relatively under-stocked status than a pushing the limit status. So I am basically done adding fish.... The last thing I want to add is a little school of Blue Chromis.
<<I see>>
I am thinking 4-5 of these little guys to have a little neat school in the aquarium yet keep the under-stocked status. What would you recommend for the limit?
<<5 -- 7 should be fine here, for now'¦ I don't really consider your system 'under stocked' for the long-term with the Emperor Angel present. I also want to make mention that in the interest of a 'peaceful' tank do consider a better-tempered Cardinalfish species over the Chromis. Perhaps Sphaeramia nematoptera (Pajama Cardinal) or Apogon leptacanthus (Longspine Cardinal)>>
I would love to add a Naso-tang or a powder blue tang.... but I know how hard it is to keep 2 of them in the same tank alone with wanting to keep a peaceful and under-stocked status I have decided against it.............But what is your take on that? Risky move?
<<It can be done'¦with caveats. I have five tangs from four genera (including these two you just mentioned) that do quite well together'¦but they are in a display some three-times the volume of yours (96'x30'x30'). I'm thinking your system is probably undersized already in the long-term with the Angel present. I wouldn't exacerbate this by adding either the Naso or the Powder Blue'¦much less both>>
Please advise and thanks for helping me be a successful aquarist!
<<Happy to share my opinions Adam. Cheers'¦ EricR>>

Re: Final Touches'¦120 FOWLR Stocking - 05/25/09
In response:
1. With the Emperor Angel currently a juvenile, I have been told they tend to grow slowly and when it outgrows the tank it will be re-housed or sold.
<<Mmm, you stated in your first exchange that you wanted to keep the fish 'long term.' Have you ever considered the effects on such a fish from just 'growing up' in a too-small environment? Yes, the fish is likely fine for now'¦but at what point does the size of the tank become a factor re physiological and sociological development and health? Do you know? Will you know? More food for thought'¦'¦'¦.>>
2. With the current total setup, including the juvenile emperor do you think I could add another fish besides the 4-7 cardinals or damselfish?
<<Not if you wish to stay within the guidelines you yourself established earlier (peaceful tank, low maintenance, under stocked'¦and not pushing the limits)>>
3. When you say you don't consider my tank under stocked for the long term, I'm assuming your saying it is relatively under stocked for now, but the angelfish growing almost to a foot in length
<<Or more'¦some 18' in the wild (http://fishbase.org/Summary/SpeciesSummary.php?id=6504 )>>
could present a challenge to the under stocked status?
<<'¦is 'my opinion' it 'will' challenge this system, especially if/as more fishes are added>>
Please advise and thanks.
<<Happy to share'¦ EricR>>

Imperator Angelfish tank size  12/13/08 Thank you so much for your answers. I have several more questions, this time regarding the size of the tank I will require. The first 4 questions relate to the size of my tank As you remember, the fish I currently have/want are as follows - 2" Rectangle Triggerfish (Rhinecanthus rectangulus) - 2.5" Purple Pseudochromis (Pseudochromis porphyreus) - 3" Tomato Clownfish (Amphiprion frenatus) - 4" Imperator Angelfish (Pomacanthus imperator) - 3" puffer (I am thinking of getting the porcupine puffer). - 5-6" Blue Hippo Tang (Paracanthurus hepatus) - 5-6" Yellow Goatfish I currently have the first 4 fish, but do plan on getting the rest slowly. I currently have a 120 gallon (I thought it was 125, but actually it's a 120). The dimensions are 60" (length) x 18" (depth) x 25" (height). I am planning on getting a new reef tank and was considering getting a 72x24x24 tank. However, I think it would be better (for the fish) if I moved my current inhabitants into the larger tank and made my current tank into a reef tank. So my questions are as follows: 1) Is the 72x24x24 tank too small for the above inhabitants? I know the imperator angelfish needs a huge tank, but how huge? I realize that the ocean is probably the best place for this fish to be, but what is the minimum tank size you recommend? <Will be for the Angel in time... which really needs about twice this volume. The proposed tank will/would likely work for what you list for a year or two> 2) 72 inches is about as long a tank as I can get (maybe I can go for 84, but I prefer the 72 inch because otherwise I would have to move my furniture and that's a big no no for the wife). What if I got a taller tank (let's say 30 or 36 inches), would that make a difference? <Not height, no... but wider would be better> 3) Would it make a difference if the puffer I purchased was a dogface puffer (the porcupine might be too big)? <Would> 4) Would it make a difference if I didn't get the Yellow Goatfish, or since the Yellow Goatfish is a bottom dweller, it wouldn't really take that much space away from the other fish? <Not much> The following question is regarding my tomato clownfish: 5) Basically, my wife doesn't like it. She wants a yellow striped maroon clown. Do you think if I get the yellow striped maroon clown AND keep my current tomato clown, there could be peace in the tank? I know clowns don't get along (unless they are a mated pair), but will the size of my tank make a difference? <Would too likely fight in time...> Thank you so much. I tried separating the questions into categories as best as I could. The first 4 relate to the size of my tank, and the last question relates to tomato clownfish (and I guess indirectly to the size of the tank). Eugene <Bob Fenner>

Re: Imperator Angelfish tank size   12/18/08 Bob, thank you so much for your reply. I bought your book and have read pretty much every section. Also, just wanted to let you know that my wife has agreed to an 84 x 24 tank (as opposed to a 72 x 24). I have several short follow up questions if you don't mind. <I don't mind at all. Am happy to assist you> 1) Would the extra foot make a difference for the adult angel? <Yes> 2) You said the height of the tank doesn't make a difference, but the way I look at it is the more water, the better water quality. So I am planning on a tank 30 inches high. Do you think there are any cons to getting a tank that tall? <Mmm, can be, in terms of you getting inside to take care of such a depth, some aquascaping concerns, definitely the cost of building... but for looks, this height is definitely more pleasing to the eye, particularly with the greater length> 3) I am going to have to wait to get the new tank (at least a few months). How long do you think I have in the current 120 setup (assuming I buy all the fish I told you in my last email). <Several months> 4) You said a 72 x 24 x 24 tank would still be too small for an adult emperor. How big do you think the emperor would have to be before it outgrows an 84 x 24 x 30 tank? I can give up some fish if there is little space; it's just that it's hard to give up a fish once one has gotten used to it. <About three hundred gallons... minimum... for some sort of length of time, quality of life...> 5) My current 120 gallon looks rather empty. Although I didn't get all the fish yet, I assume the new bigger tank (262.5 actually) would look empty as well. I know it will take a very long time for my fish to grow and fill up the tank, but what do you think I can do in the meantime? <Mmm, some schools of smaller species... Like Chromis damsels, Anthiines...> Do you suggest buying some damsels and getting rid of them as my other fish grow or would the damsels cause too many problems? <Oh! No problem. This is what I would do> Sorry for all the questions. I think I have all the information I need. Eugene <Thank you for sharing Eugene. Bob Fenner>

Tank Aggression - Emperor Angel  9/27/08 Hello Bob and Associates. Thank you so much for your service. While I have never posted before, I have benefited greatly by reading your responses to others in the past. <Welcome to more active involvement> Today, I am concerned about my Emperor Angel's aggression. He is a changing juvenile we've had about 6 months. He has always been aggressive, but we recently (2 months ago) moved him and some of his current tank-mates (niger trigger, harlequin Tuskfish, eel) from a 56 gallon tank to a 120 gallon <Will need more room than this... twice or more> tank, along with all water, substrate, live rock and filer media. Thus, the new tank has always been cycled and stable. This upgrade was planned when we purchased this fish and was necessitated now by his development of lateral line disease, which we presumed was due to lack of space. <Indirectly, yes> He has improved and continued (right after the move it seemed immediate, but now it's slowed) in the change process, with yellow lines now showing, but the lateral line facial erosion is not completely gone (the body is still better). <Mmm, I take it you've gone over the HLLE section on WWM> The angel has always been aggressive, which I understand is the reason for its name. We were annoyed about him chasing the harlequin, but he is very fast, seems unfazed and no harm is done. The concern relates to a new addition (4 weeks) of a Naso tang. We love this beautiful new fish, which is about twice the size of the angel, but is not aggressive at all. The emperor is constantly biting at the Naso's underside (especially at feeding time) and we've seen some marks which seem to be the result (although the Naso moves away) and fear injury or undue stress, at the least. We are considering selling the angel, as a result, but would rather not if this may improve in time. <Mmm, not likely in the present circumstance/system size> I suspect that the angel simply needs to be the boss, <Bingo> so if that cannot be true he will not thrive and the lateral line disease will persist. <And worse> So, the question is - will an emperor angel 1) stop tormenting a newcomer in time, <Again, vanishing small chance> 2) become less aggressive with age <Not here> and 3) if this were your tank, what would you do? <Mmm, really... trade it in for something much larger, or... trade in some of the fish... likely the Pomacanthus> Thank you for you help. Carole <Welcome Carole. Bob Fenner>

Emperor Angel Living Quarters  4/4/07 Hi <Hello.> was wondering can I keep an emperor angel in a 300 litre tank <You'll have to forgive me being in the U.S. with that measurement...but I believe that to be very roughly 75 gallons or so, give or take? So the answer would be most likely; no. An adult angel of this genus/size would need a much larger tank...200 U.S. gallons or so....800-1000 litres on your end. Could be okay for a juvenile if tankmates a very minimal but not a long term arrangement for sure.> and also maybe 2 of them <No, one is pushing it....2 is not going to work, both with physical room and psychological room/aggression.> as it is only still young what would you  recommend <Adam J.>

A Question for Bob F, A personal sharing of job/life development, Emperor Angel sys.   12/8/06 Hey Bob, <Jeremy> Attached is an email that you responded to about a year ago. <Ah, yes. See, re-read> It is just now that enough has changed/happened for a worthwhile response.  A little over a month ago, I transferred upstairs to the environmental dept.  What I do is monitor the rainfall gauges and sample the water going through the storm lines.   <Interesting work...> The first time I went out in the field, I was conducting tests like Ammonia, pH, Chlorine, Copper, Fecal Bacteria, etc. and laughing to myself thinking about the aquarium and testing the water and how much I have already learned just by keeping a fish tank. <Yes>   When they tried to explain to me that the substance on a rock called Blue Green Algae is really bacteria called cyanoBACTERIA, I almost lost it.  My tank is finally rid of it too! <Good> I think I may have found what I am/was looking for (or at least on the right tracking to finding it) when I wrote you last December.  I asked you about Marine Biology.  For what it looks like, the major I was seeking was Environmental Biology / Conservation.  Any particular thoughts on this field? <A growing focus, need for general and specific understanding/progress> Some of the stuff I see out there is really something (in a negative way).  Sometimes just flat out insane...  At least now I feel like I am part of the solution.  I know I can't change the world, but I can do my part to help out.  It looks like I will be working upstream from you keeping as much crap from going into the ocean as I can.  I am starting on a project in the Port of Houston, so I will get a little bit of marine experience in.   I was in a wedding on the shore recently and I sampled some water.  Not during the ceremony, but afterwards and after I changed out of the tux. Just in case you were thinking otherwise...  I used some empty Ozarka bottles and people looked at me like I was crazy, but oh well. Surprisingly, it was ok.  The spg was at 1.021, pH at 8.2, Amm, Nitrite were at 0 and nitrate at 5.  What should I have been looking for in terms of pollutants that may have killed my fishes if I had dumped it in my tank?   <In the way of classes of chemicals? Metals, organic compounds of various sorts, saponifiers, pesticide residues... the topic is vast> I didn't want to risk it and dumped the water in the front lawn.  Are there any test kits I can buy from the LFS to test it? <Doubtful... Please see Hach, LaMotte websites... Perhaps Aquatic EcoSystems as well... Really, a trip to a/the library is in order here... CRC Press has some very good "standard works" on the topic of water quality...> Now on to other things.  Recently I wrote you about general advice in planning for a bigger tank.  Will an emperor angel really outgrow a 210 gallon system?  (If he does, he becomes dinner) <Yes, it really will> That's it for now.  Take care, Jeremy <I look forward to your further sharing of your unfolding (evolution in its true meaning) personally, career-wise. Bob Fenner>

Imperator Angel/Angle Let's see if you guys have ever run into this one. I have had this imperator angle since he was a juvenile and now is almost through his adult color change. So I have had him for about six years or so. Always has eaten well, good appetite. He lives in a 130 gallon tank with two triggers and he is the ruler of the fish tank. Everyone gets along and no fish wars here, no tail nipping, nothing. We have a few pieces of live rock with some algae on it and other small non-descript critters that the triggers cannot heat. Also have a sandy bottom with some tube worms living in it.  Over the past year and a half or so I have noticed the classic symptoms of hole in the head disease progression with this guy. I have put vitamins in the food, have always used a varied diet, and have always had good water quality as evidenced by the other two fish and the various invertebrates that live there.  Lighting is via 4 4' florescent tubes, two day light spectra and the other two combo actinic/white. Water changes once every month or at the most two months.  Here are a couple of things I found wrong in the last several months. I took some water samples into work and found my pH to be down around 7.5. I brought that up over the next couple of weeks with carbonate buffer to the proper range. That is when the tube worms started to show up in the sand. I also added on of those grounding probes to the tank as well, although I am skeptical of that. I started feeding more algae to them as well and he eats the majority of it.  Well, things have gone from bad to worse. The hole in the head progression seems to have gotten worse, but now this guy has a lump under his dorsal fin that is pretty big. The fish is about 6 inches long and 4 inches tall. Now picture taking a ball about 3/4" in diameter and putting it mid fish right under the dorsal fin behind the head. He looks like XXXX.  Appetite is still fine and he continues to rule the tank so whatever it is does not bother him enough to change his attitude. I suspect its a tumor of some sort and chemo or radiation is likely not an option. Everyone else in the tank is still looking fine by the way. Any suggestions? Phil Barnhart <A few... your tank is too small for these fishes... your water quality could be improved by having a better skimmer, doing more water changes... but you need a bigger system... Even if you're just going to keep the Angel... Do read on WWM re HLLE, the species you're keeping. Bob Fenner> Imperator Query More Q's, and thanks for all of the previous info. We are interested in setting up a tank for a Pomacanthus imperator. I've had several tank sizes recommended to me as well as reading about different tank sizes in several books. I've read and been told any where from 100 being the min up to 500gal. A 100 gal. seems kinda small for a fish that can get sooo big. I don't have room for a 500gal. in my house, do I need a bigger house? :) I wouldn't be surprised if I did, LOL. This has left me uncertain of what size I should purchase. Also, we are setting up a new sump for our old 100 gal FO. The tank has been moved to a spot where we have to put the sump in a closet on the opposite side of the wall behind the tank. We were thinking about using a shelving rack in the closet. On each shelf would be an 27 gal. Rubbermaid bin. Each bin would have something different in it, one would be a DSB, below that would be a bin with macro algae, LR and so on, each being gravity fed starting from the over flow box and down through the consecutive shelves then pumped back up in to the tank. Does the crew see any problems with this type of set up? Thanks again, SHAUNA >>>Hello Shauna, Pomacanthus imperator reaches an adult size of 15" or so in the wild. Captive specimens tend to top out at around 10 to 12" usually. However it takes some years for them to get anywhere close to this size. This is still a large fish though when eventually it does attain these proportions, and considering how active it is, say compared to a grouper of the same length, we need to consider it's space requirements. I think Scott Michael tends to err a bit in favor of the aquarist for his minimum tank sizes in a few places, if that's the book you're referencing. A great book, and he knows his stuff. I just think his minimum tank sizes need to be bumped up a bit for some of the large fish, especially for some of the larger angels. I would say that long term, you shouldn't consider any tank smaller than a 180 gallon. They grow at a slow, steady pace, so If you get a juvenile, it will live in smaller quarters for several years (say a 120 gallon) before you need to upgrade his tank. Ideally, I'd say purchase a 240 or 300 gallon tank (or larger) if you have the means. Regarding your other plans, aside from weight considerations and the need to have VERY strong shelves - sounds good for the most part. I would however question the functionality of such a small DSB in any system, let alone one this large. Regards Jim<<<

Imperator Query - Part Deux Thanks for the input. I'm thinking I need to wait to set up the Imperator system. I have space for a 200gal. max. Or, we may just wait until we get our new home in a year and get a larger tank since we'll have the room then, if everything works out like we have planned. I'm thinking we'll do the latter, that way we won't stress out the juvi in the move. That will definitely give us enough time to research the system and the fish thoroughly and more $$$$ to buy something larger than a 200gal for this little giant. A couple of other Q's. There is a pair of golden striped maroon clowns that has been at one of our favorite LFS's for about a month. They have hosted in 2 large bubble tipped anemones (side by side). With the plans for the imperator we were wondering if the clowns and their anemones would be able to hold their own in with the imperator? Also, I was recently told that as long as what ever fish a person adds to an imperators tank is a few inches smaller or more than the imperator, they should co-exist with out much squabbling. From what I've been reading, here and in the books, this doesn't sound quite right especially since this fish gets more aggressive as it matures. I'm actually hesitant to put any tank mates in with it since it could get pretty aggressive towards them. What is your take on this statement? I was wondering if they meant while it was juvi.  That's what made me wonder about the intro. of the two clowns above. Others seem to have had luck mixing other fish with an emperor. Or is it just that, luck, hit and miss, with fish being individuals and all? As for the sump questions, the shelving rack would be a steel one rated for more than what we would be requiring of it. Good point about the DSB, I'll have to increase it. I'm glad I run things past you all during the planning process, you all are great at catching stuff I miss, thanks. Shauna >>>Hello again Shauna, It's my pleasure, glad to be of some help to you. :) Keeping other fish with P. imperator is no problem at all, they're really not THAT aggressive - relatively speaking. Sure, he'll be the boss of the tank most likely, but he won't pummel his tank mates to death. When adding other fish, he'll be more likely to ignore fish that are smaller than he is, but they usually don't put a great deal of energy into persecuting tank mates regardless. Color patter is a bigger consideration than relative size. The main caveat in this regard is other angels, but I don't think you're planning on keeping other angels with  him anyway. I currently keep a sub adult imperator in a reef tank with the following - sixline wrasse, Foxface, Brazilian Gramma, orchid Dottyback, 7 Chromis damsels, snooty Maori wrasse. He doesn't bother a thing normally. As long as some common sense is used, keeping other fish with an imperator is no problem. Also, they shouldn't bother host anemones. I have 6 of them, and the imperator leaves them alone. Few fish will mess with host anemones. I have a pair of gold bar maroons in my tank currently, and in all the years I've been doing this, I think this is the COOLEST thing I've been able to observe in a tank. If you're going to move in a year, don't bother with a large tank yet. Moving a tank is HARD WORK - the worst part about moving. I wouldn't even consider setting up a tank yet if I were you. Cheers Jim<<<

Emperor Angel Hello - I have a question (mostly) regarding an emperor angel. I have a 75 gal FO tank, set up for close to two years, with an Eheim 2217 canister filter and an AquaC HOT protein skimmer. I change about 9-10 gal per week using RO/DI water. I have 4 fish: a 4-5 in. emperor angel, a 3 in. Picasso trigger, a 2.5 in. clown trigger, and a medium (3-4 in.) yellow tang. The emperor is the newest fish; I've had him about 14 months. He has been a great fish, rules the tank and eats well. I feed Nori and dried red algae every morning, and different frozen foods (angel formula, prawns, formula one and two) soaked in Zo?at night. Water quality seems ok (nitrate~10, nitrite=0, ph~8.2, sg ~1.02, temp~79 deg F). BTW, I previously had trouble keeping ph above 8, but it seems much better after adding the skimmer six months ago. The emperor has been changing for most of the past year, and is closer to adult than juv. For several months he has had occasional blotchy patches on his skin. They look like a loss of color in small to medium areas (biggest being 1/4 in.). They can come or go within an hour (sometimes look bad, then are completely gone). Is this part of the transition from juv. to adult? << Often times yes.  I would just watch water quality (keep the skimmer on) and make sure he has that varied diet you described. >> The triggers don't bother him at all. If it is likely water quality, what aspect? << I would check your alkalinity levels.  >> A bit higher ph may be good, but I already use baking soda weekly and change LOTS of water. Any thoughts would be appreciated. << Please do test alkalinity.  Also, when adding baking soda to your water, it is important for it to be thoroughly mixed, and added to the main tank slowly. >> Also, I have a problem with slime algae (which was present, but went away after switching to RO/DI water about a year ago, but recently has come back). << I usually see this in tanks which lack water motion.  I would consider increasing the water flow in that area. >> Thanks in advance - I really appreciate your help! <<  Adam Blundell  >> George

How big is big (Emperor Angel) and cleaner shrimp tankmates  12/12/03 Good Evening- <same to you!  Adam here by the way.> I have an adult Imperator Angel, approximately 6-7" long, that I've had for 4 years, having raised it from a juvenile.  When I first got it, I had it in a 125 FOWLR, but after reading Bob's advice, bought a 180 where it has been for the last 2 1/2 years. <Congrats on your success with this fish, and kudos for having the dedication to upgrade it's home!> The tank has about 125# of LR, with 7 assorted and much smaller tankmates.  While I have no desire to get rid of him/her, how will I know if it's outgrown the tank?  It does seem very happy and is doing quite well. <You have largely answered your own question.  After four years, you know your fish and your success is a clear indication of your skills.  As long as the fish isn't showing signs of stress, I wouldn't worry too much.  As your fish approaches it's full grown size of 15" or so, you may have to remove some live rock to improve swimming room or start thinking about larger quarters again, but that should be a while down the road.> At some point, will it stop growing and just maintain it's size based on the tanks size or can I expect it to continue getting bigger? <You have fallen for the oldest and greatest fish keeping myth.  Regardless of tank size, fish will continue growing until they reach their natural full grown size unless water quality, nutrition or disease enter as limiting factors.  You do have some time though as most fish grow more slowly as they get larger.> Thanks for the advice.  I couldn't think of how to do a search in the archives, or I would have started there. <always a pleasure.> Are there some fish that don't get along with cleaner shrimp (Lysmata amboinensis)?  I have had quite a few disappear over time and have always thought it was the angel, however during the day it seems to leave them alone if they are out cruising around.  Other possible candidates are maroon clown or hippo tang? <Any predatory fish could potentially turn on a cleaner shrimp, especially if they get a bit too hungry, and all of the fish that you mentioned could be suspects.  If you only had the shrimp for a short period of time, I would look to poor handling or rough acclimation first though.> Andy

Juv. emperor angel Hey guys, <Whassssupppp?> I have a juvenile Emperor angel in a 92 gallon corner bow front. He has been very happy for the past year and he's now about 3 and a half inches. I was telling my wife that we need a huge tank for him, but want to know approx. how long you think he will be ok in this size? <tell your wife that even though I haven't met her, I just know that she is a wonderful and empathetic person. Oh, and that Anthony Calfo says you need a 240 gallon aquarium for a 12" adult emperor angel. Hehe... and I'm serious. If you will have this fish and little else though in the 4-7 year picture, a six foot tank will be satisfactory (125, 150, 180 gallon). Best regards, Anthony> Thanks, Ken

Tank size requirement? I want to setup a small tank in my office (controlled environment) with 1 Imperator Angel. What would you recommend as the minimum tank size, <A 90 gallon tank.> I currently have a 30 gallon tank that I would like to use. <Not for an Imperator.> This will be the only fish in the tank. <Still needs room to swim.> Thanks, Craig <You are welcome. -Steven Pro>

Emperor angelfish Hello, My name is Alena and I have been to your site many times. <<Hello to you.>> But have not found an answer to my problem. I have a 55 gallon tank that has been up and running for about 5 years now. Really haven't had any problems with it until now. I have a yellow tang, maroon clown bonded to a bulb anemone and a saddle puffer. I just recently got an juvenile emperor angelfish, which has been doing fine for a week now, but it looks as though it has a white pale coat, spread evenly over his body. The emperor eats, and acts fine, but he/she doesn't use its back body to swim (like he/she is stiff or paralyzed). It basically swims using only his/her side fins, but still swims around the tank like a normal fish. The emperor doesn't have any parasites on him/her, and I have researched many diseases on the internet that doesn't match what he/she has. The emperor has been like this for about two weeks now, and doesn't look like it has been getting better or worse. Now, I pulled the emperor out of the tank and put it in a QT tank that has been running for about two months, and treated it with CopperSafe to make sure parasites, that I couldn't see, were not the problem. He/she has been in the QT tank for 4 days now, but still the discoloration and lack of movement in the body still exists. I don't know what it might be, if you have any ideas what I can do please let me know. Thanks, Alena <<Alena, what I think you are observing is two things... one, these fish often swim like this, saving the caudal [tail] fin for a mad-dash to cover. Two, I would hazard a guess that this fish just doesn't need to swim that hard... a 55 is really much too small for this fish, and likewise you may not have extreme currents in the system. Although it is small now, they grow to about a foot and I've seen these where they live - they get BIG. So... it's probably not very exercise challenged. I would skip the quarantine, consider another powerhead for the tank and start saving for the 240. Cheers, J -- >>

Size of Fish per Size of Tank I have a 75g reef system, and just love emperor angels. I have a chance to get a small Red Sea juvenile. I'm wondering how long it would take to outgrow a 75g before I can move up to a 125g tank? Can an emperor survive in a 75g tank permanently? <He would probably be okay for about a year.  It will not be able to live in there long term as they can grow to be 16".  Cody>

- The Emperor has no Space - Hi Guys, <Good evening, JasonC here...> I have received good advice from the crew in the past and hope maybe you can help me with my current problem. I have an Imperator Angel 6" adult in a 90 gallon tank, I know this is small for this fish, but house is too small for bigger tank, I also have a 125 gallon community tank. <This fish should really be in the 125...> My problem is that the Imperator has large faded white spots all over it's body, I treated with Copper Safe and after 4 days the spots went away, I kept the copper in the 10 days as suggested then started to pull it out with copper remover, poly filter and water changes, within 2 days the spots started to reappear and are most noticeable in the morning and less at night. I then suspected that maybe it is a vitamin deficiency so I give the fish Nori algae every day and at first it seemed to work, the spots went away, I really thought I solved the problem, but within 2 days the spots came back. My nitrates are not terrible for a fish only tank 20ppm, I don't know what to do next, any advice would be appreciated. <The white spots are typically caused by water quality issues, but can also be a general indicator of mood, as in the fish is not happy in it's current surrounds. These fish get much larger that this and are used to much more room to roam. I would look carefully into collateral damage from the copper treatment, as it typically stalls out biological filtration. Do a couple of decent-sized [25%] water changes and go from there.> Thanks Fred <Cheers, J -- >

- Baked Emperor - Gentleman, <Good morning, JasonC here.> I have an Emperor Angel.  He has been fat and happy since the day I bought him.  Has just started to turn colors and has stopped eating and is quite lethargic.  I don't know what is wrong.  Water parameters are good although the temp gets to around 88 this time of year due to the heat and humidity.  Any suggestions?? <Yeah, do something about that temperature, it is much too high.> tks John Cape Cod <Cheers, J -- >

Quick Question Hi Bob. About a month or so ago I wrote you about my 110 gal all fish setup, which has now been setup for 3 months. At that time I had a 4" juvenile colored Imperator Angel and a 2.5" cleaner wrasse. I'm happy to report the Angel is doing GREAT, totally disease free, very active, brightly colored, and accepts 7 different kinds of foods!  <Ah, good news> The cleaner wrasse is great, too. Just last week I added a 3" gold-rimmed Maroon clown, and (against your advice, but I couldn't resist trying) a 2.25" juvenile Atlantic Rock Beauty (Holocanthus Tricolor). At first Mr. Imperator bullied him, but the Rock Beauty is such a pesky little thing that he wasn't daunted, and he feeds great and is VERY ACTIVE, and now the Imperator has JUST ABOUT accepted him fully in his "kingdom."  <Wowzah, very surprising and good news> I'll probably add a few butterflyfish and either a Red Sea Purple or Sohal tang, and that's it. <Probably about all the 110 can handle for now>  The Emperor still dominates my tank, and above all, I want him to continue to grow and prosper. My question is, what is the max size you think a 4" Emperor can or will grow to in a 110 gallon tank? <About eight inches... which can be pushed into about a year, but will be much better to drag into two, three... until you can offer it larger, better quarters> Dimensions are 30" H x 18" W x 48" L. I'd like to keep him in this tank until he's 8 or 9 inches, and then move him to a bigger 150 or 180 gallon, which I'll probably buy next year sometime. Also, how long do you think it'll be until this fish reaches the aforementioned 8 or 9 inches? <As stated... a year or more depending on feeding, other factors... will be much happier, healthier in a larger system> As always, thanks for your advice. One of these days soon I'm going to pick up your book on Marine fishes, I hear it's pretty great. <Me too> Regards, Scotty Knight, Erie, PA >> <Bob Fenner>

Juvenile Empower Angel Bob, As you responded so well to my last e-mail of sometime ago, I am writing to you on another subject - namely that of the swimming condition of my J.E. Angel. He is about 5" long and still very much in his juvenile state and lives in a 60UK G fish only tank with live sand and external wet & dry filtration. Skimmer is a SeaClone as I have not changed it yet but will hopefully soon. His body is OK with no markings or sores etc, however he is swimming very "awkwardly". When he swims upwards he uses "all" his body to propel himself - that is what it looks like and he also seems to be spending a lot of time by the skimmer pump inlet. He is not caught by the pump as he can swim away quite well - maybe he likes it there? <Maybe... does it ever swim "normally"?> He is feeding OK with frozen brine shrimp (1/2 a cube a day) + flakes + a square of algae sheet. I have had him some 5 - 6 months and he has only been like this for the past month or so, before that he was fine. The water parameters are fine - checked last night - pH - 8.6 (always has been), Ammonia - 0 , Nitrite - 0 , Nitrate - 20 & Phosphate - 0.25. Any thoughts would be welcome. Best regards, Scott PS - LFS has stated that my wet & dry filter (Eheim 2329-85) would overcome the usefulness if the skimmer and therefore it would not be necessary to change the skimmer as it would not pull anything out! Any response?? >> <Don't understand the logic behind/in front of the above stmt... and disagree with same... the SeaClone is a gimmick... and you will definitely see more and worse/better "gunk" removed via a real skimmer... with or w/o a/the wet-dry... Re the angel, something may be amiss (evidenced by its swimming), but... as to cause/cure? A genetic, developmental anomaly? Lack of nutritional component? Some aspect of metabolite poisoning? Many other possibilities... I would use activated carbon once a month, get/use a better skimmer, and vary the diet... Bob Fenner

Re: Advice Bob: Great website! I have been looking for something decent, the Emperor FAQ was quite useful. These fish (emperors) act very funny with their antics. <Yes, very intelligent fish> One more for you. I have a 95 Reef Ready tank with the following: Adult Emperor 5" Asfur Angel 2.5" Lemonpeel 2" Flame 2" Adult African Clown (formosa) wrasse 4" Sixline wrasse 1.5" mixture of corals (dead) and 6-7 pieces of live rock (lots of hiding places). 25 watt UV and Skimmer. I know that this tank is stocked up to the max at this point, any comments? <Umm, total agreement with your stocking assessment... as of now, and a caution that you are going to need a much larger system soon (let's say three hundred gallons plus) or to trade in the Asfur in a year or so, and then the Emperor... Bob Fenner> Thanks again for your advice. Chris

Pomacanthus imperator Hi Bob. I really enjoy and appreciate your site. I was wondering why there was nothing like this on the net and then I found your site last week. Excellent!  <Great! Glad we found each other> Here's my question: I have a juv. emperor angel. I've had him for about a year now and he seems to be making good progress towards his adult coloration. Is it normal for a captive specimen to develop a normal adult color pattern?  <Yes, over time... sometimes with not much growth> I seem to remember reading once that captive juveniles rarely attain full adult markings. Is there anything specific I can do to encourage or assist the change (specific foods, supplements, etc.)? <Hmm, nothing specifically... Keep up regular maintenance, use live rock (replacing some every year or so), providing a mixed diet... possibly enriching same with a vitamin and iodide adjunct... Bob Fenner> Thanks. Again, great site!

Angelfishes for  Marine Aquariums
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