Chromis aggressive - 07/19/08
We have four green chromis and two purple (look black) Chromis. We've had them all for over six months, no problems with them or with the other fish. All of a sudden one black chromis is continually chasing the other black one, they were both added to the tank at the same time when they were small.
Is this an indication they might be wanting to breed, or?? One has the other hiding to get away from it.
Marilee
<Mmm, though, amongst Damselfish genera, species, Chromis tend to be "more mellow", there are individuals who are at times quite aggressive... Particularly when kept in too small settings, in too small groups... I'd likely trade in the more agonistic one here... unless you have room, desire to add several companions. Bob Fenner>

Blue Green Chromis, sel., sys.   3/10/08
Hello Crew!!!!! Okay, here it goes. I have a 55 gallon reef tank with some mushrooms, leather, zoos, and polyps. Currently I have 10 Cerith
snails, 5 Astrea snails, 2 tank raised common clowns, and a lawnmower blenny. Also have about 70-75 lbs of live rock. Readings are as
follows: pH = 8.4, Nitrates = 5-10 ppm, Nitrites = 0, Ammonia = 0
<<All looks fine>>
My question is............I REALLY want a school of blue green chromis.
I was thinking 5 or 7. If this is all I put in my tank (other than what I already have), do you think it is possible? If not how many, and if
none, what else would you suggest?
<<Due to tank current stocking and size, 5 is the maximum i would go for...On that note though, i have always felt that Chromis do school better in numbers larger than 5... Don't know if that will influence your decision..>>
<<Other suggestions would be goby's, blenny's, Firefish>>
Thanks for all of your time and hard work. This site has helped me learn more than you could ever imagine about saltwater and reef keeping. Thanks again. Matt
<<Thanks for the question. A Nixon>>

Stocking question: Chromis in a 36G  3/2/08
Hello,
<Ron>
I have a stocking question on my system.? It is a 36 gallon aquarium (Tunze Nano skimmer, Emperor 280) that has been up and running for 8 months with the original inhabitants (1 small red legged hermit, 1 True Percula Clown), a few Nassarius snails and a Camel shrimp.? I have converted over from the original crushed coral to a shallow aragonite sand substrate and am switching over from the original red lava rocks to some Marco rock dead rock and will add live rock in the near future. I have recently acquired a small QT tank (12 gallon Eclipse) that has just finished cycling using a frozen shrimp.
Looking for a new addition to be a peaceful, colorful and active addition.?
I was considering a pair of Blue/Green Chromis as I like its attributes, but then began reading.? I believe three is too many for a 36G system, two is not preferred as odd numbers seem better to divide up any aggressions and a single one does not seem the best either for they prefer to be in numbers.
<Is really too small period>
Which of these (1,2,3) is the least of the evils, or would I be better off passing on the Chromis and going with another route?? Overall I will look for 3-4 fish total for the system, and would like all to be reef compatible should I eventually add a coral in there.
<Mmm, depends on the species... I would avoid C. viridis et al. large number in schools types... Perhaps some more solitary Chrysiptera genus would be better...>
Some others I am considering are: Royal Gramma, Firefish Goby, Fridmani Pseudochromis (although these seem pricey).
<Please read re on WWM...>
I would appreciate any suggestions you could make to the Chromis plan or another peaceful/lively combination.
Thanks,
Ron???
<Enjoy the research. Bob Fenner>

Purple Chromis  -02/20/08
Good evening crew,
I was wondering if you guys know anything about Purple Chromis, Chromis scotti?
<<Chromis scotti is correct>>
The pictures I've seen of them are beautiful, but I can't find any good information on them.
<<Basic info for you here then...A nice peaceful fish, very much the same as the normal chromis. Grow to about 4 inches, feed on meaty foods, frozen preparations and foods of that ilk. Adding good vits to the foods. As with other Chromis, best kept in a school, but can be housed as a single>>
Would one of them do well in my twenty-nine gallon reef tank?
<<Yes, you could keep one in your tank>>
Thanks in advance, Brandon
<<Thanks for the questions. A Nixon>>

Green Chromis – 1/26/08
Hello,
In my tank I have a school of Green Chromis. I want to add some more, but I heard that the existing fish in the tank will fight and kill the newcomers.
Is this true?
<Mmm, a possibility... given enough room though... not necessarily>
Is there anyhow I can avoid this problem?
<Ways you can reduce the likelihood... Rear in a "parallel" system, moving some water back and forth weekly... till the new specimens are large/r, healthy... move all over to the one display during the "just dark" period of the night...>
I don’t want to wait for all of the existing chromis to die before I add more fish.
Thanks for your time, Aly
<Please make your progress here known. Bob Fenner>

Urgent marine advice needed. so many mistakes, so little time... Chromis... – 09/08/07
Hi guys/gals,
I've been up all night reading through your FAQs, and I've got myself in an awful tizzy. Apologies in advance for the very long email, but I want to make sure you've got as much info as possible
Background (please don't yell at me):
My partner and I started last October with a 60L tank (15Gal), FOWLR (+ Hitchhikers - crabs, pistol shrimp). Our only fish was a Valentini Puffer (Puffy- yeah, i know, original!)-
<Needs more room... Oh, I see this directly below>
we shortly realised that the tank was too small for her, but have only now been able to upgrade. The tank was also getting an anemone infestation due to Puffy's messy eating and inadequate filtration.
So, start of August, we bought a 220L (55Gal) Cube (AquaOne brand), and intended to use our 60L as a quarantine.
<Better...>
The tank has crushed coral sand and a Jaubert cavity, and the filter/ sump is an AquaOne Marisys.
We have about 23kg (~50 pounds) live rock, which was bought in 2 halves, a week apart. It had been cured at the store, looked and smelled healthy. Puffy was moved over within a couple of days of the 2nd set of rock being added. Ph was 8.3-8.4, Ammonia and nitrite were 0 and nitrate was 10ppm at the time.
<Good...>
The following weekend (mid august), I was away, and my partner purchased 3 hermit crabs, and a cowry.
<Mmm, food>
(Puffy has never shown the slightest interest in the crabs in her old tank, and is an incredibly good natured fish). The following day, he purchased 4 blue/green Chromis, which had been co-habiting a tank with another, larger, valentini. The idea here was to acclimate Puffy to the presence of other fish, as she'd been so long without company. He put the Chromis directly into the main tank, as the quarantine tank had not been set up (still had the old live rock in it).
So, the Problem(s):
After putting the Chromis in the tank, 2 developed bruising.
<Likely, oh, I see this below as well>
We figured that this might have been to do with their violent reaction to being netted, but thought we should do our best to quarantine them anyway. So the quarantine tank was prepared (or so we though), and the Chromis were once again caught, and transferred.
A couple of days later, and after some evidence of bullying, one of the Chromis with the bruising started to develop rapid breathing and stopped eating. We checked the water and there was 1.0ppm Ammonia. we did a water change (mixing our own from tap water... yes, i know now...), and it didn't help. Eventually we checked the tap water and to our horror found that it already had ammonia in it.
We freaked, read all about chloramine, and went back to our LFS to pick up some sea water. But we also moved the Chromis back into the main tank (we'd had them for a week by this stage), thinking that it would be better to get them out of the ammonia.
The fish exhibiting breathing problems lasted another couple of days, but then we found him dead one night. The other fish (including the other bruised one) seemed fine. When we extracted the dead fish, I examined the body, and it did indeed seem that the bruise was in the same area as some missing scales (and therefore probably caused by netting trauma). That was about a week and a half ago.
A couple of days ago though, another of the Chromis started showing breathing problems, was hiding behind the rocks, and wouldn't eat. He was also being bullied a bit by the other two, (who regularly have their dorsal fins raised, and seem also to be butting tails with each other a lot). Water parameters were 8.3ph, 0ammonia, 0nitrite, 15nitrate. We found him dead this morning. I couldn't see anything particularly wrong with him (there were a couple of darker scales, but they were fairly consistent with night time colouring).
So, I've been reading through your chromdisfaqs page and came across a disturbing possibility that this is Velvet (see 3rd from bottom). I haven't noticed any of the fuzziness associated with it though.
<Is not Velvet... I assure you... if so, all your fishes would be dead>
The other 2 Chromis are fine... so far, but then again the 2nd one only started having problems after the 1st one had gone.
Solution?:
As horrible as it sounds, my main concern is Puffy (obviously I don't want the remaining 2 Chromis to die either, but if it comes down to the choice... ). The only thing is, I don't know what to do about it.
I thought about moving her to the QT, but if it is velvet, then presumably our QT is also infected from the week that the Chromis spent in there (I assume it would also be in all the filter material, so to clean it out we'd essentially have to start with a completely un-cycled tank (new water, new filter material, no live rock/ substrate)). I also don't want to risk treating the QT with copper with her in there (I've read on WWM that it can be done with puffers, but that it's risky), but due to the speedy nature of the problem, would want to act ASAP...
Also, if it's not velvet, and is just bullying, then we'd be putting her through unnecessary stress, and back into a small tank that we don't have any good way of keeping good water quality in without any liverock...
Please help!
(I don't know if you normally reply by email, or just post onto the site, but if possible, could you please reply by email so I know as soon as you've replied?)
Thanks so much
-Jo
<We do respond to all directly... I fully suspect as you state that the larger part of the source of mortality with these damsels is/was trauma... before you received them. Some batches of Chromis do "just die" easily... likely resultant from the vagaries of collection, holding, shipping... and your system is very new... and not really large or a good-shape for these Damsels... I would NOT treat the tank... Nor really add any more Chromis spp. Do wait a couple of weeks... and re-formulate a stocking plan, chat with your stockists... Cheers. Bob Fenner>

Sending Chromis To School (Schooling Size) – 07/18/07
Hello,
<Hey there! Scott F. back with you tonight!>
I have a cycling 86g tank that I plan on stocking with a pair of Maroon Clowns, snails, a BTA, and Chlorodesmis fastigiata.
<Sounds nice!>
I'm currently looking at schooling fish and have my sights on Chromis acares, Chromis viridis, and Chromis vanderbilti. I'm trying to create a biotope aquarium, so I want to know how small their schools/groups/shoals can become in the wild, i.e. is it common for them to swim in groups of 5 or 6?
Thanks in advance, Random Aquarist
<Well, Random- I'm looking forward to seeing this biotope come to fruition for you! Chromis are usually found in shoals, sometimes numbering hundreds of individuals. You can certainly keep them in small groups of 5 or 6 in captivity. However, in captivity (as in the wild), dominance hierarchies may develop, with the subordinate members bearing the brunt of the dominant fishes' aggressions. Often, aquarists will start out with a number of individuals, and the population will dwindle to a couple, or even one fish. I've seen the best successes with Chromis atripectoralis (The "Green Chromis"). It's not the nicest of the bunch, but it is a beautiful fish in its own right. It does reach a larger size (like 3-1/2" to 4") than some of the other members of the genus, but it seems to do better in groups. I've seen a large (180 gallon) reef system with a shoal of 12 or so of these fishes, and it was beautiful. The aquarist had made many attempts with other species, yet finally achieved lasting success with this species-the shoal is still going strong after 3 years! Do consider this species and see if it works for you. And please keep us posted on your progress with this system! Go biotopic! Regards, Scott F.>

Atlantic Blue Chromis (Chromis cyanea)  4/14/07
Wet Web Media -
<Mmm, is this the person who was chatting with Morgan Lidster... (Inland Aquatics)... He and I talked on the phone yesterday re this species...>
I have a question concerning the mortality rates of the Atlantic Blue Chromis.  I have designed and setup a 90 gallon reef tank as a niche biotope to the Northern Gulf of Mexico.
<Neat>
The tank was setup a year ago and invert and sponge growth has been great.  The rockscape will feature large boulder type layouts and will feature 3 Pacific Montastrea corals, a couple of Porites and a lone Gorgonia.  One of the Montastrea's is farmed and I was able to acquire 11 frags from the same mother colony to simulate one coral dominating the area, with the others scattered in to give some color and texture.  Other inverts would be the Orange White Claw Hermit (C. tibecins?), Coral Banded Shrimp pair and a dozen Cerith snails (they should breed to a stable population up or down depending on the algae available).
The fish plan was to feature a pair of neon gobies and a school of 7 blue chromis (C. cyanea).  All my research on the web and in books indicates everything should be okay and my biggest problem will be that they may not school once comfortable in captivity,
<Perhaps in time...>
not a concern to me.  However, in looking for a source to purchase these fish, I am finding that they are in fact difficult to keep.
<Mmm, yes... I think this is mainly due to the fact that this fish is poorly handled post capture/collecting... but it also does not adapt easily to captive conditions>
  This is the first I have heard of this and I see no references to this, not even on this site.
<Mmm: http://www.google.com/custom?domains=www.WetWebMedia.com&q=chromis+cyanea&sitesearch=www.WetWebMedia.com&client=pub-4522959445250520&forid=1&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3A99C9FF%3BLBGC%3A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A1%3B&hl=en>
What are the issues with keeping these fish?
<This fish? As stated above... it doesn't "like" being netted... like Zanclus, Dascyllus albisella, a bunch of other examples... it seems to die easily from "stress"...>
The tank is pretty much dedicated so it would not be much effort for me to meet any known special requirements.  Is there anything special I need to do?  Is my fish stocking plan destined to fail?
<Mmm, not necessarily... I think you have better chance than most all folks here... with your biotope of size, age... Just need to find someone willing to ship you the Damsels. I'd try contacting some of the "diver-direct" sources in Florida...>
If I need to change my fish stoking list, can you recommend another fish in the Gulf that would do well with my plan (perhaps the Purple   Reeffish)?
Thanks,
Chris Sanchez
New Orleans
<Mmm, well, there are always "standard" animals from here like the Pearly Jawfish... But do try the Chromis... Bob Fenner>

Re: Atlantic Blue Chromis (Chromis cyanea)   4/16/07
Bob Fenner, thanks for your reply.  Being that there are no other fish in my aquarium, would you still recommend quarantine?
<With this species, situation, no>
  My concern is that quarantine will cause additional stress that may lead to a higher likelihood of mortalities since QT tanks are seldom as large and as mature as the display tank.
<We are in agreement here>
  For example, I use a 3 gallon for coral quarantine with no skimmer or live rock and perform daily water changes.  A school of chromis would not do well here so I would need to start over on the QT setup.  What would you recommend as the minimum quarantine standards if I were to get the Chromis five at a time?
<I would still directly place this number, species, in the ninety posited, w/o quarantine... in batches>
Tank size, equipment, rock/substrate, aged (1 month, 3 months...)?  
Thanks Again.
Chris Sanchez
New Orleans
<Welcome. Bob Fenner>

How many chromis? Damsel Ident.... Dasc. re-send... 7/4/7
Hi Lisa, stocking question for you.
<<Hey Elise!!>>
My current set up is a 130 gallon FOWLER with a wet/dry trickling over bio-balls (supposed to be a nitrate factory, right? I am not experiencing this).
<<Not always. It may with time.  Water changes/macro algae can curb this.  Do keep on top of maintenance.>>
It has a built-in skimmer, which I have "tweaked" a bit to improve performance.
I have 75 pounds of live rock, turning nice and purple. The set-up is about a year old. Inhabitants are a four-inch blue tang (Dori, my pride and joy), a tank-raised perc clown, a juvenile sailfin tang, one yellow tailed damsel, two three-striped damsels, two other brown damsels of unknown species, a Banggai cardinal,
<<I prefer these are kept in groups.>>
a golden-scalped goby, two skunk shrimp, some hermit crabs, and two green chromis.  There is some minor bickering, but no one is getting picked on too much, so far.  (I know, I need to watch the damsels as they get older).
<<Do not underestimate how nasty some can get.>>
I have read that the chromis look really spectacular kept in a school.  I'm thinking about getting several more, and I'm wondering, how many could I get, assuming it's not a terrible idea?
<<Not at all.  I prefer them in groups of at least 7 if you have the room. I do worry about the number of damsels you have in your tank (clowns and chromis are dams too!).  If you can remove any of the damsels (not clown and chromis), I would.  Add a few more Banggais (tank bred only please) and 5 or more chromis.>>
I plan to not add any more inhabitants after this. I'm attaching a picture of the brown damsel, wondering if you can identify. (I apologize if it's too big, I don't know how to re-size and the computer genius is out of town!) I've been searching, but I can't find him.
<<hmm, I can’t seem to see it.  Do take a look here: http://www.wetwebmedia.com/damselidfaqs.htm, http://www.wetwebmedia.com/damsels.htm .>>
  Thanks, I'm still really enjoying the site, I peruse the FAQs every day.
<<Me too!  Glad to help my friend. Lisa Brown.>>
Elise

Stocking Opinion   3/31/07
Hi Crew,
<Jason>
Thank you for all your effort in providing this forum.  My tank is pretty much all stocked up, but I am considering whether or not to add another fish (tang) or small school of Chromis (four) to the tank.  I apologize if this is too much information,
<No such thing>
but here is what I've got:
This tank was up for 14 months before I tore it down and started again due to a massive green hair algae problem.  I think this was brought on by my lack of a chiller last summer and temperature spikes into the mid-eighties.  Current set up running for seven months and appears stable, but I remain paranoid about algae & bioload.
200+ gallon custom "show" configuration - 54" x 24" x 40" (tall),
<Wow! Hope you've got basketball player-length arms!>
maybe 240 g total volume w/ sump less rock.
2 x 250 MH lighting (10.5 hours/day/offset a bit) + 90W actinic (14 hours/day)
Several hundred pounds of live rock, & 4" live DSB
Sump filtration w/ sock, protein skimmer, activated carbon, UV sterilizer
Four water returns w/wave-maker and 3000 gph pump - nice variable flow.
Automatic water top off system and bi-weekly water changes between 10-25%
A chiller.  Water temp quite stable @ 79F.
Calcium reactor on order.
No refugium as there is simply nowhere to put it.
I can't figure out how to add macro-algae to the sump w/o fouling the pump.
<Screening, partitioning likely... to have water spill over... leave the algae behind... or divert main flow around the algal culture area...>
Water parameters checked weekly.  Calcium a bit high at 500ppm
<Yes...>
(Salifert), Alk ~ 11. pH 8.1-8.2, Nitrates/Nitrites = 0
I have numerous soft corals:
Two sizable toadstools
Large, growing leather coral
Purple frilly (I think) gorgonian- 18" tall
Five zoanthid colonies.
One frogspawn, one purple xenia
Two green polyp colonies.
Two other soft colonies I can't identify.
3 LPS colonies I can't identify
5 SPS (acropora) frags.  I started these about two months ago, and they are mounted at water depths less then 12", four of them within 6" of surface.  They seem to be growing well and I've constructed a coral skeleton high in the tank to mount some more if all goes well.  For now, I am waiting on Anthony Calfo's book on coral propagation before spending any more money.
<A good investment>
The fish:
1 yellow tang - 4" long
1 hippo tang - 2.5"
1 pair false percula clowns - 2"-3"
1 pair longnose hawkish - 3"
1 pair (male/female) watchman gobies- 3"-4"
1 six line wrasse (2")
1 unknown wrasse - 4" long (primarily purple body, wide yellow
horizontal stripe down each side, blue tail)
1 orchid Dottyback - 2"
1 pair cleaner shrimp
10 blue leg hermits
10 scarlet hermits
1 sally lightfoot crab. (The one with the yellow bands on its legs, not the one identified as sally lightfoot on WWM crab page.)
6 turbo snails, many Astrea 1 narcissus snail & two sand sifter stars.  (I think you disapprove of these but I got tired of cleaning the brown scum off my sand and these guys keep it pretty clean but not spotless, so they are hopefully not starving.)
<Likely fine here>
I have to admit, the fish are happy as is, so I am reticent to add.  The only problem is the male goby does not like the female, but I think there is enough room for them to avoid each other.
<Okay>
I feed 1 cube frozen mysis daily, sometimes 2 cubes.  Also feed a playing card worth of Nori most days, as in my experience the tangs starve without it and all the fish enjoy it except the Hawkfish.  (I should emphasize my experience with this.  I had ridiculous amounts of every kind of unwanted algae and my tangs still went skinny.  After I began feeding the Nori sheets in a clip, they remained healthier and pick more algae off the rocks.)
<Thank you for this>
I also use a light dose of plankton or DT oyster eggs most days with skimmer off for 3 hours, primarily for the corals. (Also a drop of Lugol a day in the sump, although not exactly "food").
So...hopefully that is all the info you could ever want to offer an informed opinion.
Would you recommend that I refrain from adding either an Atlantic Blue Tang (an Acanthurus in addition to my Paracanthurus and Zebrasoma) OR four green or blue Chromis to this party?  
<Mmm, all should go fine... I would make the Chromis number odd... 3 or 5 let's say... tend to stay in a school more...>
Separately, should I be concerned about too many corals as it relates to bio-load?
<Mmm, no... but do want to mention that if you were going to add more, you should do so... soon, and otherwise let what you have "grow up" by itself>
Thank you so much for this and all your other efforts.  For what its worth, I've bought two books by Anthony/Bob as a testament to the value of your knowledge.
Jason
<Well okay! Thanks for writing/sharing. Bob Fenner>
 

How many chromis?   3/31/07 Hello fish gurus,  I sent this a couple of days ago and haven't received a reply, <Mmm... haven't seen...> I attached a pic that I'm afraid was too big, so I have resized and I'm trying again. (sorry, hope I didn't crash your server). <If so, we'd tell you...> I have a stocking question for you.  My current set up is a 130 gallon FOWLR with a wet/dry trickling over bio-balls (supposed to be a nitrate factory, right? <Can be> I am not experiencing this, at least not yet).  It has a built-in skimmer, which I have "tweaked" a bit to improve performance. <Good> I have 75 pounds of live rock, turning nice and purple. The set-up is about a year old. Inhabitants are a four-inch blue tang (Dori, my pride and joy), a tank-raised perc clown, a juvenile sailfin tang, one yellow tailed damsel, two three-striped damsels, two other brown damsels of unknown species, a Banggai cardinal, a golden-scalped goby, two skunk shrimp, some hermit crabs, and two green chromis.  There is some minor bickering, but no one is getting picked on too much, so far.  (I know, I need to watch the damsels as they get older). I have read that the chromis look really spectacular kept in a school.  I'm thinking about getting several more, and I'm wondering, how many could I get, assuming it's not a terrible idea?  I plan to not add any more inhabitants after this.   <Mmm... I think it's a good idea to add more!> I am attaching a pic of the brown damsel, hoping you can identify it. <Mmm, the pic attached has a Dascyllus... but this is not a brown animal...?> I've searched, but I can't find it. It was an impulse buy.  I am afraid you are going to write back and say its species is "demon-from-the-netherworld" or something like that. They've grown a lot already, and they are aggressive little boogers, but the balance of power is intact, so far. <And in a system of this size, configuration, likely will continue... There are some very "bad" members of this genus: http://wetwebmedia.com/dascyllu.htm> Thanks again for all you do here.  I love reading the daily FAQ's, it's all so interesting. Elise <I would go forward with your plans for adding more Chromis... perhaps another five or seven individuals. Bob Fenner>

Re: How many chromis?   3/31/07 Ah, Mr. Fenner!  Shouldn't you be diving rather than answering emails? <Heeeee! Of course you're right....!> We will be in Hawaii in early June, our fourth trip to Kauai, and first to the Big Island. I can't wait to commune with my fish buddies (i.e. snorkel)!  Thank you again so much for your time and invaluable advice.  Here's a small pic of my system (Dori stopped to pose) Elise <Thank you Elise. Bob Fenner>

Stocking question... sort of like Seuss... One fish, two fish... wanting blue fish, Chromis   3/30/07
Hello WWM crew, love your site!
<Thank you>
I have been keeping freshwater fish for 35 years and switched over to saltwater 6 months ago and almost feel like a rookie again, as well as a child at Christmas.
<It is indeed exciting>
My current system is 110 gal with 110 lbs of live rock and 40 lbs of aragonite sand, 2 Seio 1500 ph, a/c 110 power filter with charcoal, which I change every 3 weeks, and a Remora Pro skimmer. I do a 12 gallon water change every 2 weeks with RO water. My current fish are 1 Kole tang, 1 Flame Angel, 2 False Clowns, 2 Firefish Gobies, a Royal Gramma, a Filamented Flasher Wrasse, 1 Tricolour Anthias
<Would do better with companions>
a Yellow Watchman Goby, 3 green Chromis', 3 blue leg hermit crabs, 2 Cleaner Shrimp, 2 Peppermint Shrimp, 9 various snails and about 7 soft corals. My water parameters are good although the nitrates stay between 10 and 15. My wife and I think we need some blue and were thinking of adding 2 blue reef chromis, my LFS says no problem but I am not sure. What would the experts recommend?
<Well I don’t think they would be a problem in terms of bio load. However they are shoaling fish and although they may join the 3 existing chromis they might look a little out of place, personally I think you’re stocking list sounds very nice at the moment. But technically you should be ok with these additions>
Thanks and keep up your much appreciated site.  Keith
<Thank you for your appreciation and good look with your endeavours, Olly>

Chromis Stocking advice. (Number; When) 2/18/07
Hi Crew,
<Hi Jason, GrahamT here.>
Thanks for your great advice in the past.
<Glad to be of service to the community!>
Now I have a request for simple stocking advice. I have a 90g reef tank (plus 30g sump/fuge) with ~120lb LR total. My current livestock includes:
  two black&white Ocellaris (max 2" long) <You mean now, not eventually, right?>
  one bicolor blenny (about 2.5" long)
  one purple Pseudochromis (about 1")
  one candy hogfish (Bodianus bimaculatus) ~4" [this guy can be a little aggressive towards the other fish]
<He *is* a full-grown adult, though usually a docile tank-mate. Goes to show you, personality can be a factor in any selection you make.>
I also have many soft coral, and a few large-polyped stony corals, and zoanthids/Palythoa.
<Sounds fun!>
I'd like to add a school of Chromis to the tank as my final set of fishes.
<May have been better to add before the Hogfish, and probably the Pseudochromis, as well.>
Given my setup, how many do you think it wise to add, if any?
<In that system-size/bioload, I would normally say 3, with no more than 5 individuals.>
Which species is best for schooling while minimizing size and care requirements?
<These are a favorite for both reasons. Also, Nemateleotris magnifica and Ptereleotris zebra are also notorious "groupers." >
Will my hogfish terrorize them incessantly (it continually chases the Blenny until the Blenny ducks into a hole).
<If he's spunky, he just might. Then again, he *shouldn't* perceive them as a threat, and they will likely defer to his/her superiority. Sometime when you look at blennies, they just seem to be saying, "So what?!? What are YOU gonna do about it?" and you can understand a hogfish's inability to cope... ;) If your corals aren't too established, and/or you can accomplish it without too much destruction, you can always re-decorate to throw off the territories.>
Thanks for advice!
Jason
<You're welcome, Jason
-GrahamT>

Re: Chromis stocking advice 3/28/07   4/2/07
Thanks for the advice, Graham!
<Welcome, thanks for writing in.>
In response to our last conversation... do you really think 5 is the upper bound on these?
<Well, within reason, you might add more, but they do grow large enough that their adult size would have them crowded at more than 5 or so.>
These are the last fishes I plan to buy for quite a while (if ever) for this tank, though more coral possible. My total volume with sump/fuge is ~120gal. I was initially thinking 9 chromis fish all introduced together. Overkill?
<It's your system. You might be able to make this work with the proper care and practices.>
Also, I never got the last response e-mailed to me (just saw it posted on FAQ). Guess it was a bug.
<Oh, yes. We have those.>
Thanks!
Jason
<Welcome again!
-GrahamT>

Mixing Chromis  1/29/07
Hello
<Hi.>
and thank you in advance to the Crew,
<You're welcome in advance....>
I have read through the FAQ's regarding the chromis and I can't seem to find the answer to my question.  Will Chromis cyanea (blue reef chromis) school with Chromis viridis (blue-green chromis)?
<Being very similar, they will at times "hang-out" in captive environments, I a little trouble calling what they do in captivity schooling, it's a very different behavior than that of the wild counterparts.>
I wouldn't mind if they did or didn't I just don't want world war III to break out in my tank.
<There could be bullying, damsels, even chromis tend to have a social hierarchy....really depends on individual specimens, no way to be 100% sure.>
My current three 1" b/g chromis  are schooling and doing well.  I like the look of the blues and would like to add two of them if they will mix, or three of them if they will school by themselves. The only other fish are a bottom dwelling goby and blenny.
<Well it is a risk, may/may not work....best to avoid if possible, but just for fun what is the size of the tank? Could/will make a difference.>
Paul
<**AJ.>

Blue green chromis beh., sel.  - 05/10/2006
Hello.
<Good evening>
I have a 25 gallon tank with 30 pounds of live-rock. It has been cycled for about a month now.
<OK good.>
About a week ago I added 2 Blue Green Chromis fish and 1 Black and Gold Chromis. The Black and Gold Chromis stays near the bottom guarding all of the live-rock,
<Somewhat normal>
snapping at the other two fish if they get anywhere near him. The two blue green Chromis fish stay near the top and
have gotten along so far, but today the larger of the two has been chasing the smaller one around the tank. Once the larger blue green Chromis chases the smaller one down to the bottom, the Black and Gold Chromis attacks the
smaller one. What should I do to calm them all down? Should I add another
Blue Green Chromis to make an odd number? Should I remove the Black and Gold
Chromis? Should I add a different larger fish to calm the Black and Gold
Chromis? I don’t want to overstock my new tank. Thank you!
<They are probably just showing dominance here.  Let them figure it out on their own - this normally works out once a hierarchy is formed.  No worries, but keep an eye on them anyway - make sure no physical damage is being done.  Have a good one, Jen S.>

Blue Reef Chromis in Nano..- 5/9/2006
Quick question - can I keep a single blue reef chromis?
<<I wouldn’t, no.>>
If not, can you suggest a good BLUE fish for a nano?  I have a pair of [very] juvenile (1") ocellaris clowns and a yellow watchman goby/candy pistol shrimp pair along with softies, zoas, mushrooms and various cleaning critters.
<<Look into neon gobies. Gobiosoma oceanops is one of my favorites, and has startling blue lines.  Read here: http://www.wetwebmedia.com/neongobies.htm.  They are great nano fish, although I’d worry about the other goby if your nano is very small..>>
Thanks!
P.s. Yes, within the next year they will all be going into a larger tank after I move.
<<Why not wait, then? Larger=more/different stocking options.  Lisa.>>

Chromis Query ... id, comp., sel.   4/8/06
Hi Y'all,
<Chris>
I'm just wondering if you could clarify any differences in suitability/temperament with Chromis or point me towards somewhere I can
find more info - I have checked the WWM pages and FAQs already (& other sources) but can't seem to find the answers I seek.
<... What little we have should be in the coverage, subFAQs coverage by the genus, family: http://wetwebmedia.com/marine/fishes/part2.htm
Scroll down to the Damsels, genus...>
My query is specifically around the differences between Blue-Green Chromis (C. viridis?), Blue Chromis (C. cyanea?) and the Green Chromis
(with black spot at base of pectoral fin?) (C. atripectoralis?)
<These are the most common species associated with these names... though there are often others>
I have seen recently Chromis labeled as blue Chromis which looked (in my humble opinion) nicer than the blue/greens, it is difficult to tell from
the picture on your Chromis page but the fishies that I saw had markings similar to blue devil damsels around the eye - small black splotch/band
- does this fit with how blue Chromis are generally marked?
<Mmm, if you mean mis-marked, labeled and/or appearing, yes>
The colour of these fishies was consistent with the deeper blue (as on your page) than the blue/greens.  How do I differentiate between blue/greens and
greens - is this the Pec fin black spot?
<Not definitive... unfortunately. Some batches, source locations have this spot, others no.>
Mainly my query is around the temperament of these fishies and any variances amongst variety - I am planning three of a single species for
my new tank (a month or two before I start stocking yet - still working on the lists!) They will be sharing the tank with 2 Black & white
Clowns, a couple of Banggai Cardinals & either a Flame Angel or a Coral Beauty (being tempted by the Coral B here) along with mainly SPS coral.
On the basis of aesthetic value I am leaning towards the Blue Chromis (assuming you confirm that the fishies I saw labeled as such with the
eye markings are indeed likely to be Blue Chromis) however behaviour and temperament (particularly as these are damsels!) are more important to
me as I want all of my charges to co-exist as harmoniously as possible! On this basis is there much to choose between the blue, green/blue and green?
<Viridis are the easiest going, most likely to mix with its own species, others... Cyanea next, Atripectoralis last... though all three of these Chromis are far to the left in terms of the spectrum of Pomacentrid aggressiveness. The short answer here is I'd go with the Blue-greens if this were a concern. Bob Fenner>
Many thanks as ever
  Chris