Disappearing Chromis - HELP!

[Shooter7]

I've had this 10 gal mini-reef tank for about 3 1/2 months now, bought it already established from another local reefer. Has 15 to 20 lbs LR, several coral frags (zoa's, frogspawn, xenia, ricordia, shrooms), snails and fairly small blue-legged hermits. I have been monitoring this tank all that time with no fish in it wanting to make sure I had stable water parameters before I tried introducing any fish. Tested last weekend, temp 80, pH 8.3 or .4, ammonia 0, trites 0, trates 0-1 maybe. Happened to be at Petco and they had some itty bitty chromis there that I thought would go great in this small tank and could eventually be moved to the larger tank I'm setting up. And on top of that my wife loves them. So I pick up three of them. They seemed to be really happy in this tank, playing in the current from the powerhead, munching the very numerous pods in the tank. First full day was fine, after the second night - one fish missing. No trace. Third night ok. Last night, fourth night, next morning - one more fish missing. This time spotted the skeletal remains of one fish on the substrate, totally picked clean. There are very numerous bristleworms in this tank, a couple of them quite large (5 - 6 inches long), but many many smaller ones. Any idea what I might be dealing with here? The fish look really healthy and ate well, looked fine while the lights were on. No previous evidence of any predator in the tank. My only thoughts would be sick fish (but they sure don't look sick) or something nabbing them at night (hermits or bristleworms - although I keep reading bristleworms are not predatory).

Thanks for any input.

[MartinH]

Probably not bristleworms, but if the fish are small enough, crabs could grab them. Also, have you done a water test since you added the fish? Since one (at least) has died, you definately should do a water change in my opinion, there will be ammonia present now. A tank that small can have wide swings in water quality in a short while, that is why they can be challenging.

Also, as a side note, you will want to get the nitrates down or your corals may suffer.

Good luck!

[Shooter7]

hmmmm...."get the nitrates down"? Can't get much lower than zero. I posted them as being zero to one maybe. Just tested the ammonia again, even though from my freshwater experience with small tanks I didn't expect these little fish to produce that much ammonia, plus the tank has been established for some time, but they are, indeed, zero still. Nitrates are still testing at zero or maybe just slightly above (and all of my little coral frags look very happy).

I just can't figure how one of these little hermits could have nabbed one of these zippy B/G chromis. The chromis are about an inch long, if that. The hermits are all smaller. It just boggles me.

[hpmcbroom]

Fish sleep some near the bottom or by rocks and that's when they are caught by the hermits or other scavengers. Unaware and easy targets.

[Shooter7]

Suggestions then?

No fish in this tank until I can switch the hermits to my larger tank?

Rig up a bristleworm trap and try to dispose of the larger ones?

Both?

[hpmcbroom]

Worms can be good for the tank so no providing they're not bad . I would switch out the hermits though . Get some nassarius to stir the sandbed . Then try a fish again. Hermits are cool but I don't trust 'em . I lost a damsel myself once to a hermit crab in the early years.

[Fenix]

Chromis are not a schooling fish unless it is a big tank and they feel theretend. They probly were trying to establish dominace over each other and killed each other. Three chromis in a 10g is way to many. One is all a 10g can handle.

Go ahead and setup a bristleworm trap. The bigger the worms get the braver they are and they will start to take nips out of your fishes fins and stress them to death.

[DaddyJax]

I agree with only one chromis but curious, any clicking noises?

[tanker]

Originally posted by Shooter7
Suggestions then?

No fish in this tank until I can switch the hermits to my larger tank?

Rig up a bristleworm trap and try to dispose of the larger ones?

Both?
DO not think that either a brit-worm or crab can catch a chromis. They are not as hardy as people think. They also aggressive (semi). Maybe you got poor stock??

[Shooter7]

Well, I lost the last of these three little fish last night. At least got the chance to see that this one was acting a bit sickly before lights out. Somewhat pale, breathing heavily, having some trouble keeping his equilibrium. I re-tested the water for the tests I have available, pH 8.3, ammonia 0, trites 0, trates 0, and I looked at the salinity level again. Now, I just recently (about a week ago) looked at the salinity and it was 1.024. I had not been concerned about salinity because I had only added RO/DI water as topoff since the last check and my salinity had been stable for the last couple of weeks (since I got my RO/DI unit and had that water available for topoffs). However, salinity last night was 1.028.

So, first off, would this elevation in salinity be enough to cause my little chromis to get ill? Secondly, any ideas on why my salinity would have crept up on me like that? The water was not low at the time of testing (I changed out some water last night to start bringing the salinity down slowly). And finally, any ideas on other water parameters that could have killed these fish? I know that this tank, after the lights have been on for 7 or 8 hours, starts getting alot of bubbles forming and rising up in it, like from the sandbed. I even noted some bubbles on the sides of this fish before it died. Is this indicative of some weird gas exchange issues going on in there? Not sure just how much all the corals, inverts, and previously mentioned bristleworms I have in this small tank might affect things like that. Otherwise, I'm a bit baffled. :confused: Thanks for any input.

[DaddyJax]

What are you using for top off water? Is it premixed or unsalted?

[Shooter7]

Plain old RO/DI water....salinity of it = zero


Love that picture, btw. :D

[DaddyJax]

Thanks thats my Ex-girlfriend! :D J/K
Well the only thing I can say is check you tester for bubbles cause mine will give false readings if it has any on it! If thats not the case than let me know cause I'm curious! Btw Any clicking sounds at night?

[Shooter7]

nah...no indications of predator issues at this point. I think the fish just got sick or whatever the deal is and then the scavengers took over. This tank was established for a pretty fair amount of time prior to me buying it from another person and then setting it back up again, so I don't think there is any hidden mantis or anything. Although...did see a very curious looking pale red worm with very long white hairs sticking out of it for the first time the other day. Definitely not a bristleworm, but only maybe an inch or 2 long.

[tibbs2]

Bristleworms don't eat fish. I'd remove the crabs or look at another possible cause.

[Shooter7]

LOL...better tell that to the big ol' bristleworm that was chowing down on the last of my little fish when I found it late last night.

Now, do you mean they don't "attack" and eat healthy fish, or that they don't eat fish at all? 'Cause I know the latter one is not correct. These fish would die at night and by the time I wake up in the morning, the bristleworms have completely skeletonized them.

And pursuing other possibilities is exactly what I'm doing. :)

[Shooter7]

A "still looking for input" BUMP :)

[MartinH]

My only other input would be that I read a thread recently where fish were dying overnight, and it ended up that the cause was most likely low oxygenation due to low flow. So macro and other algae use oxygen in the dark,etc. I don't know if that helps, it's just a thought. Hope you find out what the problem is!

[Shooter7]

Well....don't think flow is a prob. It's actually rather "breezy" in there. I have a HOB filter that is probably a size bigger than would normally be on a 10 gal tank, along with a good powerhead going too. Judging by my little floating thermometer that moves around the tank from time to time, there really aren't any dead areas in this tank.

Talked to some very experienced local reefers and they seemed to be in agreement that they think it was a matter of bad stock. I keep thinking it must be something I did, but I just can't come up with anything. And my snails and hermits and such all survive in there just great. I had a yellow-tail damsel in there about a month and a half ago for about 2 weeks and he had no troubles at all. I just got rid of him because he kept fanning the substrate in drifts over some of my corals and he just had to go back. LOL Point of that matter is, though, that he had no health probs at all in the same tank, same parameters. Still, kind of afraid to put another fish in there. Maybe I'll try a more reputable store and then watch the fish more closely once it's in there. Thanks for the replies.

[tanker]

Originally posted by Shooter7
A "still looking for input" BUMP :)

As stated before, chromis are not really that hardy. You also could have got bad stock. You say you have good flow==
5 to 10X capacity is about good, also good surface movement helps add oxygen to water.

1.028 is high but not a killer. FOWLR 1.022- 1.025 is OK
Reef 1.025-1.028

[CletusKlump]

I would tend to agree with the hardiness of the fish.