Sudden loss of fish...HELP!

[Matt2112]

All of my fish died early this morning (or late last night). I found my purple tang, three blennies, and my eibli angel dead at about 7am. The bizarre thing is that ALL of my corals, hermits, and cleaner shrimp look GREAT.

I have a 125 gal reef with a 4 inch deep sand bed, 200 lbs (+/-) of live rock, use RO/DI, instant ocean, drip kalk with a doser, metal halide/VHO combo for lighting, 4 powerheads on a wavemaster pro and a red sea protein skimmer. All parameters seem to be in line – nitrates 0 to 5, calcium about 450, iodine .04, KH 7.7, pH 8.4 +/-, no nitrites, no ammonia, and no phosphates. All of my test kits are Salifert except for the phosphate. My temp ranges from 80 to 84 (and has been like that for years).

This particular tank has been set up for 7+ years. I added the live sand over 3 years ago. When I noticed the dead fish, I checked the sump and the protein skimmer was full and foaming up over the top. It was a clump of white foam about the size of a football. It had no odor. My skimmer usually produces a real dark liquid and it would take months to even fill half of the container (I don’t have a huge fish load by any means). Nothing was added, changed, moved, or disturbed. I fed the fish at about 9pm Friday night and all was well as usual.

I have been keeping saltwater fish successfully for over 15 years and various reefs for almost 10 years now. Sure I’ve had fish die – but not all of them at once. I have no idea what could kill ALL of the fish and not affect any of the corals, shrimp, etc. After speaking to a friend, the only possibility I can think of is that my cucumber (red/pinkish) may have expelled some sort of toxin. But wouldn’t that affect the corals to some degree??? The corals look better than ever!! I havent' even seen the cucumber since it was added 2 years ago...

So I did a 25-gallon water change using RO/DI with instant ocean a few hours ago. The foaming has slowed in the skimmer but hasn’t stopped. Any help, ideas, or suggestions would be helpful. If I get a chance, I’ll post pictures of the tank to show how good everything else looks – but I’m more concerned as what to do for now. Please help!!! Thanks!

PS - Sorry for the long post...I just wanted to give as much info as I could. Also, I'm making some more RO/DI and plan another 25 gallon change ASAP. Thanks again!

[ September 02, 2001: Message edited by: Matt2112 ]

 

[Anonymous]

Your friend may have you in th right direction. Your inverts may not have the type of central nervous system that would react to that type of toxin.

With what has happened and seeing as how you have done your tests, I would be doing water changes till the cows come home. I would not add anything untill i was comfortable with the amount of water changes.

No sea apples or nukes, I mean cukes for this reef keeper.

 

[Matt2112]

Fishaholic - Maybe the cucumber was it...but what would make it do that? It's been in there for quite some time with no problems. I almost hope that it's the reason for my loss - just so I know what the hell happened. But the problem is getting the damned thing out. Like I said in the original post, I haven't even seen it in 2 years. Believe me, if I can get it out, it's going back to the LFS regardless. I'm just not sure if that was it though...Thanks for your quick reply!

 

[Anonymous]

Anythig that has the ability to break the ckes layer of "skin" would get a defensive response, the release of toxins. Usually a crab can set one of or being nipped. For the fish to all die that quickly without any trauma and no signs of strees it points very hard to toxin or poison. Most poisons would wipe out your shrimp too.
Sometimes you must go with your best hunch, I would be finding a way to make a list of possabilities but from your description, That cuke is looking preaty guilty.

Also if you cannot find him he may have died and when preyed upon here comes the release of toxins.

[ September 02, 2001: Message edited by: Fishaholic ]

 

[davelin315]

I don't think it's the cucumber, although it very well could be. As fishaholic points out, your shrimp would have succumbed as well. IMO, the shrimp would have been the first to go, and then your fish. A possibility, which IMO is more likely, is that maybe your fish were electrocuted (?). I don't think that corals and shrimp are affected by currents in the water as much as fish are, so maybe that was it. Can't say for sure, though, so anyone elses guess is as good as mine, or maybe better. One thing, though, how did the fish look when they died? Were their gills flared out as if they had opened their mouths as wide as possible gasping for oxygenated water? If so, that would point towards poisoning of some sort or oxygen depletion (I think). If they looked normal, mouth not opened, gills flat to their sides more or less like a normally functioning fish, then I would think it is more likely electrocution, or something else very sudden.

Keep in mind, these are all guesses, but I think how your fish appeared in death is a good indicator and will point you in the direction of the culprit. Again, I think if the cucumber were the culprit, your shrimp would be dead.

 

[cstar]

I'd second Dave Lin's opinion on lack of oxygen. Due to the fact it happened overnight, it could also be a large drop in Ph.

Sorry to hear of your loss.

 

[Matt2112]

Thanks for all of the replies...

Dave Lin - Eventhough I want to believe it was the cucumber, I'm not too sure either. It seems to me that the shrimp would have died and the corals would have been affected somewhat from toxins.

The fish looked fine when I took them out - no signs of stress, flared gills, spots, or anything. As far as oxygen depletion, I have plenty enough water turnover and don't think that's it. But the electrocution theory may have some merit...however, I do have a grounding probe and everything is hooked up to a GFIC. A few days ago one of the powerheads started sounding like a blender when the wavemaker kicked it on. I’m wondering if it may have burned out or something. I’m going to see if all of them are working right now. It may be hard to tell because they are buried in the LR….

cstar - My pH was 8.4 at about 7:30am (I tested after I pulled out the fish). Would my pH be able to drop enough to kill all of the fish and return to an acceptable level that quickly? I've never really had any huge pH swings in the past...

I appreciate all of the responses…any other theories as to what may have caused the sudden deaths???? I don’t want this to ever happen again.

 

[cstar]

Matt,
Ph the problem? Possible yes, probable, I don't know. I speak from bad experiences in my tank.

The best thing I can recommend if you think Ph may be suspect, is to test just as your lights are going out and then again in the middle of the night or dark period and then again before lights on and mid-day. This will give you a more complete picture of what is happening in your Ph cycle.

8.4 seems high to me for 7:30 am (in a tank like mine, that is the lowst point in the day), but that depends when you are running lights, dripping kalk or if you have a reverse photoperiod sump. From what you said I would guess that maybe it's not necessarily a large drop but your high point is too high, possibly high enough to kill your fish.

Good luck, and certianly investigate other possibilities.

 

[Matt2112]

cstar - I drip kalk with a timer and my pH is pretty stable. I really don't think that was it. Electrocution seems more likely. I just need to figure out how and what did it. Thanks for the info!!!
Matt