Fish swimming erratically then dying.

[dan9960]

I've had my 120 gallon reef tank going for about 2 years now. I've had 12 fish in it for over a year, 4 blue/green chromis, 2 purple firefish, 1 pintail wrasse, 4 Chalk bass and a Powder Brown Tang. Starting Sept. 30th, one of the purple firefish started swimming around really fast and crazy. Loopty loops, bouncing off rocks and walls. Two days later, it was dead. One by one all the other fish, have done this behavior and died.
I haven't changed or introduced anything to the tank. The corals, mostly zoas look good. I have snails for my CUC and they don't seem to be affected. Until this started happening, everything was going good. I don't see any outward signs of parasites or anything for that matter. My parameters are all in range. I tested for ammonia and nitrite and both are zero. At this point I'm down to 2 chromis, 1 chalk bass and the pintail wrasse.
Any ideas what could be causing this?

 

[vetteguy53081]

I've had my 120 gallon reef tank going for about 2 years now. I've had 12 fish in it for over a year, 4 blue/green chromis, 2 purple firefish, 1 pintail wrasse, 4 Chalk bass and a Powder Brown Tang. Starting Sept. 30th, one of the purple firefish started swimming around really fast and crazy. Loopty loops, bouncing off rocks and walls. Two days later, it was dead. One by one all the other fish, have done this behavior and died.
I haven't changed or introduced anything to the tank. The corals, mostly zoas look good. I have snails for my CUC and they don't seem to be affected. Until this started happening, everything was going good. I don't see any outward signs of parasites or anything for that matter. My parameters are all in range. I tested for ammonia and nitrite and both are zero. At this point I'm down to 2 chromis, 1 chalk bass and the pintail wrasse.
Any ideas what could be causing this?

With coral and inverts doing well, it diminishes the chance of water chemistry being an issue but rather disease. can be stray voltage cause the erratic behavior as would flukes and other irritants such as ich or Amyloodinium
A video would have been of great help when these behaviors were occurring

 

[DaJMasta]

How's your flow? Any dead spots near the bottom? Any time of day when the pumps are off for an extended period?

Fish can behave erratically when short of oxygen, and especially if at night, may not be all that noticeable for the coral. Ammonia spikes can also do it, but I would expect it to harm at least some corals, though it may show similar symptoms in more livestock during the event (panting, unusual behavior, trouble staying normally oriented, etc.)

 

[Jay Hemdal]

I've had my 120 gallon reef tank going for about 2 years now. I've had 12 fish in it for over a year, 4 blue/green chromis, 2 purple firefish, 1 pintail wrasse, 4 Chalk bass and a Powder Brown Tang. Starting Sept. 30th, one of the purple firefish started swimming around really fast and crazy. Loopty loops, bouncing off rocks and walls. Two days later, it was dead. One by one all the other fish, have done this behavior and died.
I haven't changed or introduced anything to the tank. The corals, mostly zoas look good. I have snails for my CUC and they don't seem to be affected. Until this started happening, everything was going good. I don't see any outward signs of parasites or anything for that matter. My parameters are all in range. I tested for ammonia and nitrite and both are zero. At this point I'm down to 2 chromis, 1 chalk bass and the pintail wrasse.
Any ideas what could be causing this?

Can you post a clear video of the remaining fish under white light? Hosting to YouTube works well if you are not able to upload a video directly here. It does sound like a fish disease since the inverts are all doing o.k.

It *could* be low oxygen, but if so, something must have changed for the fish to begin having issues after a year.


Jay

 

[dan9960]

I checked for stray voltage, with and without the grounding probe. No stray voltage. For flow I have 4 MP40s. When I feed, I see how it's dispersed and there don't seem to be any dead spots.
The remaining 4 fish seem to be doing a lot of hiding in the rocks. Still no outward signs of anything. It's almost impossible to video them when they start flipping out. It's sporadic and only lasts for 3-4 seconds. Once the fish does that though, the clock is ticking.
If it's due to low oxygen, how do you test for that?

 

[Hawaiian AQ]

Seems low o2 would be unlikely if your corals/inverts are doing well like Vetteguy said. Your ph would be really low if you had low o2 and your corals would close up. Usually just mixing your water with an open top tank will provide a livable amount of air

Seems like disease or poisoning of some sort. Hard to say without a video

 

[Jay Hemdal]

I checked for stray voltage, with and without the grounding probe. No stray voltage. For flow I have 4 MP40s. When I feed, I see how it's dispersed and there don't seem to be any dead spots.
The remaining 4 fish seem to be doing a lot of hiding in the rocks. Still no outward signs of anything. It's almost impossible to video them when they start flipping out. It's sporadic and only lasts for 3-4 seconds. Once the fish does that though, the clock is ticking.
If it's due to low oxygen, how do you test for that?

Oxygen itself is difficult and expensive to test for. You can sort of get an idea as to overall gas exchange by measuring the pH before the lights come on in the morning and then at the end of the day just before they go off. If there is a wide variation, low in the first reading and high in the second, there is CO2 problem that goes hand in hand with low oxygen. I prefer a spread of less than 0.5 pH units.

 

[DaJMasta]

There are actually chemical DO tests - salifert makes ones and they aren't the only company. Otherwise you need a dissolved oxygen meter, and while common in water measurement applications, they do not come cheaply.

 

[Jay Hemdal]

There are actually chemical DO tests - salifert makes ones and they aren't the only company. Otherwise you need a dissolved oxygen meter, and while common in water measurement applications, they do not come cheaply.

Those tests as well as regular membrane meters are difficult to get good readings with. An optical sensor DO meter works well ($1600?) as did the old Chemtrics photometric ampule test.

 

[DaJMasta]

I got reasonably good consistency with some informal tests between the Salifert ones and a YSI multiparameter meter (on the used market they can be a few hundred, but it's likely that the membrane/electrolyte will need replacement and you have to sort of best estimate calibration.)

With DO testing I've found it's more the inconsistency between time and location - in a tank with a time in low DO, it's likely it will change by 2-3 mg/L over the course of the day, so you can measure during the day with the flow going and it will look largely fine whereas when flow is lower and without photosynthesis it drops pretty significantly. I ask about time with pumps off in particular because that's when the stratification really happens and it gets rougher for fish sleeping in/under things in particular. I know in my tank with its current load I start to see low oxygen symptoms (panting, unusual behavior) after about 1.5 hours of the pumps being off, and that the first fish to be effected are the ones near the sand bed and not moving around much.

Those adhesive patches used in optical DO sensing are definitely the top choice if you're looking for long term monitoring, but even after you buy the measurement equipment and software, the patches themselves are like $50+ each

 

[dan9960]

I checked my pH in the morning and then again when the lights went off. There is indeed a big swing. It was 8.00 morning, 8.17 before the lights went off. When I do my testing, my pH has always been around 8.20. I test during the day. So it looks like there is a CO2/low oxygen problem.
I've got 4 MP40's for flow. They are on 24/7 programmed with different flows. I did make adjustments to them on Sept. 2nd, lowering the flow slightly. They are on 24/7 programmed with different flows. Other than increasing flow, what else can I look at or try to correct this CO2 issue?

 

[ReefED!]

8 in the morning to 8.17 is not a big swing, and that's not going to result in fish dying

I would look more towards flukes or ich/velvet in the gills. Especially with the reclusive fish.

Chasing CO2 here is a red herring.

 

[JohnNYC8]

I checked my pH in the morning and then again when the lights went off. There is indeed a big swing. It was 8.00 morning, 8.17 before the lights went off. When I do my testing, my pH has always been around 8.20. I test during the day. So it looks like there is a CO2/low oxygen problem.
I've got 4 MP40's for flow. They are on 24/7 programmed with different flows. I did make adjustments to them on Sept. 2nd, lowering the flow slightly. They are on 24/7 programmed with different flows. Other than increasing flow, what else can I look at or try to correct this CO2 issue?

Not a big swing and PH in that range is great.

 

[slingfox]

I checked my pH in the morning and then again when the lights went off. There is indeed a big swing. It was 8.00 morning, 8.17 before the lights went off. When I do my testing, my pH has always been around 8.20. I test during the day. So it looks like there is a CO2/low oxygen problem.
I've got 4 MP40's for flow. They are on 24/7 programmed with different flows. I did make adjustments to them on Sept. 2nd, lowering the flow slightly. They are on 24/7 programmed with different flows. Other than increasing flow, what else can I look at or try to correct this CO2 issue?

Do you run a tote in skimmer? That is a good way to ensure oxygen is not an issue. That said, I doubt this is what killed the fish if you have 4 MP40s.

Have you considered getting an ICP test just to make sure no contaminants. This is also likely a no -issue do you inverts and coral are doing well.

With the low fish load, why not remove the 4 remaining fish and putting them through medicated quarantine and letting the display run fallow? Then add in only quarantined fish to reduce risk of disease which sounds like the most likely explanation here.

 

[Hawaiian AQ]

Are you running a standard reef system? Recirculating, sump, skimmer the works?

If so, it probably isnt o2. If for some reason you’re still worried about it, just aerate the tank more. You can’t over do it. IMO, this is the least likely possibility

Temp is good? Has anyone used any aerosols, painting, cleaning agents etc near the tank? Stuck your arm in after having something toxic on your skin?And how about disease. The fish that died, did you examine them closely for parasites/disease?

You see any cloudy eyes, rubbing, color change etc?

 

[DaJMasta]

pH is not the same as DO. Yes, pH drops when more CO2 is in the atmosphere around the tank, but the concentration of CO2 doesn't just automatically replace the concentration of O2 dissolved in the water. I don't think there's even much of a correlation between DO and pH aside from that the generation of O2 in photosynthesis consumes the CO2 in the tank which raises the pH.

With 4 MP40s at a reasonable setting, I doubt you would have issues either, but that's why I specifically asked about time when the pumps are low or off. If you don't run a reduced schedule at night in terms of intensity or haven't had any lengthy periods where multiple pumps were off, the only real possibility for DO issues would be isolated pockets of almost no flow that have a bunch of life in them (crevices in some rocks, for example), and that is unlikely to be effecting free swimming fish - a firefish living in a hole under the rocks, however, could absolutely run into this issue.

Provided your stocking isn't super high (and it's not for that volume) and your ambient air has a normal amount of O2 (it probably does), it is unlikely that DO is an issue unless water stops moving for a length of time.

Aerosols are a good potential thing to check - even incense and cleaners used in another room can be a problem. Could be worth testing your RO for TDS and maybe your tank for an ICP to see if the less common parameters are getting out of whack, but often those will have issues with corals too. Also check to make sure nothing could be dripping or falling into the tank without you noticing.

 

[dan9960]

That's good to hear about the pH. Here's pics of the chromis that I found today. Tried to get good shots of the gills, I don't see anything like parasites. I got my ICP test back today and my iodine is a little low, but that's it. I've never dosed iodine.
I've been trying to think what changed around the aquarium when this started and I can't think of anything different. No cleaners, incenses nothing. I don't have a quarantine tank setup and at this rate, I don't think the remaining three fish are going to last long enough to transfer them. I just wish I could figure out what this is, so I can correct it. I don't want to go fallow, put fish back in and have this happen again.

 

[ReefED!]

You're not going to see parasites with the naked eye

You need to do skin scrapings and gill scrapings - you can learn about that on Humblefish and use a cheap microscope to do it.