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[pneuma]

Hi I am new to the forum and relatively new to fishkeeping. I have a 128l Boyu tank. Since Friday of this week, I have lost four fish - yellow tang, koran angel, coral beauty and another type of angel in very quick succession. I have checked my levels and my nitrate was the only one that was too high. I have been told by local fish shop that this in itself will not kill the fish. I have perfomed two water changes, one yesterday and a partial change this morning. The latest death was the koran angel which seemed to be fine yesterday and fed last night even though he had been listless before first water change. My corals also seem fine, mushrooms out as normal, leathers ok. I also have a sea urchin which seems fine.

None of the fish showed any signs of disease and have all been happy in he tank up to Wed/Thursday.

Nothing in the tank has changed. One problem last Sunday was the water circulator which had been off for at least 7 hours and which had lowered the temp of the water for some reason. I bought a new temp guage thinking that was the problem but discovered later in day that it was actually the water circulator. This is the only event that I can think of that has upset the tank however, the problems did not kick in until Wed/Thursday.

I am at a loss as to what to do next.

Appreciate any guidance.

 

[Fishmonger70]

Why don't you start off by telling us a little more about your setup, i.e. what type of filtration you are using such as live rock, protein skimmer, what kind/how much or water movement, what the levels of all of your water parameters you measured are like Ph, ammonia, nitrite, nitrate, KH, temp, SG, etc.

 

[pneuma]

Hi

All the water parameters tested on both Saturday and Sunday. Saturday's test indicated that nitrate level was high. Carried out a water change and that brough that parameter down to an acceptable limit. On Saturday this was the only one out of kilter. On sunday retested the water, and ph was low 7.7. Our local fish shop recommended that we introduce some gravel which hardened the water and counter acted the ph. Not sure what it was called.

The tank is a Boyu tank with its own protein skimmer which is regularly changed. Water changes happen every 2nd saturday though because of this problem, have done water changes on two consecutive days (sat/sun). Have live rock and have 7 corals, including leathers, mushrooms, green xenia and cladiella. All the corals and the live rock seem ok.

Since the second water change, things appear to have stablised but I am not sure what would have caused such a major loss in such a short space of time.

Hope this helps.

 

[Lotus]

I think your main problem is that it's a small tank--128 liters/38 gallons--with large fish. As soon as the pump/powerhead went off, the oxygen in the tank got too low, killing the fish.

 

[Fishmonger70]

That would do it. I didn't notice the size of the tank was in liters in your first post. You are way overstalked, and you don't want to have a yellow tang in tank that size or he will be your next victim.

 

[pneuma]

HI

Thanks for your comments. Tank now down to five fish, two clowns, two blue damsels and a regal tank. PH is sitting between 7.8 - 8.0.

Hopefully things will begin to settle down. Looking forward to learning something more about the fish.

 

[quaddity]

Wow you had all those large fish in a 38 gallon? You are at almost your max stocking limit with just the two damsels and clowns. No large angels or tangs in a tank that small. I would agree with the above. Massively overstocked with no water circulation = no oxygen.

 

[susieq728]

Personal suggestion, get rid of the damsels. Give them to your local shop. They can be beautiful but too aggressive for most other tank mates. And from my experience of introducing a yellow tang into a 55 gal., it jumped out. I'm not getting anymore tangs until I have more room for them. He seemed happy and fine until I came home one day and was gone.

 

[Fishmonger70]

Pneuma, I would sell off the Regal Tang too. He will not do well in a tank that is less than at least 75 gallons and would be even better at 120 gallons. He will most likely parish from stress related to lack of swimming space.