My tank is dying

[Adamski]

I woke up this morning to feed my tank and none of the fish were visible in the water column. Only my blue lights were on so I waited for the whites to come on and still nothing. Finally my tang emerged and was feeding as normal. I found my clown fish on the sand bed, hidden and he's gasping and looking very ill :-( no signs of any spots of marks on him. I have since found the chromis dead. I have moved around as much rock work as possible and can't locate any other fish. I have 6 fish missing. All my corals look the same.

Temp: 78.3
SG 1.025
Calcium 430
Alk 7.7
Mag 1300
Ammonia 0
PH 7.8
Unable to test nitrate/nitrite
System is about 15 months old. Only home made RO water used

Any help would be appreciated. Totally gutted


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[Beej1254]

Have you recently done anything to the tank? Any chance outside contaminates somehow could have made it in like sprays or something on your skin?


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[coralbandit]

Since test look good install carbon in the system in case as mentioned a contaminant .
Is your pH always under 8?
Do you have a lid?

 

[Adamski]

I've got a mesh screen as I lost a goby due to jumping. I have carbon running and I'll replace it when I get back. I am so anal about maintenance that I still keep a diary of everything and there's nothing that I've done different for over 12 months. I even do my water changes at the same time every week. I changed my filter sock for a brand new one last night, can you get contaminated filter socks? It was brand new in a packet


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[Adamski]

Sorry yes my PH has been the same for 14 months. I'd like it higher but went for stability rather than chasing the numbers (does that make sense?)


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[Beej1254]

I doubt it was something in the filter sock. How big is your tank? How much do you do in water changes? Stability is very important your right but that also means monitoring nitrites and nitrates.

I would look there next because if your bio load is heavy for the tank and you don't know what your nitrates are at then even doing regular water changes may not be doing enough. It's just my guess. I tend to watch my tank consistently throughout the day and even though everything looks great and the fish are happy I've definitely surprised myself with how high my nitrates have been. Even when on regular maintenance schedules.


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[Adamski]

I couldn't test as I had to go to work so will test when I get home. My nitrates have never been over 2 and I test everything twice a week. My tank is 300 litres and defo not overstocked


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[Adamski]

I do 10% every week and have done every single week for over a year


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[Beej1254]

I'm kind of stumped at the moment. I don't doubt that you do what you do just trying to help whittle down some options. Have you found anything yet? If everything has been how you say then I keep coming back to some kind of contamination. Or maybe spoiled frozen food? I don't know what you feed but just a thought. Something that effected all of your fish so drastically had to be sudden but hidden. What kind of screen kit did you use? I've never done one but does it use some kind of glue? Or anything? I hope you find an answer soon.


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[Adamski]

Thanks I really appreciate your help. I use the mesh screen top but it isn't glued down. PE mysis and frozen krill is all I've fed. The only thing that I did differently was use that new filter sock. I'm tempted to soak the other new one in RO water for 12 hours and test that water


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