Need Help - New Tank - Fish Dying

[IanD]

hello, I have fishless cycled my tank for two months (had an issue where I overdosed my ammonia and had to wait awhile for nitrites to come down).

My levels before adding fish were: 0 ammonia, 0 nitrite, 0 nitrate, 1.025 SG, 78.5 F water, pH 8.4.

Tank: 69 gallon AIO. No refugium yet or powerheads. Circulation pumps are pretty strong and protein skimmer is on. I have a section of live rock with dry rock for rest of aquascape and a sand bed.

Sunday my LFS tested my water and I then added 2 small ocellaris, a small tiger pistol shrimp, and a small wheelers goby.

I drip acclimated the fish for 30-45 minutes and temp matched tank. All seemed well 6 hours in and then I went to bed. They all ate before bed (frozen mysis). Upon awakening, pistol and both clowns were dead.

Levels were exactly the same. Wheeler goby is still active and eating.

What happened? I don't know why goby would still be alive while all others died. I'm afraid to add more fish because something must be wrong..

This is my first tank and I'm really depressed about this.

 

[T-J]

Based on what you posted, it's hard to see an obvious issue. So, some things to look for might be stray voltage, check the fish store water and see how different it is from yours, and verify that the animals you brought home weren't already stressed/diseased/dying.
Those are the only things I can think of off the top of my head. Again, I don't see anything in your numbers that should affect fish like that (your salinity is low for my liking, but I don't see that as a fish killer).

 

[Uncle99]

In an 8 week old tank, I can’t see how you could get nitrate to zero, it should have been very high as the extra ammonia you added would become nitrite, then nitrate.
Something seems wrong in the parameters Ammonia 0, Nitrite 0, Nitrate 0, all three “can” kill just at various levels.
Can you confirm those numbers.

If this tank has no corals, I would drop that salinity to 1.022-1.023, lower salinity puts less respiratory stress on the fish.

 

[IanD]

The LFS recommended that I used ALGONE to reduce my nitrates (they were sky high after nitrites went down), which is why they are 0 now...

Was that a mistake? For salt I'm using Instant Ocean. I also have no corals yet, so I should lower the salinity of my added salt water during my next PWC?

 

[Uncle99]

You don’t need to run salinity so high while you have fish only, you can, but no real benefit.
1.022-1.023 is fine. You can easily add RODI to bring it down, then just mix the new batch at the new level.

I really don’t know what to say about Algone. Normally, after nitrite hits zero, I would have just done WC to bring nitrate downwards.

How are you getting you PH to 8.4, again great for corals but difficult to maintain.

 

[DeniseAndy]

You never actually want your nitrates at zero. Unfortunately, I think you got some less than ideal advise. When you do a natural cycle, ammonia will be high, then converted to nitrite (so ammonia numbers go down and nitrite go up), then to nitrate (so here your nitrite is going down and nitrate is going up). Now, your nitrate will stay high and you can do water changes or wait for algae and such to help bring those numbers down. They will go down without dosing anything if the cycle is done correctly.

I cannot say this is what would cause the fish to die, I just want you to understand that bringing coral into the tank will be difficult to get thriving.

My rule for keeping is never go to chemical means to fix a number. Find the source, try natural solutions, then at last resort use some sort of chemical. I have only ever used chemiclean, flatworm exit, and vibrant in my tanks. Oh, h2o2 a bit too.

So, the fish. Small ocellaris could be anything from stress to disease. The babies can be unpredictable sometimes. I hope the goby makes it. Any pictures? Did the lfs claim to qt? How were the clowns held at lfs (separate tank for captive bred)?

 

[IanD]

Do you think that I should try to re-cycle? I have no algae growth and I'm worried that I rushed the process (didn't want to do chemical treatment but my nitrates were around 100 ppm and LFS said that could harm bacteria?)...I will try to get a good photo of my goby, but he/she likes to sit in the shadows.

For the clowns, they were kept in their own tank and were captive bred.

 

[DeniseAndy]

I would just let it be for now. Maybe a water change. Let the levels come back to normal. If you add anything, I would add some bacteria in a bottle, but that is it. Not sure what went wrong with the clowns though. Maybe wait and see how the goby does before adding more. I wish you the best!
This hobby can be really frustrating and will get you down. If you love it, you will bounce back. Be patient.