Sudden Fish death

[justplainnuts]

Okay, I went to the local store to get mysis shrimp for a Dottyback and Clown fish that i purchased 5-24 dottyback and 5-25 clown. When I got back I placed some shrimp in tank, figured it would be a feeding frenzy. nothing, no fish. looked around, noticed clown fish on bottom of tank under an egg crate shelf I made. Moved the shelf and Dottyback was there also, both dead as doornails. I looked at the clown an hour before I left and he looked fine, the dottyback was always hiding in one of the PVC pipes I put in tank. QT tank has been cycled and had filtration. Nothing changed from last time I did tests on water other than the 2 fish added, last night I did feed them some baby brine shrimp and I added the charcoal filter back to tank. I had no air going to tank other than the filters water falling. No idea why these two fish died, I purchased them from PETCO, they looked and acted fine, planned on keeping them quarantined for about 5 weeks. Temp in tank maintains a constant 80. Any ideas what could have caused this? Could they have fought and killed each other? Water Test just a few minutes ago:
Ammonia- 0
Nitrite - 0
Nitrate - 5
PH- 8.0
Salinity- 1.025

Thanks for any help, worried about the QT now....

 

[Tahoe61]

Next time you're at that Petco ask them what specific gravity they run their system at.

I would also try to add some additional means of oxygenation. If the water level is high in the tank than the HOB probably did not provide enough oxygen.

 

[fishroomlady]

^^+1 to the 2 points above. You may want to add in a powerhead pointed to the top of the water in addition to the HOB filter...It sounds like some shock to the system (big change in salinity possibly) or lack of oxygen in the water or both - how did you acclimate the fish to the quarantine? there may have not been sufficient bacteria to handle two fish at once....do you have a biowheel on the HOB?

 

[justplainnuts]

The lack of oxygen makes sense, looked again at amount of bubbles being made from HOB, mot much. Maybe a 1/4 inch drop from filter to water. I will ask about SG next time at PETCO. I acclimated the fish using the measuring cup method, about an hour each fish. I have added a air bubbler to tank now. The HOB doesnt have a biowheel, filter floss and carbon .

 

[eliramos]

next time don't get your fish at petco lol

seriously though always ask what they run their tanks at.

 

[Kworker]

I would avoid the big chain stores first off.

If at worse, order online and test the salinity of the bag and adjust the QT accordingly. If you are using a 20 gal QT it would be smart to have 20 gals of saltwater made and you can always add RO/DI water to dilute.

I would switch to a sponge filter.

 

[Kworker]

Also, drain the QT and disinfect incase they brought in nasties. white vinegar scrub down and rinse than air dry 24 hours.

 

[gpdno]

Well it is quite possible that one or both of the fish were sick from the beginning. Sad for your loss, but you did the right thing by putting them in QT. I have lost fish in QT before and while it sucks, I would much rather lose a few in QT then everything in my DT.