fish loss

[mymicroreef]

I recently had two fish die within a day of each other and am at a loss for the reason why. They were a Kole tang and a white sleeper goby. My tank is a 30g with around 40lbs of live rock, 1-1.5in of sand, and a separate refugium with 25 mangroves and cheato. There are numerous hermits and snails. There are no other fish in the tank. The fish were added about six weeks prior to their passing. They were both very active and eating well. Any insight into the cause would be greatly appreciated. Thanks.

 

[Tonynlo]

What are your parameters? Ammonia and nitrite should be checked first.

 

[redrider911]

How old is the tank? When did you get the fish?

 

[mymicroreef]

Ammonia and nitrite are zero, nitrate is 5ppm. The tank has been up and running for 15 months. I had damsels and clown fish in the tank for months without a problem.
I purchased the two fish together about 6 weeks ago. I did notice about a week before the tang died his color became much lighter in the morning but would darken a little as the day went on. I suspected he was stressed but didn't know why.

 

[Jacwil]

Hmmm...you said cuc was fine right? It's a FOWLR setup (fish only with live rock)? No corals that seem to be affected by anything?

 

[sland]

Were the livestock eating well before you got them and QT'd at the store? I will not purchase anything without seeing it eat numerous times and sit in the store for a while. Healthy livestock is priority one.

 

[Gary Majchrzak]

it's tuff to diagnose this without having more info on your aquarium.

IME fish are (usually) fairly difficult to kill at the same time. Something is amiss.....

 

[museumguy]

One possible cause that is often overlooked in a case like this is temperature swing, either too warm or too cold. A 30g tank will be a lot more vulnerable to temp swings than a larger tank. Any changes to heaters, lighting, etc that could alter the water temp?

 

[mymicroreef]

Both fish appeared very healthy when purchased, although I did notice the tang had a couple small scratches on its one side. They seemed to have healed in about 8-10 days after bringing him home.
Tank has no corals except for a couple aptasia. Tang was eating very well and the goby was moving quite a bit of sand. Fuge has alot of amphipods, some large (1cm). Temp swings may have been an issue. I had two heaters in tank (one as backup) but I did notice temp would fluctuate between 77-81 deg.

 

[5380]

In the last week did you do any maintenance to the tank?

 

[Jacwil]

Yea that temp swing is minimal and isn't the culprit. Use any strong chemical cleaners near the tank or can you think of any contaminant that could have gotten in there?

 

[SushiGirl]

I suspected he was stressed but didn't know why.

A Kole tang should be in no less than a 55. Maybe it was stressed & died, fouling the tank & killing the goby. Water changes happen fast in a 30 gallon.

 

[Gary Majchrzak]

30g is small for any Tang.

Does this 30 have a skimmer on it?
I would rule out temp as long as it stayed between 70- 84F

 

[mymicroreef]

Tank has a skimmer, removes wastes well.
The tang was small, ~2in. Goby ~3in.
The tank is in my sons bedroom and I'm suspecting it may have been contaminated by aerosol spray (deodorant, cologne).
Do you this may be the cause?

I try to do water changes every two weeks, 3-4 gal.

Thanks for all your replies!:spin2:

Bruce

 

[Gary Majchrzak]

sounds like contamination is a strong possibility

 

[mymicroreef]

I'm filtering through activated carbon in hopes it doesn't affect other tank inhabitants. Snails and crabs seem to be fine right now. Looks like I'll move the tank soon.

Thanks again everyone.