Some fish dying.

[RanRod512]

My tank (56 gallon) has been running well for almost a year. Not too long ago, I lost 2 fishes. Before that, I lost both a cleaner and peppermint shrimp. After some research I determined a pistol shrimp that hitched into my tank was the culprit. I removed the shrimp. A few days ago, I added a gold head sleeper and a BTA. Yesterday, I noticed my red mushroom shrunk, my frogspawn wasn't inflating like it normally does, and the sleeper wouldn't come out its borrow. Today I notice I a fish (some type of goby) is no where to be found and the sleeper is dead. I also noticed a foul order yesterday (most likely the dead goby). My Ammonia, nitrates, and nitrites are 0. pH is at 8 (always is). Also realized I was over due on changing the filters on the RO/DI water filter. Only fish alive are my 2 clowns, a six line, and a bangai cardinal.

Any ideas whats killing certain fish?

 

[skene]

You probably disturbed the sandbed lifting up noxious gases and created a spike.

 

[Chiefmcfuz]

Do a large water change then several small ones ove the course of the week and make sure to run carbon frequently changing that as well.

 

[RanRod512]

You probably disturbed the sandbed lifting up noxious gases and created a spike.

I did clean the build up that was between the sand and the glass, three days ago. I've never done that.

 

[RanRod512]

Do a large water change then several small ones ove the course of the week and make sure to run carbon frequently changing that as well.

I have 10 gallons cooking up now. Thanks

 

[sharkbite]

Did u check your salinity ? Also check phosphates for the corals. Probably a good Idea to do a water change.

 

[Dre]

I have 10 gallons cooking up now. Thanks

Cook up another 10 gallons.

 

[RanRod512]

Did u check your salinity ? Also check phosphates for the corals. Probably a good Idea to do a water change.

*head nod* Yup. SG @ 1.26. Thanks

 

[RanRod512]

Cook up another 10 gallons.

Copy. Thanks