Help w/ Fish

[Zyk5280b]

Really stumped on what is going on.

sg. 1.025
Ammonia 0
Trates 0

tank has cycled, and is about 2 months old
40B w/20g sump, skimmer, macro lighting on opp timer.
Not my first tank had a 20L over a year no issues

Started w/ small tomini tang and solon fairy wrasse both eating aggressively and looking good. One morning both dead. All above tests results
Got a clown a week later. 2 days later Dead. Again eating and swimming no signs of any diseases. " " same thing test results
Firefish, a few days later. same thing next 3 days dead.


No fish were showing signs of sickness and just ending up dead the next day. I really dont want to kill anymore fish.
All Inverts(CuC) are fine, Zoas are fine and growing. Sps(relatively new to the tank) have full polyp extension and looking good.

Tank was cycled w/dry rock in display and live rock in sump so I dont think its predation.

Any suggestions? I don't want to keep killing fish.....

 

[evolved]

Do they all die at night? If so, I'd consider your oxygenation. O2 levels drop to their lowest point early in the morning, when pH is at it's lowest.

 

[Zyk5280b]

Ya seems to be the case at night, skimmer runs 24/7 and macro light is on opposite of daylights, i figured there wouldn't be a severe drop in ph. Ill have to check it out though

 

[evolved]

It's really all about surface agitation for O2 levels; how are you in that department? (powerheads, etc)

 

[Zyk5280b]

mp20 on about 90% and creating surface agitation, and a mj 750gph thats also hitting the surface// same with return

 

[evolved]

Well, I doubt that's your problem then...

 

[STL]

Hmm... pH, acclimation method, stray voltage?