I think of of my True Percula Clownfish is dying, why?

[hulkzilla]

Came home from work today and noticed one of my True Percula Clownfish is at the bottom laying on it's side breathing heavily. I reach in with the net or my hand and he'll jolt away then go back to laying on his side. I had to turn off my circulation pump because he was getting blown around the tank. Here is my most recent test two weeks ago:
Salinity .026
Alk 12.6
Cal 480
Mg 1350
Ammonia 0
Nitrate 0
Nitrite 0
Phosphates 0
PH 8.0
I added two True Percula Clownfish to my tank 2 weeks ago and feed them twice a day. I change 25% of the water monthly. It is a 20 gallon tank with live rock, no sand. I've had the tank since November but had to basically start over in February because of bad advice from a store I don't go to anymore. So, does anyone have any idea what could be happening?

 

[aquandrew]

could be over feeding and not enough water changes

 

[hulkzilla]

going out right now to get 5 gallons

 

[boosted_msp]

If he's got excess slime it could be brook. I recently lost two occelaris from this

 

[TheTodd]

Does it show signs of anything beyond the rapid breathing? Spots, coat of mucus, anything out of the ordinary? Other fish acting normal?

How is surface agitation?

If ammonia/nitrites/nitrates are all zero, I'm guessing its not lack of water changes.

 

[hulkzilla]

No slime

 

[hulkzilla]

Well, the fish died a while ago. the other one seems fine. Some other sources suggested to cut down to feeding once a day. surface agitation is good. Everything was find when I left for work this morning. I went out and got 5 gallons and did a test, everything came back fine.

 

[TheTodd]

Overfeeding should not kill a fish directly or cause it to act that way though. Overfeeding could lead to high nitrates, which is bad, but you are saying yours are at zero. Most fish are fine with being fed every other day. I've done that with all my tanks for years and never had problems. Watch the other fish for signs of anything out of the ordinary.