Something going on with my reef fish

My reef is about 4-5 months old and for the last two months I have purchased several fish two at a time. The first will die in a week or two and I go and buy more. The fish are Damels, and Clarkii and Chromis and a Scooter. the scooter, I have had for 2 weeks and still alive.
The reading on every test is very good. PH=8.0-8.2, KH=10, Phos=0, Nitrate=0. The only oxygen is from 2 small water fall from a hang filter and a refug return.
Hope some one can help. I need fish in my reef.

 

What's your nitrite and ammonia? How much rock do you have? Do you have any powerheads? Do the fish look healthy at the store? How do you acclimate them?

 

I don't have a nitrite or amonia test kit. I also don't have any fish and what few corals I have are all frags. So where would ammonia come from? I have a circulator pump and as I said, a hang on filter and a flow from the refug. The fish looked great at the store and the day they died, except their month was opening and shutting quickly. I have 30 lbs of live rock in a 20long tank. They are acclimated by adding alittle water from my tank and removing a little of theirs about every 30 minutes. Thanks.

 

one possible source is the rock itself. it's important you test for ammonia and nitrites. Especially in the first 6-9 months to make sure it's stable at 0.

 

if they are opening there mouth alot and closing it that may mean not enough oxygen in the water imo. maybe point a powerhead at the surface to aggitate it more.

 

Did you cycle your cycle your tank at the start. if the fish u add die quickly and you take them out there may not have been a cycle yet. did u start with live or base rock?

 

Do you have a skimmer? if not get one.

 

i think this is an oxygen issue, a skimmer would solve it, if you cant afford one just get a punp and a limewood air stone.

 

I'd def start with getting ammonia and nitrite test kit as said above and make sure they are both at zero. If that is the case then I'd have to say you need better gas exchange as said. A power head at surface or skimmer will give you good o2 also. Do you have the top of your tank open or is it covered? How are the frags in your tank doing? If ammonia is present they would show signs of stress.

 

I am making the assesment that it is that they are all Damsels (with the exception of the Scooter). Damsels will get real territorial and pick each other off.