I have the opposite problem adam. I cannot keep fish. All my inverts live. But my fish haven't lasted over 3 weeks yet. My tank is 40g with a refugium (about 5 gallons but I used to have a Bak-Pak 2 fish even died with it), a pengiun 280 bio-wheel with cell pore bio-media, and a AquaClear 70 power filter. I have 75 lbs. of live rock and 90 lbs. of live sand. In my fuge I have 16 lbs. of live sand and about 16 lbs. of live rock. I also have shrooms, zoos, and xenia in my fuge. I will have plants in it by Saturday. My xenia has been in there since friday and is growing very quickly and happily it seems. I didn't drip accimilate any of my shrimp and they all lived (1 cleaner, 2 pepper, and 2 saron/monkey shrimp). I also have like 20 scarlets, 30 snails mixed (ceriths, nassarius, one conch, one mexicans turbo, and turbos). I have had two blue damsels die, two green chromis, and recently two false percula clowns. Although two of the six deaths involved powerhead accidents. What could be wrong? My levels are fine. My temp is usually 78 to 80 but never higher or lower than that. Also my salt level is usually 1.023-1.025 and it never gets lower or higher than that. I used distilled water to start my tank and still use it for water changes and top offs. I do 6 gallon water chnages every other week. So what could it be?
P.S.
The fish seemed to become weak. They would in their late days swim very close to the sand bed and sometimes get pulled up against my power heads.