Total Failure

[Fox]

I am at my wits end...Since starting the tank and being very patient with the cycle, I slowly added my fish (2 blue Chromis which did well) Then I added 2 clown fish and a manderine dragon goby.

The clown fish died, and I still haven't found the maderine goby. I had my water tested by my LFS and was told my water was fine and that they were just bad fish.

So I tried again...3 more clown fish and a Royal Gramma Basslet. All very compatible and hardy fish from my research and they all got along.

First went the Royal Gramma and a clown, and now within 12 hours my last 2 remaining clowns died within 12 hours of each other which leaves me with 1 green chromis as of this morning.

I should mention that all my snails and crabs are doing great as well as the few corals (zoa, candy cane and my green star polyp is doing great). I put in an LTA a week ago and he is fine as well...

I tested my water last night and although I dont have the readings the only thing that was a bit low was my PH which I have been using Buff to raise...

I am at a loss and ready to give up on keeping fish on account of incompetence and just keep corals and snails

I just don't get it.