Explain wierd fish deaths?

[IndyMathWizard]

2 months ago I got adventurous and took a 10 gal tank that had been sitting around and turned it into a nano-FOWLR. 13 pounds of LR, 1 inch of sand from my main tank, kept an eye on it, no cycle. I put in a perc and a blood shrimp. The perc lasted two weeks. Then I tried a 2" Cherub Angel. It lasted a week. I finally decided to go easy and I put in a Domino damsel 2 1/2 days ago. Dead this morning. And the shrimp? Alive and well, eating healthy, everything. Here it is:
10 gal tank
13 lbs LR
1 inch CC
AC Powerhead 301 w/ a Quickfilter on it.
81 degrees F, VERY constant
pH 8.2
Amm 0
Nitrite 0
Nitrate <10
Salinity 1.019

There are also 2 snails, both been fine since day 1. What the
*&^% is going on?

[SurferStevo]

You say the inverts are okay, huh? That's strange usually they are more sensitive to anything that might be in your water. The only thing I can think of is that you might bump up the SG to NSW levels. Do it SLOWLY.
I had a similar problem once. It turned out that my water was so tweaked that even though everything was alive. I could not add a new fish - they did fine in the q-tank, but once in the display they were dead in hours or days. I just gave the tank 3 months with out adding anything new & just doing water changes.
Have you got a skimmer (maybe a spare prism) to put on the tank?
Maybe someone else has a better answer to this one.

[SeanT]

Hmmm tough one.
Is your water being properly oxygenated?
The fish could be suffocating.
Shrimp do not require as much O2 as fish.

[odoprelude]

was there any strange behavior in the fish? how long after you introduced the fish did they die? I had an outbreak of brooklynella in my tank and after remaining fishless for a month and a half, everything has been going fine (knock on wood). My fish would die within three days after I introduced them... start shimmying and die. My water params were fine and the inverts were doing great....just my .02

[Crazygirl]

how long did you acclimate them? and did you get from LFS (how long did they have them in there tanks) or on-line?