Royal Gramma not eating?

[nikkifro8994]

My Royal Gramma hasn't been eating for the past 3 days. At first I thought he just wasn't hungry. But today when I went to feed them this morning, I didn't even see him. He usually comes out shortly after the lights turn on. I put the food in the tank and he still didn't come out of hiding which is extremely unusual. I looked around and saw him hiding in a rock. He always moves when my hand gets close to the tank, but not today. I took the net and got him to come out of the rock, but he wasn't moving and was hardly breathing. Now he is laying on his side on the bottom still hardly breathing. I've turned off the lights in hopes that it will reduce his stress. I'll be extremely glad if he survives today.

Tank Specs:
12 gallons tank (~10 gallons of water)
Aquaclear 20 HOB power filter with sponge, carbon, and bio-max
Modified aquaclear 30 HOB fuge with chaetomorpha and a clip on LED light
50 watt heater
2 25 watt incandescent lights
20 lbs live sand
15 lbs live rock (I think)
1 red hermit crab
1 black and white Percula clown - 2 1/2 inches
1 royal gramma - almost 2 inches
Handful of turbo snails

I checked water quality, thinking that would be the problem.
Ammonia - 0
Nitrite - 0
Nitrate - little over 0 but less than 5
pH - 8
SG - 1.023
Temp - 78F

I highly doubt he'll survive because he is barely breathing now. Is there anything I can do? The clown is acting completely normal. But I did notice a hole in my hermit crab's shell today that was not there a few days ago. Could this be related?

 

[geridoc]

This is when the hobby gets demoralizing. Sometimes stuff just happens, and fish die without explanation. This sounds like what is happening now to your royal gramma. Sorry, they are neat fish.