Sick fish

[Vin0302]

Hi
I have recently set up a 30 g saltwater tank. I've had it running for about a month now and every fish that I have put in there has died. Right now in there I have a tomato clown and a long nose hawkfish. The hawkfish stopped eating last night and has been acting weird. I have seen them scrape against glass, not 100% if it's ich. My tomato clown has this gray spot on him not sure if it is a scale or some other disease. Any help is appreciated
Ammonia- 0
Nitrite -0
Nitrate -10
Salinity- 1.021
Ph- 8.0
Temp 74

 

[Sniperhank]

How much rock is in the system? Was the tank cycled? How long have you had the fish and how were they acclimated?

 

[Vin0302]

I don't know exactly how much rock but I would say at least 10 pounds. I used water from my LFS's system to help jump start the nitrogen cycle and then the next days I put in some chromis which lasted like a week. But now the clown has been in there for almost 2 weeks and the hawkfish almost one week.

 

[Sniperhank]

Well there's the issue. Water has almost 0 bacteria in it and will have no impact on the cycle. You will also want to aim for 1-1.5 lbs of rock per gallon of water so you will have enough of a bacteria base to support your livestock.
So your tank might be cycled now, but it wasn't and was causing your issues. Ammonia and nitrite burns gills and is very stressful towards livestock. If you keep your water parameters pristine, all should be well. If you detect any ammonia or nitrite, you need to do water changes to bring those levels to 0.