[Crangie]

Do air stones in a tank help or hurt a salt tank? I have a 90 gallon that has a fluval 404 canister filter and an aqua clear 110 hanging filter on top. I also have a powerhead (rio 1100) moving the water. Is this enough or should I put an airstone in there too?

[ZIsbell]

What kind of tank is it? i.e. fish only or reef? Are you running a skimmer? Tell us more....

[Crangie]

Its a fish only tank with live rock. I am not running a skimmer but I will be soon.

[ZIsbell]

Yo answer your question about the airstone, they don't hurt anything in saltwater. When you run a skimmer you should have enough aeration from it. You should be fine until you get one. With you running a canister and a hob filter what are your nitrates at?

[ZIsbell]

Also what type of media is in the canister and hob?

[Crangie]

That's the problem. My nitrates are high and I can't keep them down. I have Bio in the canister and charcol in the top with sponges in both.

[ZIsbell]

Theres a real good chance that the sponges are the problem, they are nitrates traps. Try doing away with those, by that I means leave the stuff running but run without sponges. Your live rock should be pretty good at keeping up with the bioload. If taking out the sponges scares you, go to walmart and get a bottle of stress zyme or cycle and put it in the tank at the time you take the sponges out. You might plan doing a water change after taking the sponges out also. What are the trates at?