I am new to this saltwater thing and I have a problem. I believe I have a high nitrate problem. I do regular water changes on my 55 gal once a week. I do about a 20% change or about 12 gallons. My tank and system is about a year old and I use a wet/dry filter system with the bio balls. Is there a period where the bio balls either need to be replaced, cleaned or removed and replaced with live rock? I believe the bio balls are causing me my high nitrate problems cause now it seems like everyone in the tank is stressing. So what do I need to do to my filter system to get everything in check and save evryone else from stress.