OK, the first thing I've got to say is my tank is being taken over by bubble algae big time. I've tried to get rid of this manually and by critters and neither have worked for me. I'd like to hear from some of you to tell me your ideas. I've even thinking about getting rid of the rock altogether. But new rock cost more than I paid for this. Is there a time range you should replace rock or not? I mean I've had most 10 years. My tank would be better looking without it and I've heard from the LFS tell me why get rid of it. HUH?