I am VERY new to the fish keeping hobby and wanted some insight from the experts. I have a 75 gallon tank stand that I build with 8 cinder block and 1/2" of ply wood. The wood is only there so there isn't any pressure point and the last from the cinder blocks, will this be sufficient? Also, how do you guys keep your gravel clean? I have a siphon and clean it out every week but my ammonia always reads at .25. Thanks!