I already have a running 125 rock sand and all. Been a reef tank for about a year now. Going to consolidate a lot of it down to to my new 56 gallon. Still leaving some LR and LS in the 125 tank. I just want to go a different route with it. I wanted to give the predator tank a go. It wouldnt be a long term commitment cause the army will be moving me in about a year most likely. So the shark and ray wont have a large amount of time to grow to full size. so a fluval and oversized protein skimmer should surfice you think? I appreciate the input.