What type of filtration do you guys all use?? And which do you think is best for rays? Ive heard everything from bio wheels to Fluvals and sumps.. Is there any type of filtration that can ease the pain of water changes? Ive also heard something of a drip system?? Also, do you guys all let your water sit? Or use the prime?I have no way to let 500+ gallons sit and age..Never was a problem with my one ray tank, but Ive now got total of 8 ray tanks set up and its getting old.. Any ideas?