I think I have over 20 at the moment throughout all my setups.. Big pool is 8ft by 2ft deep with water and rays range from 16-24". Leos, motoro, and tigrinus are in a 6ftX5.5ftX18"deep pool which has a lot of top water current making it a little harder for pics. The 3 Leos in the pool together is an amazing site and the motoro is gorgeous as well! Both pools run similar filtrations which are not tied together. Both use Fluval FX5s and a DIY wet/dry and so far so good, fingers crossed. Comments welcome -mike























