I have a fairly deep sand bed, I have 1 lb per gallon of display tank, I also have 200 lbs of live rock in a 120 gallon tank. I did have a buncha live rock rubble in the bio ball spot at one time, but i moved them to my nano tank. I might go with that in the future. Thanks for all the great info guys and I appricate the help. I'll drop the check valve and either drill the syphon hole in or just install a ball valve so that when i turn off my pump it dosnt fill the sump up or back anything out of my pump prefilter or overflow my skimmer. Here's a link to the Canister filter I was considering, Its the 375 Filter with UV at https://www.drsfostersmith.com/produ...d=6447&catid=3 and it is surrounded with a 25-micron spun-bound polyester filter cartridge for mechanical filtration. The reason I was gonna go with that one is because I can take the filter out from the top easily and clean it well in tap water. Supposidly they make that version of filter so that the particles dont get stuck in it for easy cleaning, I'm guessing its kinda like the one for my hottub lol. Anyway I've read good things about UV sterilization to kill free floating bacteria and algae, which I hope would help with the overall stability of the health of my tank. If I decided to try it Ace would you recommend me cleaning it once a week or bi weekly or monthly. Should I use a light solution of bleach to clean the filter with then rinse it in tap water or what? If my income tax goes as planned I will have the cash for the refuge and I'll be able to put in a buncha macro algae and mabe some mangroves which would be ideal for me, along with the media reactor. One more question, would the bio balls still trap ditrus if i had the filter sock on there? Thanks a ton again guys, I can't say it enough! Good day~