This is my DIY build sump/refugium that will filter the open part of my 300 gallon Reef. It will have 4300gph coming through plus run eight reacters they are (2) 8" x 36" bottom load bubble towers, (2) 8" x 20" top load bio media filters, (1) 4" x 20" top load carbon, (1) 4" x 20" bottom load bio pellets/pearls,(1) 4" x 20" top load GFO or what ever and (1) 6" x 20" top load Kalk. The back 1" bulkhead will go to my Aqua Medic T5000 Twin Skimmer and the bottom 2" goes to the open flow part of the build Super Dart Gold Pump to UV then DT. This sump will allow me many different ways of R&D with water flow,filtration and reacters. Not all reactors will be used at the same time as there will also be a DIY Algea Scrubber. I have contacted BRS working to get (1) 100lb Pukani Rock for sump. Hope to fire up sump for cycle within the next month while i finish the DT build then will cycle it on it's own before merging the two R&D stuff too Hope you enjoy feed back always welcome!