Water changing system and RO water storage with a 1344 gph Iwaki Pump. Two 55 gallon drums. Pump will flow water from one side to the other or mix your salt water. Can also pump water to your tank. $150 for everything or $100 for two drums and plumbing. Pump alone cost over $300.
https://www.bulkreefsupply.com/iwaki-md-40rxt-japanese-motor-1200-gph.html
https://www.bulkreefsupply.com/iwaki-md-40rxt-japanese-motor-1200-gph.html
