I built a water change system and am selling it as i took my system down. you can see more here: https://www.reef2reef.com/threads/75-gallon-w-detailed-cost-breakdown.384476/#post-4684525 It consists of: 2 25 gallon containers from Rural King ($134) 4 stage RODI Pro from BRS ($224.99) Pan world 40px pump from BRS ($124.99) plus a bunch of plumbing parts using the nicer ball valves that are easy to use and don't get stuck. All in all the water station cost me $756.24 and it's all documented in the build thread (link above) i attached to it in great detail. it's a little dirty and you'd need to plumb it to your tank still but all the parts are still in good condition. The RO​/​DI media should be changed as well. pickup is in miami (33156), will share my address in DMs with whoever wants to get it.