Ri di

[thegame1]

The best place to buy RI DI.

[mike_cmu04]

Try your local reef forums for someone selling one you can usually find one alot cheaper than new ones. If you want a new one try marinedepot.com

[RedM3]

Do you mean RO/DI? If you mean the actual water itself, try your LFS. If you meant a RO/DI system, see Mike's advice above. There are plenty of other retailers that sell them new, but I don't have familiarity with many companies other than Dr Foster's and Smith - which has been great.

[GT_Jacket]

I have been very happy with the replacement cartridges/resin from BRS. I'm sure there entire units are of good quality also.

[Sk8r]

Bear in mind a good ro/di filter system is portable, doesn't need to be permanently plumbed in, and it will pay for itself over time---and pay in terms of a healthy tank.

[Michael]

as sk8r mentioned and to add to it, ensure you keep it wet even if not in use.

[89Foxbody]

The Bulk Reef Supply one is great. I'm planning on getting it soon.