I have one of those coralife units. I bought the 25 gal and add-on DI unit. They are not as bad as some make them out to be. They are made with all standard size parts. That means that you can get the filters anywhere and they will fit. I have bought replacement RO, Carbon, DI filter from Buckeye and they fit without any problems. I fact I bought a larger output RO works without any problems.

I do agree that Buckeyes prices are very good and he is very quick to answer your questions.