Is this a good RO/DI Unit?

Hi all! I just bought a factory refurbished unit from Spectrapure. It's the Maxpure MPDI unit. The add said it's a 4 stage unit, but it only has 3 clear chambers. Is this sufficient purification for my tank water? (The 4th may be the opaque tube running across the top of the other 3. The manual says it's the membrane housing) Reading about this unit is like reading a foreign language to me as I know almost NOTHING about RO/DI's. It's a 90 gpd unit.

 

you did great, SpectraPure are the best RO/DI units IMO, many will agree. Those 90gpd refurbished units are a steal, I own a Spectrapure 90gpd already and may even grab another at the great price they offer them. Love mine, it's super easy to use and the membranes/filters are the best and last a long time.

 

I just bought the same unit. Its great. If you have any questions you can post them in their forum here on 3reef or call the tech department, they are very good at answering any questions.