RO/DI Unit questions...

Hi Everybody!
Thanks in advance for any feedback.

Okay,
I'm gathering I should spend around at least $150 for an okay RO/DI Unit.
What should I expect in operating costs?
In other words what is the average cost of a RO Membrane?
What is the average cost of DI Cartridges? Is there a standard size? Refills?
I see some that take a carbon pre-block filter...how much are those?

I'm not exactly sure if I'm missing anything else. Let me know if I'm not taking into account some sort of regular cost of running a unit.

Thank you!!!

 

RO membrabes vary on rejection rates and gpd. $55+
If you buy a rodi unit like spectra pure, brs brand, kent, coralife among others yes they are standard. Units from lowes, home depot uses there own brand only. BRS has refills refillable catr.
Carbon blocks depend on micron rating. the smaller it is the more it cost.

The life of the membrane depends on maintence by you, changing sediment filter, carbon filter and back flushing the membrane.

 

Definitely go with a reef brand, the HD/lowes ones are very low capacity and really will be much more expensive in the long term.

BRS, Spectra Pure, Captive purity are all pretty good. How long they last depends on usage. I replace my membrane about every 2 years cartridges every 6 and DI about every 3-4.

 

A good reef quality RO/DI with the bes tof everything is on sale for $120 from Spectrapure right now. www.spectrapure.com. Give it a few minutes, I think they update their site on Sundays.

You replace the sediment filter and carbon block every 6 months, about $12 and $18. The RO membrane can last between 5 and 10 years if you keep up with the above replacements since they are what protects the membrane and the membrane with a matched flow restrictor is $35. DI resin lifespan is entirely dependent on your tap water quality, how well your RO membrane is performing and how much water you make, probably 600-1000 gallons or so with a good reef quality system.

Backflushing a membrane has no proven value and is a way for vendors to take your money and give you a warm fuzzy feeling. Higher quality RO/DI systems use low micron sediment and carbon block filters since they provide the best protection and make the RO membrane last longer. A good DI cartridge like Spectrapures SilicaBuster runs about $18 and will outlast others by at least 30% or more.

 

Buckeye feild supply has some very good cheap ones. Mr. Saltwater Tank has a video on it. He too has a buckeye ro/di water filter.