New to RODI

[Buckeye Field Supply]

A 75 gpd membrane with a proper flow restrictor will still produce apx. 4 parts waste water to 1 part purified water, so it's no more "efficient" in this regard.

What a 75 will do much better however, is clean the water. Here are some spec's for you (the 24 - 100 gpd membranes are Filmtec brand):



Russ

[gregzz4]

Thanks for that Russ. I don't believe Vertex's claims of 98% rejection on the 100gpd I bought, but with 8ppm in and 0ppm out, guess it doesn't matter anyway. Makes me wonder if I'll ever need the DI.

[mike31154]

On the other side of the coin, if your source TDS is consistently that low, you could simply run it straight through DI only, ditch the RO membrane altogether. Water production may be a lot quicker in that case, although not sure if contact time going thru DI is a factor, probably is. Don't necessarily recommend you do this, but I always like to look at things from a different angle. With an oversized cartridge full of DI media, or even a number of standard DI cartridges in series, you could probably get a good amount of 0 TDS water for your tank before the DI is depleted.

[gregzz4]

Thanks for the thoughts Mike, but we'd like to drink the water too

[hillegom]

T off before the DI for drinking. Tastes better.

[gregzz4]

Besides the fact that RO tastes better than DI water, DI can cause serious health problems.
If you look at my build thread, you'll see my RO and DI are valved so I can bypass the DI.