RO units

[rica5tully]

What difference is there between a 3-stage and a 4-stage RO unit? Is it worth the money?

I only have a 55-gallon tank. It seems like I should get the smallest unit (25GPD) since it's cheaper and the replacement cartridges are cheaper. Is that true?

BIG QUESTION: Based on running 16 gallons a month for water changes, how long will the expensive membrane last before it needs replaced?

Thanks!

[Guy W]

3 stage has the following:

1 Sediment Filter (usually like 1 or 2 micron)
1 chlorine filter
and the RO membrane

The 4 stage adds a Deionization filter.

I think a 3 stage will get your water something like 95% pure, while the DI will bring it up to 99%. I went with the DI but I don't know how necessary it is.

The membrane I'm told will last years under typical use. But i'm not 100% sure on that.

Guy

[BrianH]

Remember that the GPD rating on these units is under ideal conditions. IME, you can expect to get about 50% of the GPD rating. With the unit you are talking about that is 12.5 gallons per 24 hr period. I would shell out some more cash and get a larger unit. Especially if you ever plan on expanding to a larger tank or adding more tanks. I bought a 100 gpd RO/DI unit from air water ice (http://www.airwaterice.com) for under $200 and am totally satisfied.

Brian

[rica5tully]

Thanks for the advice

I was thinking about getting the "Mighty Mite" from Air Water Ice. It's only 20-50 GPD but it's also only $100 (with DI)

I agree that it wouldn't hurt to go bigger. My concern, though, is that I'm going to be running it from the sink. Is the big one you bought too big to just hook up to the sink every two weeks?

[rica5tully]

BrianH,

Regarding the 100 GPD you got from Air Water Ice. Did you have that installed? Or do you just use it from time to time and hook it up to the sink?

ET

[BrianH]

Rica,

I used to just hook it up to my slop sink once in a while, but this can be somewhat of a pain. If you don't connect it perfectly you can get a tiny leak and I think that the pressure that builds will eventually ruin the faucet.
While we were having some plumbing work done I had the plumbers hook up the RO/DI. They had a great idea. They ran an ice maker connection(a good one that is soldered to the pipe, not the kind you poke a small hole in for water)for me to hook up the filter. Now I can filter about 1 5gal bucket every night in about 2 to 2.5 hours.

Brian