Reverse Osmosis

[Aaron]

I use the the DOW Filmtec replacement RO membranes. You can find the 75 gpd for about $30.00 each on ebay.

I started using RO when we moved to our condo a few years ago. The tap water here is too hard and I was spoiled on my old well water that came out at 6.7 ph, KH 1 and GH 10. It was perfect for plants.

I hadn't been mixing mine, just doing water changes. I just started mixing it 3:1 RO to tap. I'll report back how it goes.

[DelawareJim]

Another alternative is a DI or De-ionization system. I used one at home when I lived in Delaware since I paid for both water and sewer.

It was a 2-chamber system that separated cations and anions. The nice part about it was very simple to use and it produced no waste water. I used the colour change media and recharged the spent media with Muriatic acid and lye I got from my local pool distributor.

Now you can find places that sell and recharge the resin in bulk.

Cheers.
Jim

[Aaron]

Another alternative is a DI or De-ionization system. I used one at home when I lived in Delaware since I paid for both water and sewer.

It was a 2-chamber system that separated cations and anions. The nice part about it was very simple to use and it produced no waste water. I used the colour change media and recharged the spent media with Muriatic acid and lye I got from my local pool distributor.

Now you can find places that sell and recharge the resin in bulk.

Cheers.
Jim

Hmmm... I wasn't aware you could use just the DI part of the system. Is there still a sediment and carbon prefilter with that type of setup?

[DelawareJim]

Aaron;

Actually my system is an old Kent Marine Deion 200. Carbon block pre-filter, cation, and anion chambers. I'm sure you could run it as a sediment pre-filter, carbon block, mixed resin setup too.

http://www.kentmarine.com/products/deion-200.htm

Cheers.
Jim

[Aaron]

Another option is to use a dual stage RO filter where the waste water from the first membrane is put through the second membrane to be filtered again. This produces more like a 1:1 or 1:2 pure water to waste water ratio.

You need at LEAST 65 psi at the first membrane for a system like that to work well or you'll have to also get a booster pump.

[Aaron]

I was thinking about this some more the other day, wishing I had the ability to do auto water changes. Why not just use the first few elements of the RO filter, the sediment filter and carbon filters to do your water changes with? Then you don't have to worry about residual medicines, chloramine, etc. in the water and the minerals stay in it for the plants.

[eleontie]

That will work just fine for regular water changes.
A question to ask is if the carbon filter is better or worse at removing chloramines than the dechlorinator ... With small gradual water changes a planted tank will do fine with both anyways, but it would be nice to know.