Reverse Osmosis Systems

[Roberta]

The carbon filter ahead of the membrane should take care of the chloramines. At the low levels found in drinking water I doubt that they'd have a bad effect on plants, but they damage the membrane. (Fish are another story, very sensitive). Before you stress too much about chloramines (or chlorine for that matter) I think it is worth "investing" in some test strips to find out whether you have a problem or not... I was concerned about the volume that I was putting through my system (since carbon filters cost a lot more than the sediment filter) until I tested... the levels going into the system are at or below the detection limit of the strips, so I'm not particularly concerned about what the filter may or may not take out - not present in the first place. Knowledge is power... and you can't go on the "general" water analysis from your supplier, it is too broad.

[aerides]

Originally Posted by Roberta

This one may be overkill, but it's reasonably priced, efficient, and has plenty of capacity for you to expand. I have been using it for nearly a year and a half.
GrowoniX GX150-HR - 150 GPD Reverse Osmosis Filtration System

Roberta, I followed the link for the unit you suggested, watched a few of the educational and confidence-building videos that make you feel comfortable enough to buy this thing. As near as I can tell, pretty much exactly what I was looking for. So thanks again. I have very hard water, but softened water will be going into the RO unit. Thinking of going with the higher-flow lower rejection EX200. The video stated that it would yield water with about 20ppm. Referring back to an earlier post of yours, you feel that this would be acceptable for orchids. Ray mentioned that a 3 stage system would be better for membrane longevity, I wonder if having pre-softened water going into the RO system would lessen this impact.

[Roberta]

When I first got it, they put the wrong membrane in it, got the high flow version and I was getting more like 40 ppm. They swapped it out. The only difference between the two is the membrane, they're interchangeable. So if the high flow one is giving you more TDS than you want, just get the other one and swap them out. Do stay on top of flushing the unit with the backwash valve that it comes with. Ray is right, the lower ratio of waste to RO does reduce the life of the membrane, but a daily (or every few days depending on usage) backwash for 3-5 minutes helps a lot without wasting very much water - lot less than a 4:1 unit would generate. Watch for sales on the various components... you can save a few bucks.

[Ray]

If you have softened water, you definitely need to get the salt out of your irrigation water.

Flush-to-pure ratio actually has very little effect on the purity of the outflow; the higher the incoming TDS, the higher the outgoing TDS...simple as that.

If your water supply is chlorinated, you will need a 5-stage system: (sediment>carbon>carbon>membrane>polishing) A 4-stage has one less carbon filter.

Be sure to purchase a unit that uses standard components. Proprietary ones get expensive, and with standard ones, you can always run to Home Depot of Lowes to get replacements, if you don't want to wait for mail order (but you WILL pay more for them).

As I said earlier, give a LOT of thought to water storage and delivery. Estimate how much water you use per heavy watering of your entire collection. I did so by timing the watering process, then filling up 5-gallon buckets from the same hose, for the same length of time, to measure the volume. Your storage tank should hold about double that. Then, using the frequency of watering, you can determine your average daily consumption. Your RO system should have a capacity at least double that - don't forget that with lower pressure and temperature, it will not put out at 100% of the rated capacity.

If you go with a pressurized tank, that can propel the water for irrigation. If you opt for an open air tank (think plastic drums; often free from your local car wash), you'll need a pump to propel the water.

[aerides]

Originally Posted by Ray

If you have softened water, you definitely need to get the salt out of your irrigation water.

Flush-to-pure ratio actually has very little effect on the purity of the outflow; the higher the incoming TDS, the higher the outgoing TDS...simple as that.

Be sure to purchase a unit that uses standard components. Proprietary ones get expensive, and with standard ones, you can always run to Home Depot of Lowes to get replacements, if you don't want to wait for mail order (but you WILL pay more for them).

As I said earlier, give a LOT of thought to water storage and delivery. Estimate how much water you use per heavy watering of your entire collection. I did so by timing the watering process, then filling up 5-gallon buckets from the same hose, for the same length of time, to measure the volume. Your storage tank should hold about double that. Then, using the frequency of watering, you can determine your average daily consumption. Your RO system should have a capacity at least double that - don't forget that with lower pressure and temperature, it will not put out at 100% of the rated capacity.

If you go with a pressurized tank, that can propel the water for irrigation. If you opt for an open air tank (think plastic drums; often free from your local car wash), you'll need a pump to propel the water.

Thanks. I was confusing a 3:1 ratio with a three-stage system. Roberta's is a two stage system. My water is much "harder" than hers. Do I then need a three-stage system? Or does the ion exchange from my softener do some of the work before going into the RO system? Hope I'm not asking stupid questions. This is all new to me. Thanks.

[Ray]

The system in Roberta's link is a three stage system: the water first passes through a sediment filter, then carbon, then the membrane. The only thing that differs from a residential 4-stage system is the lack of a final, carbon block, polishing filter, which really isn't all that necessary for plants.

The number of stages has nothing to do with hardness. If your water supply is chlorinated, your softener does nothing to change that, so an additional carbon filter stage before the membrane is recommended. Modern membranes are far less susceptible to chlorine degradation than they use to be, but it hasn't been totally eliminated, so why risk it?

[aerides]

Originally Posted by Ray

The system in Roberta's link is a three stage system: the water first passes through a sediment filter, then carbon, then the membrane. The only thing that differs from a residential 4-stage system is the lack of a final, carbon block, polishing filter, which really isn't all that necessary for plants.

If your water supply is chlorinated, your softener does nothing to change that, so an additional carbon filter stage before the membrane is recommended. Modern membranes are far less susceptible to chlorine degradation than they use to be, but it hasn't been totally eliminated, so why risk it?

My water is not chlorinated. It's well water. I guess I'm good. Thanks!