No one would put a reverse osmosis system after a sodium softening system. The drinking water system will be fine to use on orchids. Rather than try to fortify R/O water haphazardly by adding epsom salts which adds magnesium only but does nothing about calcium why not use a balanced 'complete' fertilizer made for use with R/O water.

H

Thanks howard! good to know that people generally don't put reverse osmosis after sodium softening. I feel like it's incredibly wasteful to use the R/O water for watering all my plants so I'll work on finding a way to grab water before it enters the softener, but it's good to know that there is an alternative.

I've been using the same fertilizer (Schultz Orchid Food 19-31-17) for ages, but I don't *think* there is any calcium. I feel like pure tap water has a bunch, but R/O water probably doesn't...I'm starting to think I'll need to save some of those eggshells...

I have the same set-up, water softener/RO. The RO is water directly from the well (we have well-water). I use this on my plants. If you have an outside hose, it will be water untreated by the softener. No one treats water that goes to the outside hose. I use the hose water until freezing. I mix half hose water and half RO. I also have a rain barrel which I use in place of the RO, but that freezes in winter and I then go straight RO. My RO system is under the kitchen sink and holds 3 gallons.

Hope you could follow all that,

Jane

According to the literature that came with my r/o system, it actually works better when fed with softened water. No explanation for why, but that's what it said. It didn't make any distinction between sodium or potasium softened water, or any other kind. Might be worth a little googling to get more info.
-MB

I don't understand why you would put an RO system onto a soften water system. Doesn't make sense. The RO is doing double duty. You WANT to remove the salts. Especially sodium. RO system is only necessary if you have real hard water problems, well water, dissolved metals like iron or highly alkaline salts. Most drinking water is fine for watering orchids, but it also depends on where this water is coming from. It is a good idea to have your water tested before installing a RO system. Some plants like certain phrags and disas are very sensitive to hard water, and do require RO or even distilled water to grow properly.

Thanks for the details, tee. Yes I'm quite sure the outlet in the yard is plain tap, but as Jane mentioned the tap outside freezes, so winter is going to be a real problem. I'll have to check whether our R/O is after or before the softener - we have the similar setup under the kitchen sink, so I will check that.

Hi Jane,

In response to your statement "No one treats water that goes to the outside hose" all I can say is don't say "no one". The idiots who installed the softner in my house didn't want to spend the money for the plumber to separate the lines. Consequently, ALL of my pipes have softened water in them unless I turn the softner off.

Calvin,

As I mentioned, I turn my softner off and then use the untreated well water to water all my plants. As my orchids are all upstairs in 2 spare bedrooms, I use the tub faucet to fill my watering can and soaking buckets.

Penelope

We have the same setup, RO water in the kitchen (via special faucet), softened water in the rest of the house, plain old city water outdoors. I've been using a sinkful of a combination of kitchen RO water supplemented with half outdoor tapwater when I water/feed my indoor plants (mostly phals and African violets). No problems so far.

We just had the soft water system tech out for a checkup of the system (replacing cartridges, checking the softener, etc.) and during his instruction on how to backflush the kitchen RO system, he mentioned about not doing something in particular that would add the softened (salt) water back into the system. He even tested the output RO water, and it was pure as it could be.

I'm convinced it's safe to use the RO on your plants (sure does drain the little RO tank fast, though!). Might want to consider getting a small container of MSU fert designed for RO water use, in order to put all the "good" chemicals back into the water for the plants.

Easy way to test your outdoor water to see if it's conditioned--get a tender houseplant like an African violet and use that water only for a couple of months. Softened water will kill it off in short order (speaking from experience here). Of course, if your outdoor water is very hard (as ours is), you'll also get a ton of mineral buildup on the plant. Worth a try.

Sharon

I apologize for my previous post. My RO is under the sink and receives the softened water. My water softening is with Potassium rather than salt. I could never get a good answer as to whether that is a problem with plants. I use straight RO on my plants during the winter. As Sharon mentioned, I use MSU for pure-water. Before the outdoor water freezes, I mix the hose water with the RO.

I had problems with our well water and orchids. Changing them to RO made quite a difference, not only with orchids, but many tropicals also. I just don't like being so limited to this one fertilizer. It is the only one I could find which was developed for RO water.

Jane

Thanks for all the help..it's been a while. I've just used the RO water with the MSU fertilizer and everything is fine. My RO water does use the softened water as a source, it seems.

Calvin, since it seems to be a recent addition, why not call the company that installed it and ask them a bunch of questions about which line is softened and is there one which isn't, can they give you a separate tapwater line for a reasonable price if there isn't one (probably cheaper than buying water for years); explain your problem and ask for a suggestion or two. They probably use the same set-up in all of their home installations. I have found most contractors and manufactureres of all types to be very helpful if asked nicely.

Having been in the "salt business" first most water softeners use sodium chloride table salt, the calcium and mag chlorides are displaced by the sodium chloride. Plants don't like the sodium chloride. They are fine with the mag and calcium Epson Salts are MgSO4 I'm not up on my solubility index but unless you had a really saturated solution, which you don't this wouldn't work.

A few years ago I looked at a water softener that used Potassium Chloride. The idea is that you wouldn't have the sodium problem, instead of sodium chloride you just bought potassium chloride. I never could get anyone to say what the effect would be on the plants though I know that potassium is okay. Prehaps someone would comment, if this would work then you could get the system switched over.

Otherwise - use the RO water - you don't get the chlorines but you do need to use the fertilizer for it or add back in the mag and cal. MSU formula for RO water has it.

Can you go to an aquarium store and get a test kit that would indicate if the water has added salt or not? I use one to test the ph and stuff of r/o water before I put in the fertilizer and after I put in the fertilizer, and the same for half r/o and half tap before and after adding fertilizer.

Oohey! WHAT a controversial subject! I'm afraid I am a Hassidic Jew on this subject. I would not trust ANY water that comes from a public supply system, treated or not. This water is basically recycled sewage and God alone knows what chemicals it contains to "purify" it. I am EXTREMELY lucky in that I can use exclusively rain and well water.

Calvin, is it out of the question for you to use rainwater in the summer and bottled spring water in the winter? You told me you don't have a lot of very large orchids. Spring water is great as it contains a lot of micronutrients and is a lot cheaper than putting in an expensive R/O system anyway.... Happy New year.

I have to agree with Penelope14 in regards to the statement "No one treats water that goes to the outside hose", as when my whole house water softener system was installed, they installed it directly on the output from the water meter, which means that everything (lawn included) gets soft water (unless I bypass the softener by turning 4 valves). We also have an RO unit under our kitchen sink for drinking water & which feeds the ice cube maker on the fridge but I can't determine whether the RO unit removes the sodium that the softener uses to replace the Calcium with. Does anyone know the answer to this question?

Hi! RO systems removes sodium from the water as well as chloride and other salts. RO systems sometimes need a softner before because hard water (high concentrations of Ca and Mg) damages the RO membrane. If free chlorine is on tap water (as is normal in water distribution pipelines) an activated carbon filter should be added also before the RO system to avoid damages in the RO system. Regards, Juan

We have a softener system that softens the house water so the there is effective laundering, and no mineral staining of tubs, sinks, and showers. There is a point of use RO system and a special drinking water tap next to the kitchen sink so that those of us who don't need extra sodium can drink water. In the garage, our drip line irrigation system splits off from the house water upstream of the water softener so Im sure that I am not putting salty water on my plants. Or in my body.