RO Water

[Gin]

Hi Nan .. Firstrays has it here is a link .. I have not found a local place to buy it .. Gin

Welcome to First Rays Orchids

[Nan]

Thanks for the link!
Nan

[Ross]

I have a whole house softener and added an RO unit for drinking water. I get it serviced and tested once a year. A softener simply replaces the mineral content of the original water with sodium chloride in the exact same concentration as the original minerals it is replacing. So if you start with 300 PPM of calcium (for instance) you will have 300 PPM of sodium which "feels" softer to the skin. It is "death" to house plants! An RO unit will remove most or all of the dissolved minerals, be they sodium or calcium or anything else. Better RO units should remove minerals down to <2 PPM dissolved minerals if they are operating at high effeciency. Due to the nature of distilled water (often distilled by condensing steam), it contains 0 dissolved minerals. I used to add tap water to buffer the RO water, but have settled on MSU mix for several reasons and am getting great response from the 'chids.

[Ross]

Originally Posted by justatypn

Distilled would be a great option, I am not so sure you need any special fert with week weakly and a monthly fresh water flush you should not have any problems...just my 2 cents worth.

I really have to disagree, sorry. Distilled and pure RO can be very hard on orchids (and other house plants) due to the tendency to disolve and carry away any minerals in the potting medium/soil. They really are a "universal solvent" due to not carrying any additives of any sort and over a period of time may actually harm the orchids. If you don't care to use specially formulated mixes of fertilizer/additives, then at least mix some regular (unsoftened) water in to help buffer the water.

[Nan]

What about bottled spring water? Is that a viable option? My problem is, I think all our water (including that from outdoor taps) goes through our water treatment/softening system. So...I have to purchase water for the orchids. I guess my choices are either distilled water with MSU added...or bottled spring water with a regular weekly weakly fertilizing routine.

[Ross]

Spring water is generally OK, except it may contain high amounts of dissolved minerals.

[markr]

I grew orchids for several years with "pure" RO water and they did great. I usually added fertilizer to it though. If you water exclusively with RO water you'll need to supplement calcium and magnesium on occasion or your orchids will definitely suffer. Be sure one of your fertilizers of choice has these elements in it.

I think rsfrid is correct about the dangers of 100% distilled water, but not sure I agree with him about RO water. Perhaps it depends on how effective your RO filter is, but few affordable ones reduce mineral content by more than 90% or so. In any case, most people are adding stuff to their orchid water anyway.

I don't use RO now because my local tap water is very soft. Also, RO systems waste a lot of water. For each gallon of filtered water you produce, you're flushing 3 or 4 gallons down the drain, which is difficult to justify.

[Ray]

If your RO system is up-to-snuff, it's essentially the same as distilled - the minimal amount of passed-through minerals are insignificant - so they may be treated as the same.

Using pure water of any source on your plants not only strips the hell out of the nutrients in the medium, if continued, will strip them from the plants, too.

Not only that, but as the residues in your medium dissolve in the pure, unbuffered water, the pH in the root zone could swing so wildly that it could be damaging to the roots.

As to the water "wasted" with an RO unit... mine helps humidify the greenhouse and keeps a small pond full just outside of it (the frogs love it). In both cases, the water ultimately seeps back into the ground, which is where it came from. For folks who don't have that option, there are "zero-waste" RO systems available now, and old ones can be converted by adding a pump that pressures the water through with no flushing. I imagine one must replace the filters and membrane more frequently, but at least you're not "wasting" water.

[SARA A]

this is great stuff