Tap Water for monthly flush?

[Orchid Whisperer]

Iowa certainly would include limestone, and shale, and glacial deposits, and is at least west of the Mississippi. That would account for the TDS. I have read that 200 ppm TDS is the high end for regular use on many orchids (and lower is much better). Sensitive genera (I would consider Paphs and Phrags sensitive) certainly require lower.

Ray's company, Firstrays, offers some RO options that you should check out. I've no idea how the cost/gallon for Firstray's systems compare to the $0.39/gal you pay in the store for RO water (Ray probably knows).

A rain barrel is certainly possible in eastern Iowa if you live in a house, assuming that is OK with you and your family, etc.

[Ray]

Originally Posted by smokinjoe1952

1. Ray - If I would get your low end model, I assume it has a CTA membrane, and that, as you say, the (chlorinated) water residing in the unit would prevent serious biological blooms and the membrane from drying out.



Would that be accurate?

Sorry, I forgot what pots you used.

First, let me say that the counter-top system is not "low end" in terms of quality; it's just portable.

No residential system uses CTA membranes and longer, they're all TFC. Water entering the membrane has already been through a sediment filter and a carbon filter intended specifically to remove chlorine and organic compounds. Pure water sitting in a dark, sealed compartment is not likely to develop any growth.

[smokinjoe1952]

Maybe I have a problem using tap water for the flush, and maybe I don't. But, I decided to play it safe and get Ray's least expensive, portable RO system and use it about once a month to fill two 5 gallon water jugs. (Coleman has a nice one)

I'll use this for both regular watering, and for a monthly flush. I don't think I will add fertilizer to the flush water since I use the 2 pot system that completely flushes. (no built-in reservoir)

So now...on to the next orchid crisis!

Thanks to all for the good feedback.

SJ

[Leafmite]

It really doesn't matter what you use to flush as long as you flush very well. The entire point in flushing is to get rid of all the old fertilizer and minerals that your orchid hasn't used. I have flushed plants with my softened water in an emergency (when plants had a bad reaction to a new fertilizer). Most plants can handle a little bad water without ill effects. There are exceptions: Some Pleuros (Masdies, Draculas, etc.) and Phrags can be sensitive to water quality. I have a few non-orchids, too, that are very sensitive, too.

[smokinjoe1952]

It will be nice not buying and carrying in gallon jugs of distilled water from the grocery store. Even nicer not carrying 5 gallon jugs for flushing pots.

(That's how I convinced myself to order an RO system.) :-)

[Leafmite]

If you have a sensitive orchid/plant, just finish the flushing with a dose of distilled water. I have done that when my Butterwort or other sensitive plants accidentally gets watered by the watering can when I have added fertilizer. I flush it well under my tap, then water with distilled water.

Distilled water costs add up and the jugs are rather heavy. I have not only orchids but many other plants and a few, i.e. Cinnamon, cacao (chocolate tree) and Cardamon, are very thirsty and do not fare well with my tap water. I try to collect rainwater when I have the time to help matters. For those who have good water, they will never quite understand....

[estación seca]

You can often buy reverse osmosis water at an aquarium store for much less than spring or distilled water at a grocery store. BYOB.

[Leafmite]

Can you use reverse osmosis water longterm with Lepanthes (and other Pleuros), Butterworts, Venus Flytraps, sarcs, Elettaria cardamommum and Theobroma cacoa? I have been told to use only rain or distilled water with these by those who collect these types of plants. No one ever mentioned that it was okay to use reverse osmosis water so I haven't dared to try it. I would love a cheaper option, though.

[estación seca]

I'm pretty sure the problem with gingers and cacao isn't high TDS, but high pH. I've grown all kinds of gingers with metro Phoenix tap water without problems other than some browning of leaf tips. Same with cacao, which can't be grown here due to heat, not due to our water. And be sure you have real cardamom - the plant Logees sold for years as cardamom is not; it is an Alpinia species, whose foliage smells like cardamom but whose flowers are completely different.

I can't answer to the others. Maybe you can take a sample of your water to a place that can test it for you.

[Ray]

Originally Posted by Leafmite

Can you use reverse osmosis water longterm with Lepanthes (and other Pleuros), Butterworts, Venus Flytraps, sarcs, Elettaria cardamommum and Theobroma cacoa? I have been told to use only rain or distilled water with these by those who collect these types of plants. No one ever mentioned that it was okay to use reverse osmosis water so I haven't dared to try it. I would love a cheaper option, though.

RO water is perfect for such plants. It's about as close to rainwater as you can get for the price. Distilled will be the purest, deionized next, with RO third, and depending upon how urban your environment, all can be purer than rainwater.

Folks don't seem to understand the economies of owning a system. Sure, there's the purchase price to get over, and there are maintenance costs (replacement of filters and membranes), but over the long haul self-produced RO water can be only pennies a gallon.