What levels of Sodium and Chloride are "safe" for orchids??

[orchids3]

My water tests show 17 ppm of sodium and 25 ppm of Clorine. I also know that the quality of my water is something some people would kill for. No one mentioned that a lot of water softeners add NaCl to the water at fairly high concentrations. Hope you are not using softened water. ?

[malathi]

hello, i have a strange problem/ question. my orchid plants were recently infested with tiny snails, and these critters destroyed the tender roots and new shoots of almost all...i was devastated.... i tried all possible measures including pesticides and apple slices and stale beer... none worked...its too difficult to pick each one of these physically from the 75 odd plants i have! I tried spraying common salt powder and the snails just frothed and died immediately.... my question is, will it hurt my plants to have NACl exposure in this form sprinkled at the top of the media? pl help or suggest alternatives

[Orchid Whisperer]

Hi nhman

As a rule of thumb, total dissolved solids (TDS) should not exceed 200 mg/L for orchids. With the chloride and sodium levels you have, you are going to exceed the 200 mg/L limit.

You can't remove the chloride by evaporating it; that will just concentrate sodium chloride in your water (this is how salt pans work in regions where salt is produced by evaporating sea water).

You can use a reverse osmosis system to reduce dissolved solids, or you can capture and store rain water and use that. As orchids3 mentioned, if you have a water softener, be sure you are taking water for testing, and for orchids, before the water softener.

[Ray]

Originally Posted by Orchid Whisperer

Hi nhman



As a rule of thumb, total dissolved solids (TDS) should not exceed 200 mg/L for orchids. With the chloride and sodium levels you have, you are going to exceed the 200 mg/L limit.

May I ask where those numbers come from? I fear there may be a context factor we're missing.

In nature, most orchids will never see over 25 ppm TDS, usually less. On the other end of the spectrum is our application of fertilizer, which for example, at the 125 ppm N concentration used weekly by the folks at MSU when testing that fertilizer, equates to as much as 900 ppm TDS, resulting in good plants, not damage.

[Orchid Whisperer]

Ray, the TDS 200 ppm "rule of thumb" number came from an information sheet from Houston Orchid Society "Water Quality and Orchids" authored by Calvin Starr, ca. 2007.

I wish I had an active link to it, but I don't. I saved it as a PDF, might be able to send it to you when I get home if you are interested.

My reason for citing it here is to indicate the OP was at the limit & needed to seek out a solution to obtain better quality water. EDIT: e.g., the context is the quality of WATER only, rather than water + additives, if that helps.

[Ray]

OK, so that - I assume - was meant for the water itself. I though I may have misinterpreted that.

Thanks.