Lake water ok to use?

[ccrow]

I'm in northeastern US, where we haven't had much rain; we have a well, and I've just been using lake water for my outside plants in order to spare the well. Is there any reason I shouldn't use the lake water for my orchids?

[Subrosa]

Lake water is about as descriptive a term as the word "dog". You need to run some tests to determine whether it's suitable. Tds (total dissolved solids) would be a good start, as would pH and perhaps KH.

[Orchid Whisperer]

If you have some sort of cooperative extension office (sometimes known as a "county agent"; often an agency affiliated with an agriculture department at a university, or state department of agriculture), they may be able to test the water for you. I would have them test pH and total dissolved solids (TDS), or if it is cheaper, electrical conductivity. TDS will be expressed in units of parts per million (ppm), equivalent to milligrams per liter (mg/L). Electrical conductivity can be expressed in a variety of measurement units, and as long as you know what the units of measurement are, you can estimate TDS from conductivity. Conductivity is easier and possibly cheaper to analyze.

There is nothing that is intrinsically safe (or dangerous) about using lake water, but the testing will help you see if it's OK for your plants.

[estación seca]

If you splash lake water on windows, and when it dries it doesn't leave any white residue, it's probably OK for your orchids. It's better to test it and find out for sure.

[Subrosa]

Originally Posted by estación seca

If you splash lake water on windows, and when it dries it doesn't leave any white residue, it's probably OK for your orchids. It's better to test it and find out for sure.

Hmmmmm......if you're playing it quick and dirty that's actually a pretty good test! It figures you'd know all the benefits of evaporation.........

---------- Post added at 06:39 AM ---------- Previous post was at 06:32 AM ----------

Have you had your well water tested? The critical parameters of well water vary widely as those of surface water.

[PaphMadMan]

For many years one of the large orchid growers outside Chicago used water from a roadside pond in the greenhouse, and they grew fantastic plants. The advise to get the water tested for mineral content is good, no matter what the source, though if the bedrock in your area is mostly granite it probably isn't a problem. For surface water near a highway or urban area in a northern state, salt content might be an issue as well as hardness. Otherwise, if the water quality is good enough to swim in it is probably fine.

[ccrow]

Thanks for the replies! I guess for now I will just continue with the well water. We have had it tested before(although I don't remember the results) but anyway, that's what I've been using all along. I know the lake association does water quality testing, maybe I can find out about it through them.

[Subrosa]

Originally Posted by estación seca

If you splash lake water on windows, and when it dries it doesn't leave any white residue, it's probably OK for your orchids. It's better to test it and find out for sure.

Originally Posted by ccrow

Thanks for the replies! I guess for now I will just continue with the well water. We have had it tested before(although I don't remember the results) but anyway, that's what I've been using all along. I know the lake association does water quality testing, maybe I can find out about it through them.

See if you can get a copy of the results of the lake testing. The information you need is almost certainly going to be there.

[PaphMadMan]

Another thought. Some places would have regulations about removing water from public surface waters. Usually it would only apply to agricultural or commercial use, not small scale private use. If you're dipping buckets out of the lake I doubt any regs would apply, but if you're using a pump in some places it could be an issue.