Lake water for orchids?

[KristenReuel]

I'm moving from a city with great tap water (I just had to leave it out for 24 hours to get rid of the chlorine) to a city with extremely hard water.

Now, my family has a cottage on an extremely clean lake in the Muskokas in Ontario. It is a spring-fed lake. Would there be any harm or benefit to taking a few jugs and using it for my orchids? Would it be similar to rain water?

[Dante1709]

I would be concerned for any bacteria/viruses/algae in the water. Also, pesticide and fertilizer run-off is possible with lake water. If you have a TDS meter, use it and see how pure the water is. If not, collecting rainwater seems like a better idea.

If the water isn't bad (I.e. clear) you can always heat it up and strain it to get rid of anything harmful. I do this when my rainwater gets algae and leaf litter.

[Orchid Whisperer]

Kristen:

Lake water for your orchids should not be a problem. Looking up that area on Google Maps, it appears the lakes are pretty much surrounded by trees; it is unlikely you would get much agricultural runoff. If you get a little, the fertilizer content would likely be low, and not a problem. I also think that bacterial and viral risks would be low (there will be bacteria, but probably not the kind that causes problems for orchids; same goes for viruses). You do not need to boil water that you are putting on your plants.

A water quality report for regional lakes can be found here: https://muskoka.civicweb.net/Documen....aspx?ID=22919 The water quality I see is very good. It should be fine to use this water as-is. If you get a lot of particulates in the water (bits of leaves, sand, etc.) you can just filter it through a paper towel if you like (but it is probably not necessary).

[james mickelso]

Lake water can be very hard too. It depends on what geologic province in which the lake resides. If it is in a region where there is a lot of iron or limestone, that would be hard water. If it is a region where there is a lot of granite, then it would be ok. pH is also a concern. Call the local water purveyor and they can give you this info.

[Orchid Whisperer]

James:

You are quite right, hardness depends on the underlying geology. Much of that part of southern Ontario is felsic plutonic rock and migmatite (using less geeky geology terms, think granite), so soft water is expected. Also, have a look at the water reports at the link I provided. The reports don't present hardness directly, but the Ca is pretty low for most of the lakes that are listed. Also, alkalinity is either very low or low-moderate (nothing over 60, I think). Yes, alkalinity is not the same as hardness, but the low buffering capacity suggests that hardness should also be pretty low.

[ALToronto]

Muskoka is on granite, so the water is soft and likely acidic. The town or township that has jurisdiction over your lake does regular water testing. I would be concerned about algae, bacteria, fungi and gasoline.

[tropterrarium]

I would also look at pH, due to surrounding trees (humid acid). I would not assume anything about the water, just check it out on a monthly basis. May save you a lot of trouble down the road.

[KristenReuel]

Thank you everyone! I have one last pH test strip, I shall use it on the lake water.

I think I'm going to start using it on my less expensive orchids to start off (If it passes the pH test).

Thank you for all of your research, Orchid Whisperer! The lakes are indeed surrounded by wilderness.