Can I use distilled water for regular watering? - Orchid Board

lund0682 · #1 02-19-2011, 01:38 AM

My question is about using distilled water to regularly water my orchids. Is this okay, or is it bad for the plants?

I've checked out some other threads and it seems like a lot of people get by just fine with tap water, but I also know that everyone has different tap water - and I don't know anything about how MY tap water measures up. So what I've been doing is just buying a gallon of distilled water at the grocery store once a week and using that to water the orchids. I only have three orchids, so it's not like a huge inconvenience.

Is there any reason I shouldn't do this? So far, the orchids seem fine (two paphs and a phalaenopsis).

quiltergal · #2 02-19-2011, 03:28 AM

Just make sure you feed with a fertilizer that has micro nutrients in addition to the normal N-P-K. The distilling process removes all of those beneficial minerals out of the water so you have to make sure you replace them.

boytjie · #3 02-19-2011, 09:19 AM

I've been using distilled water from the supermarket exclusively for two years, because my tap water isn't that great for more sensitive plants. I ad a teaspoon per gallon of epsom salts once a month - plants seem fine and happy, and they bloom! One of these days I'll get around to installing a RO system...

lund0682 · #4 02-19-2011, 11:27 AM

Great! That's exactly what I wanted to know. I'll make sure to fertilize with something that has micronutrients.

I suppose that's basically what the epsom salts do. By adding epsom salts I guess you're just adding things back to the water that the distilling process removed. What exactly do the epsom salts contribute?

Are there other things you ever add to the water?

And thanks for the help! I'm still a total rookie at this.

camille1585 · #5 02-19-2011, 11:48 AM

Epsom salts add magnesium, so it's not ideal as the only additive to distilled water. You need to get some calcium back into it, among other things To put the maximum of trace elements back into the water you would probably need to use a fertilizer meant for pure water. I think that there are also issues with pH if 'normal' fertilizer is used in pure water (rain, distilled, RO), since the water has nothing to buffer the pH with. But don't take my work on that, I'm not a chemist!

boytjie · #6 02-19-2011, 11:50 AM

Epsom salts are for magnesium. Since you're using distilled water, you could also get some MSU fertilizer geared specifically for RO (reverse osmosis, or pure) water. Try to get a couple of different kinds, and alternate between them - one might contain different nutrients that might not be found in the other. And be really careful not to over-fertilize! I dilute to half of what the container says, and feed once a week. (The tried and true advice for fertilizing is "weakly, weekly.") For sensitive plants like Masdevallias and other Pleurothallids, I'll go down to 1/4 of the recommended dose. Less is always better. I hope some other folks here will chime in with their recommendations as well.

DavidCampen · #7 02-19-2011, 01:46 PM

I use Dyna-gro Orchid-Pro as the fertilizer for use with RO water; it has calcium, magnesium, iron and other micronutrients.

Orchid126 · #8 02-19-2011, 04:16 PM

You can also use purified water (r/o or reverse osmosis), which is almost as pure as distilled water, and a bit cheaper. Or you can use spring water which is cheapest of all. And you can also use half tap and half purified, in which case you can use regular fertilizer because tap water contains the calcium missing in r/o or distilled. Check your water bill, there should be a phone number to call and you can get a free analysis of your water.

Dyna-Gro is another good fertilizer with micronutrients. It was developed for hydroponics.

lund0682 · #9 02-19-2011, 04:40 PM

Thanks again for all the great suggestions!

I didn't know I could get a free analysis from the water company - that's great! I'm guessing that if my tap water is basically okay, then the only potential problem would be with chlorine? Is there anything else in the tap water I should be on the look out for?

But I suppose there must be other threads on water chemistry that that I could look into. Still, I'd be glad for any quick comments anyone has on the subject.

camille1585 · #10 02-19-2011, 04:49 PM

If chlorine is the only issue with the water, then that's easily solved by drawing water the evening before and leaving it in open containers for the water to evaporate.

Orchid126- Spring water is not pure water. It will carry more or less minerals depending on the rocks layers that it goes through, but it's composition will be closer to tap water than to distilled water.