Do you adjust pH when watering?

[newflasker]

I check my tap water and found out that it's pH is too high, around 8.2. pH could make a lot of different in growing plants especially orchids. In vitro, orchid seedlings are growing with pH around 5.4 - 5.8. So I adjust pH of my water to 5.8 a month ago and found out that my Phal. and Den love it. Each of them gives me 2-4 new roots and spike. May be I am a day dreamer. I am not sure this is the season for them to have new root and spike or adjust pH of water does it. Anybody adjust pH when watering? Please share your opinion.

[Ray]

I use the GreenCare MSU RO fertilizer and in pure water, it gives me a pH in the range yours is with no adjustments needed.

When I used Dyna-Gro "Grow" in RO, the pH was so acidic I had to raise it to that range with Pro-Tekt.

[camille1585]

In Lyon the pH of the tapwater is a little bit above 8, so I bring water back from my country house to water the orchids with. Most of the village's water comes from springs, and the pH is generally around 6-6.5. And I think it DOES have an effect on the plants! A plant's maximum absorption of trace elements is with a pH between 5,5 and 7. So with a pH of 8, trace elements such as copper, bore, iron, zinc and manganese will be poorly absorbed, even if they are present in your fertilizer. The plants probably don't have a deficiency, but probably aren't getting as much as they could. But I don't know if adjusting the pH will suddenly make your plants put out new growths like that so quickly!

[Des]

Ph is very important , I grow cymbidiums and they prefer a ph of 5.5 to 6.5 any higher or lower and they struggle to take up essential nutrients one of them being iron. I also find that tap water has very little dissolved oxygen in it so I aerate my water with an aquarium aerator this in itself has made a marked difference in the health of all genera in my collection Also watch the electrical conductivity (ec) many orchids can't handle much in the way of salts

[Ray]

I may be incorrect here, but I think that we are traveling under a misconception. Yes, pH is an important parameter, but I don't think it effects the plants' ability to take up nutrients. What the pH controls is the water solubility of the mineral elements, making them available (or not) for absorption.

In the 5.5- to 6.5 range, pretty much all of the essential nutrient minerals are soluble and readily available to the plant. If you go too far out of that range some precipitate out, while others are still in solution, and that can lead to toxicity.

[Des]

Thanks for that Ray , I think you are right, makes a lot of sense to me , and it is quite possibly why manufactures of some insecticides recommend that the water used to dilute is within this ph range . Makes one wonder though why the Disa which grows in the peat bogs of Table Mountain needs a ph of 4.5

[orchids3]

I believe a pH of 5.8 to 6.2 is optimal for all the nutrients to be available to the plant but water isnt the only consideration. Media breakdown also affects the pH
the roots see. Check the pH of the media as well. In the past I soaked a test plant in a container of water then lifted the pot out letting the water drain out of the pot into a containter. The pH of the drainoff water is the one I adjusted my pH too. I recently bought a soil test probe and am trying that as well but know I must steralize any probe before I insert it into a pot. The pH of the wet media gives a good indication of the health of the media as well. Too acid,with properly adjusted water and/or fertilizer solutions, indicates boken down growing media.

[gixrj18]

I PH all of my nutrients and supplements (anything that involves nutrients). However, if I'm just giving them a good flush of water, I'll just use tap or reverse osmosis water. Most fungicides, algaecides, etc. should also be adjusted.

[Ray]

With PrimeAgra as a medium in semi-hydro culture, your nutrient solution pH is all the plant sees, so it's much simpler.

As the the disa question (and it applies to other semi-terrestrials, as well), you have to consider the local geology, as that's what controls what elements are in solution, and in what concentrations.

[IdahoOrchid]

What would one use to measure the PH fairly accurately?