pH keeps fluctuating

[Surfer Joe]

I am doing a bubble bucket grow and I keep a bucket with tap water and one with extra nute solution ready to add to the buckets as the liquid levels drop.
I keep an aquarium heater and an airstone running in the extra water so that when I add it to the buckets, it will be at a similar temp and have some oxygen in it already.
My local tap water has a pH of 7.4 and a ppm of 295, but after it sits in the water bucket for a couple of days with just the airstone and the heater, the pH goes up to about 8.4.

Why is the pH of the plain water going up?

The pH in the plant buckets drifts in a normal way.

I remember from science that sometimes running air through a liquid can cause some chemicals to precipitate (like calcium carbonate). Could this be causing the pH to go up?
Should I just let the water sit without air or heat before I use it?
I thought that letting the water sit for a few days would help reduce any chlorine, etc. rather than using it fresh from the tap and just adding pH down before using it.
How do you guys manage the adding of extra water or nutes to your bubble buckets between rez changes?

I hope that this grow works because I am amazed at the difference in size between the soil grown plant and the hydro grown plant. The hydro plant is about 3 times larger and it's only on its 4th week since sprouting.
Thanks for any advice.

 

[Hushpuppy]

That is actually quite normal for the pH to rise when adding aeration. I honestly don't know why it does it but I suspect that it has to do with the dissolving of oxygen, nitrogen, hydrogen, and other elements in the air into the water. I wouldn't worry about it, just adjust it before adding to the buckets for use. I would continue to aerate it and let it sit as that is good for the water. Don't worry about drifting pH as that is actually good for the plants, IMO. I set my pH at one spot and let it drift across the sweet spot before adjusting it back every 3 days and the plants love it.

 

[robertr]

That was a good question and also a good answer. I noticed that the other day while checking ph after bubling my water.

 

[Surfer Joe]

I am also not sure about the process or sequence of adding certain elements to my hydro buckets.
I am using canna aqua nutes at half strength and adding ryzotonic and cannazym when I mix up the nutes, and also adding a little calmag.
But what if I want to add some Pond-zyme to protect or treat a bucket for dark roots? Does that get put into the regular nute mix of added in another way?
If I want to clean the roots in h202, do I add it to the buckets or dip them into another bucket for a short time?
Can you use h202 as a preventative treatment?
I am also not sure what amounts to mix for these things.

 

[trillions of atoms]

Carbon dioxide in water forms carbonic acid lowering ph. Air introduced to a solution of water will drop naturally.


Its probibly the bicarbonates already in the water causing it to rise as a byproduct when the air is introduced.

Try running r/o or distilled water and then dosing the same nutes to it and see if its on point.


If your water is tap I would recommend a filter at least if not an r/o unit.

If the nutrient wont buffer the starting water after dosing...then you need a filter or r/o or try using a hardwater micro nutrient designed w more buffers to combat it.

Bicarbonates are added to city water to level ph.