info on ph water

[MikeD2003]

tap water comes out at 7.4 to 7.6 ph i ph down to 6.5 3 or 4 days later ck. ph it be up 6.9 and higher from just setting in closed container

[kingfish]

What's your point Mike ?

[9fingerleafs]

yes thats an issue cause you want it to stay in the 6-7 range, do you know the EC/ppm of your tap water? have you tried using RO water?

[Siri]

If I understood you correctly Mike; you adjusted the pH of your water, kept the water in a closed container and now the pH has changed. Thing is, (as far as I know) you should only prepare as much water as you need and then use it right away. Water should never sit stagnant like that, it’ll cause you all kinds of problems.

[PuravidaC]

What other problems? I use tap water and let it sit in an open one gallon container for days to let all the chlorine dissipate. I adjust ph right before using but what other issues can come from "stagnant" water?

[9fingerleafs]

I think the biggest issue is oxygenation. Hydroponic systems need air stones to resolve this issue. There is some chemistry I don’t really know but CO2 reacts with water to create acidic compounds and oxygen levels go down overtime. I’m sure a couple of days it’s not going to change much. But failing to oxygenate big water reservoirs could impact the plants

[Flockshot]

Yes, the PH will change just from sitting around. It will also change with the amount of oxygen, and temperature of the water. Many things can impact PH in your water, and I don't claim to understand them all.

PH is not an exact science, and is always changing. All you can do, is get it where you want it, and use it.

[Weed Pharma]

Your issue is likely one of total alkalinity (TA) - the carbonate and bicarbonate in the water and its capacity to neutralize water, which effects pH stability and drift ( assuming no nutrients are in the water).
I personally don't deal with it in grows, as I mix - adjust pH and use it, as Siri suggests.
I have experience with TA from hot tub water conditioning.

[PuravidaC]

I have ph drift in my hot tub too! 😁 But as far as growing goes, I adjust ph and use immediately.