Unstable pH

For years I’ve used food grade citric acid to lower pH as my water source approaches 9.0. After some reading and testing I see that this is unstable - within hours of dropping it to 6.5 or so it goes right back to 9.0.

I can inagine that such a short stability window causes problems even if poured onto the plants (I grow in soil) immediately but that’s probably a complicated discussion. Are other approaches, liquid ph down, more stable and if so, which ones?

Phosphoric acid is often used in commercial PH down products, it works well.

You've been growing for years, how are your results?

If you've been using citric acid, and it's been working, do you really need to change anything?

I'm also using phosphoric acid.
If I have anything left in my water tank I usually check ph again before using it and adjust it again.
I haven't checked it after only a few hours, so I couldn't really tell you how long it takes before it goes up again, but it does.

I tried citric acid for a bit, for me, it was ineffective.

General Hydroponics pH Down (the orange one).

I'm a firm believer in pH'ing everything. I grow in inert potting mix. I try to get the runoff to be the same as the input. I know that people often confuse "soil" and "dirt" and "potting mix" to all mean the same thing and work the same way. That's not true. If you pick up a scoop of outdoor, garden "dirt", then you'll see all kinds of critters and things working in it. But, when you look at a handful of Fox Farm Ocean Forest, the only thing that you MIGHT see in it is some fungus gnats. Other than that, it's not "living soil" no matter how many Mykos you add. It's never going to kick "on". That's why IF you grow in bagged "soil" then you need to be aware that there isn't anything living in it that will regulate the soil pH in the way that actual "dirt" will do.

Thanks all. I’d “like” you’re replies but it i don’t see the option. Anyway I use ocean forest too, and as for success, I’ve done well with new plants and clones from mothers I’ve raised. It’s just the germination part I struggle with. Off to buy a new type of ph down

Soil Growth said:

... If you've been using citric acid, and it's been working, do you really need to change anything? ...

Click to expand...

I switched to 85% phosphoric acid to reduce the quantity of pH solution needed. From a minimum of 1/3 cup of vinegar in 4L to 35 - 40 drops in 8L

Bon Farling said:

... It’s just the germination part I struggle with ...

Click to expand...

Please do tell ... what goes wrong when you try popping some beans?