PH Wert der Erde

So you mean next time I should go ahead and water like today again, 4l with just Cal/Mag & pH at 6.5?

And that will make the pH value rise again?

The EC value is clear to me because of more or less fertilizer.

I hope I can still get this under control!

The thing is, and I’m just giving you my opinion, if you keep giving it pH 6.5 (and on top of that using pH Down to lower it to that number), it’s going to take a long time to bring that 5.09 back up because you keep adding acidity to the medium. That’s why the key for the next watering is to raise the input pH a bit higher to 6.8 or 7.0, but without using pH Down at all (if CalMag leaves it high, leave it like that, it’s great), and if you can add a tablespoon of dolomite on top of the soil before pouring in the 4 liters, you’ll see how the runoff starts reacting and going up much faster.

Bunker Ariel is right. Your pH has simply dropped drastically.

I’d say flush with water containing CalMag and a generously reduced amount of base fertilizer.

I’m dealing with the same thing right now. 2.1 EC
Only for me, it’s the other way around. I water at 6.3 and get 6.8 in the runoff.
Only for the last two watering cycles.

Next time, I’ll flush once with a reduced solution and 2 liters of runoff.

Whether you flush now or not.
She’ll handle it, but I would do a light reset. You don’t want to flush everything out, just correct it. That won’t happen from watering just once either. Make sure the runoff isn’t excessive.

Didn’t your soil already have a pH of 5.8 as a starting point?

Yep, it has.

And I skipped the fertilizer before today’s watering.

There’s the explanation for everything, at least for me: that soil is based on blonde peat (Weißtorf), which comes from the factory with a super low pH of 5.8 and is acidic by nature, so as the plant feeds and you flush the pot, the substrate tends to drop on its own towards those values, and on top of that, using an organic bloom fertilizer (Blütendünger) acidifies the mix even further; that’s why I insist you don’t flush the roots because you’ll acidify the peat even more, but rather add dolomite to curb the natural acidity of the peat and start raising the input pH to 6.8 - 7.0 from now on to counteract that very acidic base.

How do I know what kind of dolomite and where from?

BunkerAriel, then I’ll also correct my statement regarding the reset. Didn’t know that it was organic.

Dolomite is super easy to get as dolomite flour or dolomitic lime at any nursery, growshop, or garden center (even in online stores searching for “Dolomitkalk” or “Dolomite lime”); make sure it’s in a fine powder or micro-milled format and not in large granules so that it acts quickly, simply asking for it as agricultural calcium and magnesium carbonate. It’s super affordable, natural, and works great for applying a tablespoon to the substrate now and saving the rest to make your next mixes.

Ok thanks for now BunkerAriel​

That’s true, and a big bag. It’ll last a lifetime.

See above

Aha ok thx

But a question, take a look at my soil a bit further up. Isn’t everything already in there since it’s an all-in-mix? Or should I get extra just to be safe?

“All-mix” is not a protected term.
Anyone can put whatever they want in there.
And you’re supposed to buy the CalMg too

So, I would follow @BunkerAriel’s lead on that.

Dolomite lime is an all-rounder.

If it’s too acidic, it buffers it up until, after a certain degree of acidity, pH level, the reaction automatically subsides, because

calcium and magnesium carbonate react with acid, so once the environment is in an acceptable range, the activity decreases.

I mix it in at every opportunity, right into the soil before the grow.

But sprinkling it on top, working it in, and watering it in—without drain at first—I think works well too.

Cheers

Edit:
Just checked the manufacturer’s website. It doesn’t say anything about it already being limed. A combination of highly potent slow-release fertilizers is supposed to be in there, though. You’re supposed to feed as needed. But I actually understand it as having been invented as a living soil experiment.

That wouldn’t have been my personal first choice. But it is what it is now.

Dolomite

Unfortunately, I’m not familiar with that

I checked the water values for my region and add everything unmeasured and without adjustments, apart from letting it sit before watering (min. 24h) to reach room temperature and off-gas a bit if anything is present, pouring it in, or into the tray from below.

The lime and lactic acid bacteria regulate that in a mutual back-and-forth

Hope someone else can help you adequately with that, but with the dolomite, you’re already well set up.

Ok thanks, then I know for now.

You should not be targeting 6.5 because it is not soil. You are using something that is mainly coco meaning you should be feeding and watering at 5.8.

Ok Thx Crackadoo

For the next grow. I’ll use this soil. Looks good. Green Home

Hi

I started with a clone. Just a bit careful at first. You can skip veg fertilizer, the soil is pre-fertilized enough. You only need to start using bloom fertilizer around week 6-7 when the flowering phase begins. Before that, just Cal/Mag and keep the pH around 6.3 (6.0-6.5).

Magic

These are the fertilizers. Although with the soil, you only need the bloom fertilizer.