Seaweeds may drastically lower PH to dangerous levels?

[DavTom]

Originally Posted by Ray

Most of my collection is paphs and phrags - they get a monthly Kelpak treatment all year.

I will be potting up some deflasked paph seedlings tomorrow. They are currently submerged in a Kelpak + probiotic bath overnight.

Pardon me Ray as probably you have already responded to the same question here or on your website.

Do you apply Kelpak, Quantum and K-lite in the same watering solution, or you prefer to keep Kelpak and Quantum separated?

Thx.

Dav

[Ray]

Originally Posted by DavTom

Pardon me Ray as probably you have already responded to the same question here or on your website.

Do you apply Kelpak, Quantum and K-lite in the same watering solution, or you prefer to keep Kelpak and Quantum separated?

Thx.

Dav

When I still had my greenhouse, K-Lite was automatically metered into my RO water, so I put Kelpak in a hose-end sprayer the first watering of a calendar month, applying both at once, then the second watering of a month, I did the same with the probiotic.

However, I did that only for convenience, as the hose-end sprayer only held enough Kelpak for 64 gallons of solution, or 32 gallons of probiotics.

Now that I have a much smaller collection, and that sprayer has sufficient capacity to water the whole collection while they’re out on my deck in the summer, I feed weekly using only K-Lite, and apply the two supplements together a week later. In winter, when they’re indoors, I water using a 4-gallon, battery-powered sprayer, and I mix all three together one week a month, followed by weekly, fertilizer-only treatments.

Here’s the bottom line - they are synergistic. Sure, we focus on the three components being beneficial to the plant, but the nitrogen in the fertilizer also stimulates growth and reproduction in the microbes, and the Kelpak ingredients feed them as well (kelp extracts are part of the feed stock when producing the products in the first place). By using all three together - or as close to that as you can conveniently do so - you are maximizing their overall benefits.

[K-Sci]

Originally Posted by estación seca

Under my conditions plants in S/H with monthly Kelpmax/Kelpak grow better than plants in other media.

ES, how do you dose KelpMax in S/H monthly? My intuition, which is certainly not 100% reliable, is that if Kelpmax is in the S/H water, it would be like watering with Kelpmax at every watering. That is, unless you replace the water after a day or so.

-Keith

[Ray]

Originally Posted by K-Sci

ES, how do you dose KelpMax in S/H monthly? My intuition, which is certainly not 100% reliable, is that if Kelpmax is in the S/H water, it would be like watering with Kelpmax at every watering. That is, unless you replace the water after a day or so.

-Keith

Certainly, in S/H, the plant would be exposed to the product longer than if applied to a potful of bark, but if you only apply it once a month, it isn’t anything like using it at every watering. The ingredients are absorbed relatively quickly, those that aren’t decompose, and the next time you water, you’ll be flushing the pot anyway (assuming you’re watering a semi-hydro pot correctly).

[K-Sci]

Originally Posted by Ray

Certainly, in S/H, the plant would be exposed to the product longer than if applied to a potful of bark, but if you only apply it once a month, it isn’t anything like using it at every watering. The ingredients are absorbed relatively quickly, those that aren’t decompose, and the next time you water, you’ll be flushing the pot anyway (assuming you’re watering a semi-hydro pot correctly).

Thanks Ray!
I have two seedlings in S/H as an experiment. I water them the same as the non-S/H except that the pots are sitting in trays of water.

-Keith

[estación seca]

You live in Germany; I live much farther south. Some of my plants can grow all year.

[Ray]

I guess what I'm getting at is that pH is a measure of free H+ ions compared to OH- ions. pH tells us the relative measure, but not the concentration.

I'll use a ridiculous scenario to make a point:

Solution 1 - contains 10 H+ and 1 OH-
Solution 2 - contains 10000 H+ and 1000 OH-

Both have the same ratio of H+ to OH-, so have the same pH, but Solution 2 is a much stronger acid than Solution 1.

If solution 1 was poured on the plants, it would very soon be overwhelmed by the plant/medium/microbes. Solution 2 might kill it.

Citric acid is often added to fertilizers to enhance solubility, especially if they contain calcium, and the resulting solution pH is fairly low. Citric acid, however, is such a weak acid, that its acidity is "squashed" by almost any addition.

[DavTom]

Originally Posted by Ray

I'll use a ridiculous scenario to make a point:

Solution 1 - contains 10 H+ and 1 OH-
Solution 2 - contains 10000 H+ and 1000 OH-

Both have the same ratio of H+ to OH-, so have the same pH, but Solution 2 is a much stronger acid than Solution 1.

If solution 1 was poured on the plants, it would very soon be overwhelmed by the plant/medium/microbes. Solution 2 might kill it.

Thanks for pointing that out, I agree with that.

But how can you be sure that the solution you may have in the reservoir is like Solution 1 and not like (or closer to) Solution 2, unless you have done extra tests (like mine below) to check it?

If it was a very soft (i.e., very low TDS) solution, in which you know that your are not adding any significant amount of H3O+, then I would agree with you.

But look at my case: I have added a very small amount of Seaweed solution (just at 1/7 of recommended dose) in 5L watering solution and the PH dropped by 1.5 units. This does not tell me yet about the concentration of H3O+, but just the ratio between H3O+ and the OH-. Fair enough. That's why I wanted to see how much of my tap water (which is very alkaline with a PH of 8.4 - it has 10KH German degrees) I needed to add to neutralize that drop of PH. Well, as I wrote in my previous post it took me 1.5 L (or even 2L I do no remember it now by hard, but it is in the post) to neutralize the PH drop. This means that that small amount of seaweed added a dangerous amount of H3O+.

If I were you, if you did not do it yet, I would make a simple test like mine to make sure you are far enough from Solution 2 scenario.

Dav

[Ray]

Originally Posted by DavTom

If I were you, if you did not do it yet, I would make a simple test like mine to make sure you are far enough from Solution 2 scenario.

Dav

Davide - I did that testing a good 15 years ago or more. I have not bothered adjusting my solutions since, and I have experienced no issues.

That said, I basically only use 3 products on them, so that's been a constant.

[DavTom]

Originally Posted by Ray

Davide - I did that testing a good 15 years ago or more. I have not bothered adjusting my solutions since, and I have experienced no issues.

That said, I basically only use 3 products on them, so that's been a constant.

OK, Ray. Sorry I could have stopped this conversation earlier, but this did not come clear to me from your previous posts. I wrongly thought you had checked only the PH and not also the H3O+ concentration.

One last point still related to PH. What do you think about low PH and micronutrients toxicity? Some microelements (in particular iron and manganese) become drastically more available for plants uptake at lower PH and this may easily lead to toxicity. Frankly speaking, I do not know if this has a dependency with H3O+ concentration.

What are your thoughts about this? Did you do any tests, or you simply assumed there is no problem because your plants are doing fine since a long time?

Dav