Buffered coco

[Gingerbeard]

I had to get a different brand of coco than last time: Cloud Coco. The bag says it's buffered. No idea what that means. My plants are showing signs of pH problems. No pictures. You know what pH problems look like.
In my haste to get out of the 1-gallon pots and into the 5, I only wetted the coco. No flush. pH in is 5.8 after 15 minutes of aeration, adding pH down after aeration. pH out, an hour after nute-ing is still 5.8. Prescribed Cal-mag and 80%ish regular nutes.
Do I need to do a pH flush?

[Rik]

If you’re having pH problems, maybe try Nebula’s suggestion and correct your pH before aeration, not after.

[Gingerbeard]

Well dang, heck. You're the second person to say that. It's what I've done in the past with no pH issues.
Guess I'm going to have to listen to the higher authorities.

[Ckbrew]

Coco has the ability to bind Ca+ and Mg+ ions, therefore making them unavailable to plants. Buffering in this case is soaking the coco in ph water and calmag at a high concentration, for the purpose of saturating the binding sites. Once the sites are used up, the Ca+ and Mg+ are available for plants to use. Ph and Ca+ problems often occur together. If you flushed with ph water and high calmag, I would think that would steer you in the right direction.

As far as the aeration issue goes, I mix my solutions with fresh tap water (well water, no chlorine) which goes through an aerator, so I am kind of stuck there unless I want to take the faucet apart. Have not had issues because of it.

[Gingerbeard]

My water sits to off-gas chlorine so doesn't stay O2'd. It's just a thing I do.
10-4 on the flush, Ckbrew . I have to remention that the coco is supposed to be buffered. So I shouldn't have to worry about CaMg not being available?
Something interesting is seeing how the pH thing is affecting my different strains. GDP is not enjoying the treatment.

[Ckbrew]

I have to remention that the coco is supposed to be buffered. So I shouldn't have to worry about CaMg not being available?

If they did what they said they did, then no. If they didn't, then you might have a potential problem. An extra dose of calmag won't hurt the plant, and would help avoid a problem before it starts is my thinking. Sometimes different strains have different solution needs.

[Mr.furley]

The answer to your problem is in your own question.

1) Buffered Coco is usually washed with 6.3 pH'ed water and sometimes will include additives like calcium/magnesium but mostly mycorrhiza depending on brand.

2) Aerated water will usually read Point .1 to .2 higher then resting water, your are at 5.6 to 5.7. Best practice would be to aerate for 24 hours then rest for a few hours, nute, Ph, use. There is Merit for oxygenated water depending on how much snake-oil you'd like to buy.

3) Most importantly Cal/Mag is not absorbed in Hydroponic/soiless no matter how much you throw at it unless you run your pH higher than 6.2, That is your ph problem.
Manganese is the only thing you miss by running 6.2 and IMO is strain-specific in most cases For defficiencies.

"Cation Exchange" is the brain bending rabbithole you probably won't Google.


You run coco 50/50 perlite on the mix as it reads in your signature?

[Gingerbeard]

Thanks Mr. F.
Yes. 50/50 blend. It's what I could get. Honestly, it doesn't look any different than 70/30.

[PuravidaC]

I rarely make comments as there are many here with better understanding of growing X's and O's. However, when I switched to coco I started having issues that sounds like yours, dark brown spots and yellowing, crispy leaves all over. Starts small but spreads through entire plant. It haunted me for several grows until I finally figured out that my tap water was pretty hard and didn't need added cal-mag. I buffer coco with cal-mag to start but that's all I use throughout grow. If you can find a photo of cal-mag toxicity it may match yours. Seems to be a rare problem but it sure worked for me.