Questioning the need to adjust nutrient ph in soil grows with dolomite

[sproutco]

I ended up mixing equal parts FFOF and PromixBX, about 30 gallons, to which I added 2.5 cups of d. lime and more perlite.

Your going to end up with too high a ph because promix for sure has lime already and i bet ffof is limed.

 

[vonforne]

Your going to end up with too high a ph because promix for sure has lime already and i bet ffof is limed.

ya sproutco it is, they use oyster shells for their ph adjuster. 6.3 to 6.8 is what their product description states on their web site. I just add less d lime. 1 instead of 2 tbls. but I also add more peat and 16 litre of worm castings plus admendments. So at final transplant I would still add the d lime to keep the ph at 7. What the FFOF has in it will not maintain the ph drop during flowering if you add acidic materials to their mix. and every one seems to be having their problems then with the ph.

I have some activated FFOF waiting for transplant with no extra lime in it. I will take a test today and post it to night. I have added pure peat and castings to it and want to see what the ph is holding at right now before the d lime is added.

 

[stretchpuppy]

Your going to end up with too high a ph because promix for sure has lime already and i bet ffof is limed.

I went through two grows using Promix, ended up with negative results from lack of lime (Cal, Mag, Ph flux, etc), and I question the amount of lime promix even contains, but I know a little is there. How did your latest couple recent grows go using promix only?

OF uses oyster shells to balance Ph, and contains no mention of lime anywhere on the bag or ingredient list.

Actually, I have a feeling this will be my best harvest yet.

 

[Guest]

I use 2 tbls of dolomite per gallon ocean forest,its definately not too much.I dont trust a little oyster shell to keep my ph stable during flower.

 

[meduser180056]

So you think I should go with 1 or 2 tbsp per gallon of Pro-mix?

Guess I should go look for some powdered dolomite lime since the stuff I got here is in pellets.

Stretchpuppy- I've used pro-mix hp for the entire grow several times my PH does sink to the 5-5.5 range towards the end of flower, but it didn't cause lockout that I could tell. They only yellow after flushing.

I'm gonna add lime next time though cuz I think it's a good idea.

 

[inflorescence]

If oyster shells don't degrade in a NaCl solution (the ocean lol) then how they gonna degrade qucikly enough in peat?

Also, why can't ya just mix some powdered dolo for the inital buffer and some prilled for the long term buffer?
Yes, uneven mix may occur with prilled but since roots adapt to their rhizosphere wouldn't it beneficial to have a high pH pocket to uptake certain micros at that location and a low pH pocket at another root location to uptake the micros not taken up at the high pH pocket?

 

[purrpullkush]

good point inflorescence, ffof doesn't have any lime in it and like pther people have mentioned they are using oyster shells to buffer ph which almost definitely wouldn't be effective in a <3 month cycle.

 

[Guest]

I guess the only way to know for sure is to do it for yourself,using promix without 2 tbls of dolomite is just asking for trouble IMO.I've been using 2 tbls with my ocean forest too and it works fine,no high ph here.Sproutco you are the first person I've ever seen say 2 tbls of dolomite is too much,and 1 1/3 is correct?I'll just stick with a couple tablespoons since its been working for me.