PH Problems

[grey1223]

Thought I'd share my trials and tribulations with my runoff ph.

Mother Plants: used to not worry about runoff as vegging plants have never exhibited any signs of distress. Until recently, I noticed burnt leaf tips awhile back. Flushed with Clearex and they came right back. That's mostly because she is rootbound. A week later I checked the runoff and it was still 5.8. Since then I've fed and watered with 7.0 and runoff is up to 6.2. So it seems to me that you can veg a plant and not worry so much about PH.

Vegging Plants: After 5 weeks vegging the runoff is 6.1 while input is 6.8. But again, no problems and they look great.

Flowering Plants: Here's where they go whacko. After 7 to 10 days in 12/12 new growth start showing burnt leaftips. And then within another couple weeks I see mg. def. that looks like lockout. The runoff ph was 5.8. Soooo, I've been giving them 7.0 solution and got it up to 6.0. So Monday night I got impatient and fed with 8.0 water. Runoff came up to 6.4. Plants did not react to 8.0ph solution I gave them. Thankfully, as I was scared to death to give the girls solution that high.

I'm using PROMIX HP. From what I'm seeing it would appear that this brand of medium needs more buffeting. OR- perhaps us hand waterers should be feeding with a more alkaline solution. I see two solutions and would like any feedback from others that have dealt with this problem.

1. Add dolomite lime to promix before using(supposed to have some in it). or

2. Feed and water with 7.0 or higher.

What do you think?

[Mr. Clandestine]

I almost always add dolomite lime to my soil, since at least 1/4th of it generally consists of peat. And since it gets added every time I need to transplant, I rarely run into troubles with runoff pH dropping too low because of depleted lime. If you do less than two transplants over the course of the plants life, you may either need to add more to the soil, or go with the second plan of attack.

Testing and correcting water EVERY time you need to feed seems a little tedious to me, which is why I prefer the lime. But, to each his own.

Take care. :jointsmile:

[stinkyattic]

I am using the ProMix BX lately because the farmer supply doesn't stock the right compost over the winter. I notice also that in veg, the plants appear more tolerant of wacky pH but in flower, they will show problems more readily. I've started adding CalMag to my watering solution after running an alkalinity profile on my well water and discovering that while it took an unheard-of amount of H2SO4 to drop it to the test range (pH 4.5), the actual alkalinity as measured in mg/L of CaCO3 was only 2.4! :eek: meaning I'm running a shitload of orgnic acids- probably tannic considering it's a hemlock forest- through the ProMix. What all this means is that my lime is getting used up super duper fast and I'm supplementing the buffer in the soil with the buffering ability of the CalMag.
Just a little rambling... I'm running on like 4 hours of sleep... :drool:

[saltypimp]

so... if i add the "1 tablespoon" per gallon, such as I have read... what ph should i mix my 100% organics at ( i mix 24 hours ahead to stabalize ph)...

Ive been told 6.3-6.8 with organics, and witrh hydropnoc nutes 5.8-6.2

Again, if i add the 1 tablespoon per gallon, what PH should i mix my nute solution and water to??? And what ph runoff am i tro expect?

thanks guys

[stinkyattic]

I think the term 'organic' in this case- you mean 'soil'? There is organic hydro and the pH is in the range you gave for regular hydro. In soil, 6.4-6.8 is good, in soilless, 6.1-6.5 is more what you are after. Your goal is to get your RUNOFF to the correct pH, so you will have to check it regularly and adjust the nute solution going in, because it interacts with the soil as it goes through, and both pHs change.
Of course, if you re-pot frequently, into a soil or soilless that is at correct pH, you don't have to worry so much.

[saltypimp]

THANKS STINKYATTIC -
so my goal is 6.1-6.5 for the soilless "medium" and adjust the medium from ther nute solution...

Would it hurt to add 1 tablespoon of dolomite lime per gallon (and keep doing it every transplant), or does this seem like to much...

thanks... ive been a nuisance