Ph Problems

[Norby]

Is phosphorous supposed to bring the ph of the water down to the low 5's to hi 4's when fertilizing?  I'm having problems with keeping the soil ph in the 6 range.I think it's because I add so much perlite and have to liquid fertilize much more, about every other watering or more.  I add potassium chloride?(natural ph up) to get the ro water to 7.  I think I didn't have a problem before because I was using city water with a hi ph and buffers from the hi limestone contact.  Should I add limestone to my reservoir (not hydro just a tank)?  Should I add broken shells to the soil?  I don't know if I should treat the soil or the water.  I don't like adding the natural ph up to fertilizer water because i'm worried about the salt content when adding so much to neutralize the water.  I'd rather try and buffer with something that would add calcium and is more neutral.  Lime worries me a bit also.

Edited April 27, 2014 by Norby

[Norby]

Or could it be that my beneficial bacteria levels are down and they aren't neutralizing the fertilizer?  I read your not supposed to correct the ph of the fertilizer because the beneficial bacteria will take care of it.  Maybe I'm thinning out the beneficial bacteria and fertilizing with low ph water is killing them off?

[Chauncy Gardner]

Flush the soil with neutral pH water until you get the desired pH level, then adjust the nutrient water (after you have added the nutrients) to your desired pH. This is  the way I have always understood it. You may be over thinking it.

[Norby]

General organics q & a forum said that you shouldn't adjust the ph even in the lo 5's because the beneficial bacteria would buffer it or adjust it in some way.  I was worried because it's a lot of potassium bicarbonate to add to get the RO water from 5.8 to 7 and then more to get it from 5 back to 7 after adding nutes, esp when fertilizing 3-4 times a week.  I was wondering if I added powdered myco and bacteria to the schedule would it possibly fix the ph problem.  I'd rather add pulverized shells to buffer the soil mix or add mycos and bacteria if it'd lower the amount of fertilizing I'd have to do and fix the problem in the soil rather than add more potassium bicarb every time I fertilize.  I'll do that to the 2-3 plants I'm having problems with now.  I'm wondering if the red stems and yellowing leaves is from using organics and no having the bacteria load to convert the organic fertilizer and the ph isn't really the problem or wouldn't be if i had to fertilize less.  Even though the runoff on the plants is in the hi 5 to lo 6's it may be that the plants can't uptake the organic fertilizer for lack of mycos and bacteria and it's not the start of lockout.  I do a 50/50 perlite/happy frog or fox farm mix so it's kind of like an organic hydroponic system that's watered like a soil setup.  It's thinned so I have to add micro nutrients a couple times and cal mag most waterings.  It's different but i like to be able to just water the last 2 weeks and have no nutrients left in the soil before harvest and the roots make blocks of the soil.  It makes for a tempermental system and worked best when the water was naturally 7.5 - 8ph with a higher ppm of mostly calcium I imagine.  Now that I have a well and am using ro it's knocked things off.

[AmishRnot4ganja]

Mycos definitely help, but I think it is because they make nutrients more easily available to the plants. Soil pH in the high fives to low sixes should be fine, although mid sixes would be ideal.

I agree with Chauncy regarding flushing to correct soil pH. I also agree that water should be pH adjusted after nutrients have been added.

[phaquetoo]

I used to run into the same problems using pro mix and gh nutes and ro water, I went out and bought a 33 gallon plastic garbage can and I would put 30 gals in it put the nutes in and ph it, I would put a few bubblers in it and the ph would bounce up and down for at least a wk, after that I would get the ph good and it would stay, than I would use it, also every 3rd watering I would put just ph'd water in it to keep the ppm's down, also dont put anything in your pro mix for a week or 2, when Im ready to start another bucket I usualy water the promix w/o the plant in it yet to get the nutes and ph down, pro mix has alot of nutes and other stuff in it, and ive noticed it to work better if I watered it down a few times before I put clones in it!

 

what ever your nute instructions are cut it in half and see how you do, add as needed!

 

best of luck

 

Peace

[trichcycler]

can you show me the nute list in pro mix ?

[Norby]

For these I'm going to adjust the ph after adding the nutes to the water and I'm adding dolomite lime and oyster shell to my soil mix so that I don't have to worry about cal mag or ph problems in the future.  The dolomite lime should buffer well enough that it should keep the soil ph back in the 6's.  The oyster shell should add good places for beneficial bacteria to build also.  Got the true living organics book today and learned a bit.  Not going full out but I'm adding teas and the buffers and that should get it right where I want it.

Thanks for the replies.  I didn't know you could adjust the ph after adding the nutes.  i thought it would lock out the phosphorous or something.  A chemist I certainly am not.

[pergamum362]

That was probably where you were running into the ph problem. Happy growing.

[pergamum362]

I would actually consider adding the cal/mag to the ro wAter in the tank, while its sitting there, for better ph stability.

[AmishRnot4ganja]

For these I'm going to adjust the ph after adding the nutes to the water and I'm adding dolomite lime and oyster shell to my soil mix so that I don't have to worry about cal mag or ph problems in the future.  The dolomite lime should buffer well enough that it should keep the soil ph back in the 6's.  The oyster shell should add good places for beneficial bacteria to build also.  Got the true living organics book today and learned a bit.  Not going full out but I'm adding teas and the buffers and that should get it right where I want it.

Thanks for the replies.  I didn't know you could adjust the ph after adding the nutes.  i thought it would lock out the phosphorous or something.  A chemist I certainly am not.

Sounds like a good plan. You may find that a shot of calmag is still occasionally needed even with the dolomite lime in the mix for some strains. In any event, a shot of calmag occasionally seems to not harm the plants. I mix dolomite lime into my Promix yet I still add calmag to the nutrient solution every other watering with no ill effects.