What can change PH?

Loc Dog · Jan 5, 2016

I have been using coco for over a year, and going back to flood and drain ASAP (about 2 months). I make the nutrients and bubble overnight. Using GH Flora series (Micro, Grow, Bloom, Rapidstart, Diamond nectar, KoolBloom, Floralicious, Florblend, Floranectar), Great White (myc), Chitosan Oligosaccharide, and occasionally BTI (mosquito dunks).

The PH always goes down, before I use it. Also have a problem that runoff is VERY low. Many times around 5.0, feeding at 6.0.

Could one of those products be the problem???

Thanks!!

Chimera · Jan 5, 2016

EC/PPM?

Often it is due to the plants using more water than salt, creating a salt increase in the substrate, and crashing the pH.

That's a pretty complex diet also, do you feel you need everything in there? It's a complex secret sauce my friend.....

Loc Dog · Jan 5, 2016

Chimera said:
EC/PPM?

Often it is due to the plants using more water than salt, creating a salt increase in the substrate, and crashing the pH.

That's a pretty complex diet also, do you feel you need everything in there? It's a complex secret sauce my friend.....

I used to grow in flood and drain, and everyone was saying how great coco is, so switched. I suck at reading plants, so just using the full GH Flora series. Had thrips and mites devastate last batch, so feeding the Chitosan and BTI. The Great white is getting old so trying to use it up.

I have been letting it dry out a little before watering, might need twice a day. Rinsed it with Florakleen a few days ago. Was feeding 600 PPM (gorilla glue #4) and runoff was between 1000 and 2500. Now back down.

Can not wait to do hydro again. Starting rooted cuttings for that when I get done watering the coir.

Thanks for the reply!!!

stoned40yrs · Jan 5, 2016

That bubbling doesn't help. All them additives might not help. That said all I use is micro and bloom with a little silica in a 35 gal rez and that stuffs ph goes down daily. I have to add ph up every other day. It falls from 6.2 to 5.5 fast.

PetFlora · Jan 5, 2016

I find pH drops from ~ mid-flower on. seems to have something to do with bud building

I have to adjust daily then, but it doesn't take much UP to bring it back

Dkgrower · Jan 7, 2016

Things in your fertiliser that can lower pH are sulfur, ammonium lowers the pH. and can be used to fix and control the pH in you medium and hence since the run of is in equilibrium with that so my best guess is your N profile is strong on ammonium and low in nitrate.. sulfur would just push the trend of lowering the pH since they also lowers the pH in the medium as microbes feast on them.....

I agree with mr C, hella lot of products you loose so much controll when you use that many impossible to ever see what works or not... =)

Limeygreen · Jan 11, 2016

pH can also drop when more cations are taken up, they take place of Hydrogen in the root zone, when there is a heavy pull on a cation pH will generally drop. Lower drain pH than feed pH can be that your plant is becoming vegetative, when it starts to rise in the drain above your feed you could be taking up more anions leaving H in the root zone and making the plants more generative. Say there is a heavy nitrogen and calcium pull by the plant, you may see your pH drop, once there are huge potassium pulls you may notice your pH rise slightly, such as flowers bulking up and putting on weight. My experience is more related to vegetables but I would imagine that it applies to any plant grown hydroponically none the less, please correct me if I am wrong, I would like to know.

noodles05 · Jan 11, 2016

It sounds like your bang on the bud Limeygreen
All salts-Elemements (N-P-K) have an ionic charge which affects there ph.
By mixing a lot of different products together, its hard to say whats happening to the ph,
or wether there is any sort of precipitation (lockout) of certain nutrients.
Usually adjusting ph after mixing the products is standard practice.
A shift in ph is normal (the plant is eating)....different strains can be picky and will pick n choose what they want from the nutrients.

As to what changes the ph... you can use phosphoric acid to lower, and potassium hydroxide to raise the ph.
These are usually available as buffer products and because the contain P&K, they are ideal for budding enthusiasts.
If you can get your hands on it, mono-potassium phosphate is great for lowering ph and buds love it, di-potassium phosphate will raise the ph......all the best man

Loc Dog · Jan 11, 2016

noodles05 said:
It sounds like your bang on the bud Limeygreen
All salts-Elemements (N-P-K) have an ionic charge which affects there ph.
By mixing a lot of different products together, its hard to say whats happening to the ph,
or wether there is any sort of precipitation (lockout) of certain nutrients.
Usually adjusting ph after mixing the products is standard practice.
A shift in ph is normal (the plant is eating)....different strains can be picky and will pick n choose what they want from the nutrients.

As to what changes the ph... you can use phosphoric acid to lower, and potassium hydroxide to raise the ph.
These are usually available as buffer products and because the contain P&K, they are ideal for budding enthusiasts.
If you can get your hands on it, mono-potassium phosphate is great for lowering ph and buds love it, di-potassium phosphate will raise the ph......all the best man

I am using this -

http://generalhydroponics.com/site/gh/docs/feeding_sched/GH_FloraSeries-Expert.pdf

Plus Great white Myc, and Chitosan Oligosaccharide.

I am so back to hydro, and dumping coir. I love an inert medium.

Thanks!!

Granger2 · Jan 11, 2016

Loc,
How do your plants look? Are you having problems? If not, why worry about all this shit? I've never checked pH of runoff. If I were having problems that I couldn't fix some other way, I would check it. Good luck. -granger

MisterBlah · Jan 12, 2016

If you're pH is changing that quickly, you need to increase the buffering capacity of your water. For hydroponics, to improve the buffering capacity of your water for pH decreases, you need to increase the amount of phosphate in the water. To improve the buffering capacity for pH increases, you need to add carbonate.

In your case, it's a pH decrease. So, adding some monoammonium phosphate or monopotassium phosphate will solve the problem.

To increase your phosphate concentration by 50ppm, do one of the following:

add 96mg/L of monopotassium phosphate (will increase potash(K2O) by 33ppm)
or
add 80mg/L of monoammonium phosphate (will increase total nitrogen by 9.7ppm)

If you don't want to make your own phosphate stock solution, then just find some PK booster and use that. All PK Boosters are monopotassium phosphate and dipotassium phosphate.

I can't say the exact amount you need to solve your problem. I can only guide you in the right direction.

Loc Dog · Jan 12, 2016

MisterBlah said:
If you're pH is changing that quickly, you need to increase the buffering capacity of your water. For hydroponics, to improve the buffering capacity of your water for pH decreases, you need to increase the amount of phosphate in the water. To improve the buffering capacity for pH increases, you need to add carbonate.

In your case, it's a pH decrease. So, adding some monoammonium phosphate or monopotassium phosphate will solve the problem.

To increase your phosphate concentration by 50ppm, do one of the following:

add 96mg/L of monopotassium phosphate (will increase potash(K2O) by 33ppm)
or
add 80mg/L of monoammonium phosphate (will increase total nitrogen by 9.7ppm)

If you don't want to make your own phosphate stock solution, then just find some PK booster and use that. All PK Boosters are monopotassium phosphate and dipotassium phosphate.

I can't say the exact amount you need to solve your problem. I can only guide you in the right direction.

Thanks!!

MrBungle · Jan 12, 2016

a lil bit of gypsum in your coco will buffer well... And I'd stay away from anything with Ammonium or Urea if your pH is running low.. it will continue to lower your pH... If I had to guess your pH lowering culprit, it would be the grow part of your 3 part nutes...

MisterBlah · Jan 12, 2016

MrBungle said:
a lil bit of gypsum in your coco will buffer well... And I'd stay away from anything with Ammonium or Urea if your pH is running low.. it will continue to lower your pH... If I had to guess your pH lowering culprit, it would be the grow part of your 3 part nutes...

Gypsum, or calcium sulfate dihydrate, has very poor solubility in water, therefore it is not often chosen as a chemical buffer in hydroponics.

Dkgrower · Jan 12, 2016

MrBungle said:
a lil bit of gypsum in your coco will buffer well... And I'd stay away from anything with Ammonium or Urea if your pH is running low.. it will continue to lower your pH... If I had to guess your pH lowering culprit, it would be the grow part of your 3 part nutes...

I second that motion, well written.. wish i was better at english

swap that growth formular with a product where N is 100% nitrate based.

Doing that u get fix u pH more, get better uptake of trace elements but the biggest bonus is you can push your fertiliser to higher PPM levels if you wanna try and see how much u can push the plant yeild wise...

BTW why did you move from hydro to coco.. u looking for more flavor ?

Loc Dog · Jan 12, 2016

Dkgrower said:
I second that motion, well written.. wish i was better at english

swap that growth formular with a product where N is 100% nitrate based.

Doing that u get fix u pH more, get better uptake of trace elements but the biggest bonus is you can push your fertiliser to higher PPM levels if you wanna try and see how much u can push the plant yeild wise...

BTW why did you move from hydro to coco.. u looking for more flavor ?

The source of my GG4 recommended it, and several GG4 growers were using it. Was supposed to be easier, but has been nothing but trouble. More money on fertilizer, more RO water, PH problems, PPM problems, hand watering, hand removal of runoff, bugs, mess, larger pots, etc..

MrBungle · Jan 12, 2016

MisterBlah said:
Gypsum, or calcium sulfate dihydrate, has very poor solubility in water, therefore it is not often chosen as a chemical buffer in hydroponics.

You are correct... And I thought about this after i replied... but I believe he was looking for something to buffer the coco.. not the solution... so I addressed both... the soil acidifier (NH4 in solution)... and the buffer for the coco (gypsum)

MisterBlah · Jan 12, 2016

MrBungle said:
You are correct... And I thought about this after i replied... but I believe he was looking for something to buffer the coco.. not the solution... so I addressed both... the soil acidifier (NH4 in solution)... and the buffer for the coco (gypsum)

Whoops! And that's where I glossed over it. I suppose I should have read his post more carefully. In such a case, doing both would probably be okay.

Planes · Jan 12, 2016

Loc Dog said:
The source of my GG4 recommended it, and several GG4 growers were using it. Was supposed to be easier, but has been nothing but trouble. More money on fertilizer, more RO water, PH problems, PPM problems, hand watering, hand removal of runoff, bugs, mess, larger pots, etc..

Appreciate the honesty. I have considered making the switch, but i'll stick with my current setup.

Granger2 · Jan 13, 2016

Actually gypsum, if in dust form, is fairly well soluble and has a pH of 7.0. From Wikipedia
https://en.wikipedia.org/wiki/Gypsum
"Physical properties
Gypsum is moderately water-soluble (~2.0–2.5 g/l at 25 °C)[6] and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures. When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, (bassanite, often simply called "plaster") and, if heated further, to anhydrous calcium sulfate (anhydrite). As for anhydrite, its solubility in saline solutions and in brines is also strongly dependent on NaCl concentration.[6]

Gypsum crystals are found to contain anion water and hydrogen bonding."

I've been topdressing with it on coco, and it disappears quickly. Some dissolves quickly, some washes into the medium. -granger

What can change PH?

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