The PH Thread.....Runoff PH??

[Caninobis]

So I've recently been working on dialing in the PH for my indoor soil grow . Which is actually a lot harder than I thought it would be. Most likely because i used a peat pod to start my seed in and as we all know peat is acidic AF and they're not great starters for cannabis plants.

- Anyway, I've been testing my runoff to see what my water is coming out of the pot at and it's coming out 1-1.5 lower than what I put in. I typically PH down to 6.0-6.5 and the run off is coming out at a 5.0-5.5. Is this a problem? If so, how do i fix it? The acidity from the peat shouldn't last much longer.

- Should I leave my water PH'ed a little high so that when it passes through the soil its coming out on point? The plants don't seem to be showing any signs of stress and at about 14-18 days old (from seed) are already about 4 nodes tall with big beautifully green fan leaves and just beginning to start branch growth.


- I don't have a digital meter and the color chart isn't all that accurate but its obvious that the water is going in yellow and coming out a yellowish orange

 

[Beachwalker]

The acidity is not from the Little Pete pot, what kind of soil do you have?

In soil lock your pH at 6.5

Flush your medium if it's 5.0 cuz that's far too low

and add a tablespoon per gallon of soil Dolomite lime to your next mix

and if those were my readings on my plants I'd cast 1 tablespoon dolomite on top of the soil and water it in next watering

And use something like this 5 bucks Amazon

 

[PipeCarver]

So I've recently been working on dialing in the PH for my indoor soil grow . Which is actually a lot harder than I thought it would be. Most likely because i used a peat pod to start my seed in and as we all know peat is acidic AF and they're not great starters for cannabis plants.

- Anyway, I've been testing my runoff to see what my water is coming out of the pot at and it's coming out 1-1.5 lower than what I put in. I typically PH down to 6.0-6.5 and the run off is coming out at a 5.0-5.5. Is this a problem? If so, how do i fix it? The acidity from the peat shouldn't last much longer.

- Should I leave my water PH'ed a little high so that when it passes through the soil its coming out on point? The plants don't seem to be showing any signs of stress and at about 14-18 days old (from seed) are already about 4 nodes tall with big beautifully green fan leaves and just beginning to start branch growth.


- I don't have a digital meter and the color chart isn't all that accurate but its obvious that the water is going in yellow and coming out a yellowish orange

I'm having a very similar issue growing in ProMix. I ph my feed & waterings to 6.5 -6.6 and started having leaf issues so after consulting here and reviewing my RO ph I find I'm in the same boat as you with 4.8 & 4.9 ph readings. I've been flushing with a high ph water 8.4 to see if It would move the needle upwards without much luck I'm still around 5.1 -5.2. I've just been advised to try a small amount of Dolomite to the top soil to help balance the ph to a more neutral state.

 

[Beachwalker]

I've never seen Dolomite hurt when used in soil as directed, however promix is different, I don't know the right amount to use in promix?

maybe @Jimster knows, he's been using it for a long time and was kind enough to answer some questions about promix for me when I started using it recently too

 

[oldskol4evr]

why not do a slurry test,doesnt matter if soil or pro mix,the slurry will tell you your medium ph ,then you have something to work with as far as your runoff goes,you use lime and it brings the ph to a neutral 7,unless you do it over weeks of small increments at a time,just throwing in a couple spoon fulls could raise you to neutral and then only way you get it back to acidic soil is adding more peat moss to drop ph,7 is to high for the medical plant in my opinion,i keep mine right at 6.5 and feed the same,never have checked runoff,really cant unless you have a whole mess of runoff,like about 1 1/2 inches to,all the floaters and wash effect the pen unless you get it in there,that what she said by the way hahahah,but take time to do a slurry before you go adding or flushing,then you got something to work with,all this is just my opinion hahah,i find it is best to say that a lot on this forum hahahah

 

[Caninobis]

The acidity is not from the Little Pete pot, what kind of soil do you have?

In soil lock your pH at 6.5

Flush your medium if it's 5.0 cuz that's far too low

and add a tablespoon per gallon of soil Dolomite lime to your next mix

and if those were my readings on my plants I'd cast 1 tablespoon dolomite on top of the soil and water it in next watering

And use something like this 5 bucks Amazon
View attachment 904198

I'm using Fox Farm Happy Frog. I'm referring to the water going in and coming out of the soil not the soil it self. For the dolomite lime, you would do the tablespoon per gallon and sprinkle some on top or do you mean one or the other?

 

[Beachwalker]

I mean one level tbsp per gallon of soil next time you mix up some soil. If you'd rather use less do so, as you can always top-dress later if runoff dictates

for the existing plants I would top dress a tablespoon on the soil and then water it in

Always use 6.5 in soil for best results

 

[Caninobis]

why not do a slurry test,doesnt matter if soil or pro mix,the slurry will tell you your medium ph ,then you have something to work with as far as your runoff goes,you use lime and it brings the ph to a neutral 7,unless you do it over weeks of small increments at a time,just throwing in a couple spoon fulls could raise you to neutral and then only way you get it back to acidic soil is adding more peat moss to drop ph,7 is to high for the medical plant in my opinion,i keep mine right at 6.5 and feed the same,never have checked runoff,really cant unless you have a whole mess of runoff,like about 1 1/2 inches to,all the floaters and wash effect the pen unless you get it in there,that what she said by the way hahahah,but take time to do a slurry before you go adding or flushing,then you got something to work with,all this is just my opinion hahah,i find it is best to say that a lot on this forum hahahah

Whats a slurry?

 

[Aqua Man]

I'm with @Beachwalker and @oldskol4evr. You need to build your soil to a proper ph to begin with. Not pour high ph water or alter after. Before using you want to slurry test the ph of the soil.

This way your soil will always steer the ph of your feed towards your ideal ph. If not you will be chasing your tail all through the grow.

This is why I often say in soil it's the soil that buffers the ph.

@Jimster uses wood ash I believe in promix to increase the ph of his soil... He can correct me if I'm wrong.

 

[Aqua Man]

It's my honest opinion and only that my opinion if you build your soil right there is no need to ph nutrients. While you should still check run off for an indication of nutrient build up (shown by lower ph) or when using tap, well water, hard water, with high carbonate/bicarbonate ( an increase in runoff ph).

 

[Aqua Man]

 

[Sunday687]

I agree with previous posters do a slurry test run off ph testing in soil is a fools errand everything breaks down at different times. I never test runoff ph and my plants always make it to harvest lol

 

[Jimster]

I'm with @Beachwalker and @oldskol4evr. You need to build your soil to a proper ph to begin with. Not pour high ph water or alter after. Before using you want to slurry test the ph of the soil.

This way your soil will always steer the ph of your feed towards your ideal ph. If not you will be chasing your tail all through the grow.

This is why I often say in soil it's the soil that buffers the ph.

@Jimster uses wood ash I believe in promix to increase the ph of his soil... He can correct me if I'm wrong.

.
I prefer less additives in my soil for the same reason that you are having issues... the makeup of the soil is fairly unknown, the nutrient levels are suceptable to variations, and adding other compounds can set off a whole slew of unintended reactions. My advice would to take a deep sample slurry... just a sample that is taken from deeper into the soil/medium. Sometimes channels develop inside buckets and containers and allowing the water and stuff to go thru the areas that are lowest resistance and not getting water and nutriets in a consistent manner. These are all possibilities that will drive you crazy

 

[Dirtbag]

Slow down a bit... Is your plant showing signs of nutrient deficiency or burning? Or is it growing ok?

I advise never checking soil ph runoff, you're far better off doing a slurry test. Soiless like coco or rockwool sure, but stuff that has nutrients mixed in it can be very misleading and can cause you to attempt to correct problems that arent actually a problem, and 9 times out of 10 you just make things worse. If the plants are consuming a lot of positively charged nutrients like calcium or potassium, the roots can exude negatively charged hydronium ions that lower ph runof also, doesnt always mean there is a problem.

 

[Aqua Man]

Slow down a bit... Is your plant showing signs of nutrient deficiency or burning? Or is it growing ok?

I advise never checking soil ph runoff, you're far better off doing a slurry test. Soiless like coco or rockwool sure, but stuff that has nutrients mixed in it can be very misleading and can cause you to attempt to correct problems that arent actually a problem, and 9 times out of 10 you just make things worse. If the plants are consuming a lot of positively charged nutrients like calcium or potassium, the roots can exude negatively charged hydronium ions that lower ph runof also, doesnt always mean there is a problem.

Good point

 

[JWM2]

Potential Hydrogen drifting down in soil is usually an indicator of nutrient or salt buildup. A good flushing will help bring the ph back up to where it needs to be or you can bind the excess nutrients with calcium to render them null.

My favorite tactic is to do a nectar for the gods flush. To do this you need Herculean Harvest and Olympus Up. Mix in the HH first and then ph adjust it to 6.8 before applying to your soil. One good application of this until 20% runoff will do wonders and you’ll see almost immediate improvement. Then on the next feeding hit them with 1/2 strength nutrients and you’re off. Do this flush every two weeks or so when needed.

When nutrients build up in the soil they can have an adverse effect on the ph and soils microbial life. So either way you go you’re going to need to get those excess nutrients out of your soil by flushing or binding them up.

 

[Dirtbag]

Potential Hydrogen drifting down in soil is usually an indicator of nutrient or salt buildup. A good flushing will help bring the ph back up to where it needs to be or you can bind the excess nutrients with calcium to render them null.

My favorite tactic is to do a nectar for the gods flush. To do this you need Herculean Harvest and Olympus Up. Mix in the HH first and then ph adjust it to 6.8 before applying to your soil. One good application of this until 20% runoff will do wonders and you’ll see almost immediate improvement. Then on the next feeding hit them with 1/2 strength nutrients and you’re off. Do this flush every two weeks or so when needed.

When nutrients build up in the soil they can have an adverse effect on the ph and soils microbial life. So either way you go you’re going to need to get those excess nutrients out of your soil by flushing or binding them up.

Which begs the question, what is the runoff ppm?

But I'd have to agree. Since he doesnt have meters or a way to accurately test things, following your suggestion of rinsing a bit would be wise.

 

[Aqua Man]

You dirt guys make me feel "special" to be politically correct. I have a good idea of hydro but wow it's a different world in soil. I'm slowly Pickin this all up.

 

[Dirtbag]

I just re-read they're in FFHF soil, are you feeding them nutrients also or just water?

If just water, you could be just watering too often, releasing too many nutrients. Not enough dry back. If that's the case, flushing or rinsing would be a bad idea. You'll just release more nutrients and make things worse.

 

[Dirtbag]

You dirt guys make me feel "special" to be politically correct. I have a good idea of hydro but wow it's a different world in soil. I'm slowly Pickin this all up.

It can be a frustrating world in soil lol. I'm going the other way and moving to hydro to get more control. Hydro at least has more absolutes, soil can be a guessing game at the best of times.