Persistent Ph problem

[stokesy]

I'm on my third grow, in soil, Biomix light with perlite...
Current grow is AK48, PPP, Northern Lights, all femenized.

Problem is high ph.. everything starts off great with a ph of 7 - I adjust that by watering with ph adjusted to 5.2/5.4. And that corrects the ph, according to the runoff to around 6.6- 6.9.
Next time I water with 5.4 and the runoff is back up high again, to perhaps 7.2 or 3, till I run it through a bit more, and get it back within the 6.3 to 6.9 target range.

Previous two grows, I didn't correct enough, I was starting high with the Biomix standard, and didn't ever correct enough. (never considered going as low as 5.2 before.)
Consequently, the results were ok, but not nearly as good as they should have been.

This seems to run against what I read on here - seems most everyone else has a problem with LOW ph runoff..

How come I seem to be the only one with HIGH ph?

I'm using rainwater, adjusted after adding noots, with lemon juice.

Another question - I read somewhere that lemon juice "degrades"...if this is the case, how so? And are there any problems associated with using lemon juice as a ph down? I use the stuff out the plastic bottle, rather than fresh. I find it easier to use than standard aquarium ph downs.

Can anyone explain how this works?

It seems to me that the plants suck up the low ph water, causing an imbalance in the soil, but I'm pretty sure SOMEONE out there will have a more precise and easily explainable solution.

 

[SteveHman]

Try mixing some dolomite lime into the soil. It should act as a buffer and lower the pH.

 

[Hogdady]

Try mixing some dolomite lime into the soil. It should act as a buffer and lower the pH.

Dolomitic lime raises ph.....

 

[Be Irie]

Dolomitic lime raises ph.....

Dolomite works both ways... you can stabilize a high PH with it..... It usually brings the PH up to around 6.8 and will drop it down to close to 7..

 

[Hogdady]

I'm on my third grow, in soil, Biomix light with perlite...
Current grow is AK48, PPP, Northern Lights, all femenized.

Problem is high ph.. everything starts off great with a ph of 7 - I adjust that by watering with ph adjusted to 5.2/5.4. And that corrects the ph, according to the runoff to around 6.6- 6.9.
Next time I water with 5.4 and the runoff is back up high again, to perhaps 7.2 or 3, till I run it through a bit more, and get it back within the 6.3 to 6.9 target range.

Previous two grows, I didn't correct enough, I was starting high with the Biomix standard, and didn't ever correct enough. (never considered going as low as 5.2 before.)
Consequently, the results were ok, but not nearly as good as they should have been.

This seems to run against what I read on here - seems most everyone else has a problem with LOW ph runoff..

How come I seem to be the only one with HIGH ph?

I'm using rainwater, adjusted after adding noots, with lemon juice.

Another question - I read somewhere that lemon juice "degrades"...if this is the case, how so? And are there any problems associated with using lemon juice as a ph down? I use the stuff out the plastic bottle, rather than fresh. I find it easier to use than standard aquarium ph downs.

Can anyone explain how this works?

It seems to me that the plants suck up the low ph water, causing an imbalance in the soil, but I'm pretty sure SOMEONE out there will have a more precise and easily explainable solution.

Please correct me if I'm wrong, but it sounds like you are watering with low (5.2/5.4) ph solution to bring the soil ph down to where you want it. Is this correct?

 

[Hogdady]

Dolomite works both ways... you can stabilize a high PH with it..... It usually brings the PH up to around 6.8 and will drop it down to close to 7..

No disrespect, but with dolomite being alkaline, I would have to see that to beleive it.....

 

[Be Irie]

None taken.... I always get that response, then they try it, then it is answered......

 

[Goldengoose7]

I would PH balance several gallons of water and use that to FLUSH your soil for about 7 days with nothing but this PH balanced water. Be sure to give a good dryout period in between each flush.

Also... You might try using a different potting soil. I swear by my long time 50/50 mix of Black Gold CocoBlend Waterhold and everyone's favorite CHEAP dirt... Hyponex from Scotts. I get great results using this soil mixture in pots.

Cheers.

 

[SteveHman]

That's why I referred to it as a buffer. It is used in aquariums to maintain a more constant pH as well.

 

[Hogdady]

None taken.... I always get that response, then they try it, then it is answered......

Have you ever dissolved dolomite in water and see what happens to the ph? Goes above 10.....

 

[Hogdady]

That's why I referred to it as a buffer. It is used in aquariums to maintain a more constant pH as well.

It is used far more extensively in agriculture......

 

[stokesy]

Hogdady - your assumption is correct. It makes sense to me, but I'm just learning....!
Anything you can help with would be VERY much appreciated. I've read many of your previous postings, and I'll take any advice from you as being the best. .... but I may still ask questions for my own learning curve...

 

[stokesy]

Incidentally, I just checked the ph of the original solution I watered them with 2 days ago, and the ph has jumped from about 5.2 to 7.2. This must be due to some later chemical reaction - perhaps the deterioration of the lemon juice? Or perhaps the solution has gone off, but it's been airstoned all the time. It looks cloudy - so SOMETHING has changed!

 

[Be Irie]

I am not here to argue with you guys, I will offer solutions to problems... Take it or leave it.... GL with your grow......

 

[Hogdady]

I am not here to argue with you guys, I will offer solutions to problems... Take it or leave it.... GL with your grow......

My friend, your comments are always welcome and respected by me. I may not fully understand something you say, but I will always take what you say for trusted information...

 

[Hogdady]

Hogdady - your assumption is correct. It makes sense to me, but I'm just learning....!
Anything you can help with would be VERY much appreciated. I've read many of your previous postings, and I'll take any advice from you as being the best. .... but I may still ask questions for my own learning curve...

Here's the problem with what you are doing, as I see it. Raisng or lowering the ph of your feed/water to influence your runoff ph is not advised. Your feed/water ph should be a consistent and accetable ph for your media. I prefer a range of 6.3 to 6.5 for soil and soiless mixes. This is not set in stone, as I know others have their own ideas. I find this value is a good range for nutrient uptake.

In checking runoff, start with neutral ph water. The soil should be dry. Add water to your pot until it begins to flow from the drains. Collect some of the first water out of the pot and check ph. It should be relatively close (within half a point) to the ph of the water you poured in. If not, you will need to amend the soil with dolomite. If Be Irie says that it will buffer high ph, I beleive him.

FYI - I use vinegar as a ph down in my feed/water

 

[Hogdady]

Here's a little read for ya....

How Can I Raise or Lower the pH of my Soil Mix?

 

[SteveHman]

Have you ever dissolved dolomite in water and see what happens to the ph? Goes above 10.....

"Dolomite has a neutral pH of 7.0 and can never raise the pH above 7.0"
Cervantes Grower's Bible, pg 216

If your pH rises then it is something else.I don't just pull info out of my butt. I try to make sure I give a researched answer to a question.

 

[Hogdady]

"Dolomite has a neutral pH of 7.0 and can never raise the pH above 7.0"
Cervantes Grower's Bible, pg 216

If your pH rises then it is something else.I don't just pull info out of my butt. I try to make sure I give a researched answer to a question.

I'm very certain I wouldn't want anything out of your butt!

Perhaps I spoke prematurely, since I've always used dolomite to keep my soil ph up, I was a little quick to correct you.

Can I give you some excellent medicine as a peace offering?

 

[SteveHman]

I'm very certain I wouldn't want anything out of your butt!

Perhaps I spoke prematurely, since I've always used dolomite to keep my soil ph up, I was a little quick to correct you.

Can I give you some excellent medicine as a peace offering?

Hogdady,
No offense taken, no apology required. I will however have a taste of those tasty nugs.

(sometimes I come off a little gruff, 23 years in the Marines will do that to you. The meds are helping mellow me out though)