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Persistent Ph problem

Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010
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)
Unfortunately, I spent alot of time hangin out with jarheads during my stint in the Seabees...:)
 

Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010

leebee77

New Member
Well there you have it, you should have skin thicker than most! I always like the Seabees, I always headed over to their site for chow. You guys know how to bivouac (steak and eggs for breakfast on the beach in Sardinia).
Ahh yes, I was also a Seabee and was Stationed at Capodichino Italy (outside of Naples) I spent many weekends in Sardinia!
 

YardDog35

Plant of the Month Winner - December 2011
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
Such a great chart. I agree. Watering with low 5 ph'd water intending to raise run off creates a ph roller coaster never allowing the plant all of its macro and micro nutes.



What kind of PH meter are you using?
 

stokesy

New Member
I have a great meter, after messing around with cheaper versions, I've got a Bluelab ph meter.
In the past, when the ph of the soil has been around 7.3 or so, I've flushed and flushed with say, 6.3 adjusted - but it takes HOURS and about 90 litres, to percolate through and get a good reading. And the same thing happens the next time I need to water. It's too much like hard work (which I don't normally mind), but to flush them every time is just not practical. I don't understand why most people have the opposite problem, (low soil ph), yet mine is always high...
Again , all input is welcome...
 

SteveHman

Member of the Month: Aug 2011 - Nug of the Month: Oct 2011
Stokesy,
You don't flush every feeding, but you do want some runoff every time.

When is the last time you calibrated your meter? I was chasing my pH around on my other grow and couldn't get it to stay where I wanted it. Turned out I need to calibrate the meter. Now I make it part of my routine to calibrate it at least once a month (or anytime my numbers seem way out of line). I ensure the readings are correct and then make any adjustments necessary.

What is the pH of you nute solution (without adding any pH down), just the water/nute mix?

It shouldn't take hours to percolate through, if it is you need to adjust that quickly. Soil or soiless media should drain fairly quickly, hold enough moisture for the plants to feed but not so much that is creates a rot-friendly environment.

If everything continues to go this way after you calibrate your meter. I suggest repotting them in a different soil. Make sure you add some perlite to the mix to allow better aeration and drainage, and possibly consider adding some coco as well. My mother plants are in a coco/perlite/vermiculite mix and they drain fast, and they need water every 3 days, so the coco holds enough to feed them and the res in the bottom of the hempy wicks up through everything. I use OC+ and straight filtered tap water and everything is fine with them. Never even worry about the pH with them (never checked run off, and they look healthy and need to be trimmed twice a week).

Do you have any pictures of the plants? Are they showing signs of deficiency that would indicate a lockout from pH?
 

stokesy

New Member
Hogdady, you're correct - I just don't get it. I understand WHY the ph should be kept within the desired range, but - I don't understand why my soil should have a rising ph, when others struggle with a low ph. I'm using Biomix light mixed with about 25% perlite, so there's good drainage..
I DO appreciate that it's not a great idea to water with 5.2 in order to bring the ph in line... but I just don't know how else to approach the problem.

Steveham. I check the meter every session. I have two jars, one at 4 ph, and the other at 10 ph. It's very easy to check. The meter is fine - 100%.
The water with just the noots is about 7 - 7.2.
All the plants previously showed distress shortly into the flowering phase, with dried up leaves. Leaves would go light green, yellow, and then go brittle. At the moment, the current grow is approaching the end of the third week. All looks ok so far.- but just checking my notes on a previous grow, the leaves turned light green at week 4 of flowering...
Incidentally, I'm using Biomix noots at half recommended strength, and during the last watering, added some Epsom Salts, just the one dessertspoonful to 25 litres of water...
I'm using Airpots, incidentally, and they're all LST'D. I'll post some pics later, but I'm busy for the next few days.
Thanks, all, so far!


Steveham,
 

Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010
I DO appreciate that it's not a great idea to water with 5.2 in order to bring the ph in line... but I just don't know how else to approach the problem.
Did you read the thread I provided a link to?
 

stokesy

New Member
Hogdady, thank you for your continued patience... but I'm slightly confoosed... i can appreciate the benefit of reducing the ph gradually - this is what I did first and second time around, but the ph was still golloping away, ph never going below 7. I was watering with around 6.5ph water and noots. Like I said - it took ages to get theat ph down.

I water all 6 at the same time, using a plastic tubular distribution system, one fat pipe, with 4 branches off for each pot. Not ideal, as the end ones don't get the same pressure.... but it's ok. That's how I've been doing it up until last week...now I do them all individually, by hand. A little at first, let it soak in for around 5 mins, then a bit more, 2 mins, then a bit more every 2 or three mins, so that it doesn't all slip away through the air pockets if there are any.
About watering. It's always been my understanding that they should be allowed to dry out (not beyond the point of stress) , and then thoroughly soaked. Which is what I do.
Every 7 to 10 days...may be less, now that they're in bloom...so my understanding is - you reckon I should water with LESS amounts, more frequently?

I was using Biobizz All Mix, with a ph (on the bag rating) of 6.6, but with a fairly high EC content.

On this grow, I'm using Biobizz light, from memory this has a similar ph, but a lower EC rating. So, if we assume that the starting point is - Soil 6.6ph. First water with 5.4, runoff 6.6 or thereabouts. Next watering, same deal, with most runoff reading around 6.9 ph.

(Tried to get the stats for Biobizz LIGHT mix, but the site seems to be down, and my bags are in the out-house....)
Down to 5.2ph feed on the third watering, again runoff reading around the 6.9 mark. (6 different plants, remember.. in 11 litre(2.4 uk gals, or 2.9 US gals) airpots, well mixed with perlite or the other one similar, oh yes, Vermiculite....I only have to water them every 7-10 days, not that frequently... so the gradual reduction of the ph would take quite some time, and hasn't worked with the first two grows.

They all seem healthy enough - but it's only just close to 3 weeks 12/12.

6 plants, 1.2m x 1.2m (15.5 sq ft ) tent, fan in, fan out, temperature running between 75 and 83 at times, 600 watt HPS about 24" above the tops of the ladies. Any lower, causes heat problems...

Plants are: Northern Lights, AK48, PPP.

I like the airpots a lot.

All for now...Thanks all! Keep them coming!!!
 

stokesy

New Member
3 weeks since my last post on this, and things seem to be going well...
The last two waterings seem to be a lot more consistent..
Watering with noots and ph adjusted to 5.8 ph, and the initial runoff is around 7.1
Kept watering till the runoff got to around 6.6/6.7.
So I appear to have reached some sort of stability.
This is only my third grow, and it looks much healthier, and heavier
than the first two.
 

YardDog35

Plant of the Month Winner - December 2011
3 weeks since my last post on this, and things seem to be going well...
The last two waterings seem to be a lot more consistent..
Watering with noots and ph adjusted to 5.8 ph, and the initial runoff is around 7.1
Kept watering till the runoff got to around 6.6/6.7.
So I appear to have reached some sort of stability.
This is only my third grow, and it looks much healthier, and heavier
than the first two.
:thumb: Great to hear stokesy! Keep up the diligent work and you will reap the benefits.
 

Droopy Dog

New Member
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..
Try mixing some dolomite lime into the soil. It should act as a buffer and lower the pH.
Alright, I'll take the long way around since the multi-quote just seems to want to do only 2 of 3 and not in order. If I had one of those voice to text programs, something would have melted by now.

Both stevehman and Be IRIE are more than correct. Dolomite does indeed work both ways. It's the AC/DC of rocks. LOL Neutral pH of 7 will bring down a high pH and bring up a low pH and keep it buffered (as noted), at ~6.8.

DD
 

Droopy Dog

New Member
None taken.... I always get that response, then they try it, then it is answered...... :)
A 40lb bag cost ~$5 at Lowes or HD.

For that, you could snag a bag, try it on ONE plant and see what happens. About the worst is, you would be out $5.

The best is, you would never have to worry about pHing again. I pH nothing that goes on my plants. Not water, or nutes, or teas, or whatever. It's just not necessary with a well buffered soil/mix.

Hydro is a different story, but soil is sooooo simple.

DD
 

Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010
What's the difference between dolomite lime and garden lime, anyone, please?
Same thing, just be sure it isn't hydrated lime (a little too strong)....
 
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