pH problem that flushing won't fix

[Young Yoda]

I have recently developed a pH problem, which I though was a mag deficiency due to lower yellowing leaves. Realized today that my runoff is coming out at 5.
My tap water comes out at under 150ppm and at a pH of just about 7, and I've now flushed about 8 gallons of it through my 2-3gallon root ball. pH is still 5..

I need an emergency pH raising method pronto.

I have a 5gal pot ready to go with new soil that is presumably not encrusted with salts as my current soil obviously is, but I don't know that just adding more soil around the rootball will be enough.. Did I mention the plant is kinda rootbound..

 

[Marzbadrock]

If you are using fox farm soil this is a normal thing with the ph. When wet the soil will drop to as low as 4.7 then as it dries out it will rise to as high as 7.

 

[Ripples]

Soil

Water going in should be 6-7 pH

If runoff pH is...
6-7 pH - in the right range, no changes needed.
Less than 6 - provide next watering at pH 7
More than 7 - provide next watering at pH 6

Continue this formula with each watering.

 

[Young Yoda]

If you are using fox farm soil this is a normal thing with the ph. When wet the soil will drop to as low as 4.7 then as it dries out it will rise to as high as 7.

Wow.. Thanks for pointing that out but I'm not in ffof. Do you know what it is about the stuff that causes that though?

Soil

Water going in should be 6-7 pH

If runoff pH is...
6-7 pH - in the right range, no changes needed.
Less than 6 - provide next watering at pH 7
More than 7 - provide next watering at pH 6

Continue this formula with each watering.

Thank you. That's about as simple as I've seen it put!

That being said, I haven't been testing my runoff, so now that I paddled myself up shit creek, I'm looking for a way back.. I mean I flushed the damn thing with like 10gallons of pH 7 water and it was still coming out at 5.

Well, for now I've decided just to transplant to the 5 gal pot with fresh soil and hope for the best.

 

[Scarfinger68]

1 tablespoon of garden lime per gallon of water

 

[Weaselcracker]

Just something I read on Ultradan's journal-
Flushing with a higher ppm water will change the ph more effectively than low ppm water. However you go about getting that high ppm. UltraDan did it by adding a bunch of lime till he had water (water/lime solution, that is) with a high ppm.
Have you noticed how it takes more ph-up, or ph-down, to change the ph of a high ppm solution - like water mixed with nutes, than it does to change the ph of plain water? The opposite applies too. So if you want to shift your soil ph it's going to take a whole lot of plain water to do that, or you could do it faster by running a high ppm solution through there.

 

[Young Yoda]

Just something I read on Ultradan's journal-
Flushing with a higher ppm water will change the ph more effectively than low ppm water. However you go about getting that high ppm. UltraDan did it by adding a bunch of lime till he had water (water/lime solution, that is) with a high ppm.
Have you noticed how it takes more ph-up, or ph-down, to change the ph of a high ppm solution - like water mixed with nutes, than it does to change the ph of plain water? The opposite applies too. So if you want to shift your soil ph it's going to take a whole lot of plain water to do that, or you could do it faster by running a high ppm solution through there.

That makes a lot of sense and probably explains my flushing problem. Thanks!

Regarding lime, do I recall that it acts as a buffer? Or does it just add alkalinity?

 

[Young Yoda]

Link me to Ultradan's journal? I couldn't find it


For anyone who cares, found this by Ulysses back from 2007, sure wish I had seen it before. Only thing is it takes time to react..

"If you have organic fertilizer in your soil, you need Pulverized Dolomite Lime. Most fertilizers almost always change the pH of the growing media lower (more acidic). Dolomite Lime stimulates the decomposition of this organic matter. Also, rain water is often acidic. A bag of Pulverized Dolomite Lime will take care of Cal/Mag issues and pH problems yet a 40 pound bag of it is often less than 5 bucks. It should be first on you list of soil amendments! Get the big bag! That sucker is heavy, yeah! You will need 2 Tablespoons per gallon of soil. 1 cup for 8 gallons of soil- if my math is correct… It goes fast at that rate!"

 

[Weaselcracker]

Here young Yoda. UltraDan's First Grow - White Widow - Flux - 2015. As a wild guess, the pages that I was talking about are probably about two thirds of the way through the journal. Yes dolomite lime is the stuff we are talking about - the most appropriate one for putting in the soil. There are several kinds of lime.
I will try to answer your question better possibly late tonight. And if you don't find that info in Ultradan's journal I will dig it up for you. Too busy To write more atm.

 

[Young Yoda]

Found it! According to dan it does buffer to 6.5.
As a side note, wow he knows what hes doing.. Thank you so much for that journal that was friggin gorgeous

 

[jojo677]

Out of curiosity, what soil are you using? And yes, Ultradan had one of the best first grows shared around these parts!

I used lime for my first grow to raise the pH, and it tended to buffer it to 6.5-7.0. I dissolved it in water to help adjust the pH of the pH of the medium, and then I amended some into the top of the medium so it would get a dose each time I watered.

 

[Young Yoda]

Mushroom compost amended with an organics sampler i bought off ebay.. I don't recall exactly but it had loads of stuff, mineral amendments, bat/worm poo, etc. etc.

Nice journal!! Looks like I have a similar pair of LEDs to yours. Reading my way through your adventures now.

 

[jojo677]

Alright, just curious about the soil, since many people think they are using soil, and are actually using soiless mediums. You should be fine though! And thank you, the journal has given me motivation to keep on top of things!