Ph runoff Issues

[themastermind]

So last Thursday I flushed my plants for the first time and found alarming results. Some of the plants runoff was ~ 6.2 when the intitial solution was ~6.65 these plants are not a big deal I will just water them with a 7 ph solution.:) The problem is that I have a couple of plants with a runoff of ~ 5.75 when the solution being put in was around 9 ph. So now the question is do i flush the plants untill the runoff is at a good level or do i continue to use a 9 ph solution in watering to try and gradually bring up the ph.

[Faddenator]

So last Thursday I flushed my plants for the first time and found alarming results. Some of the plants runoff was ~ 6.2 when the intitial solution was ~6.65 these plants are not a big deal I will just water them with a 7 ph solution.:) The problem is that I have a couple of plants with a runoff of ~ 5.75 when the solution being put in was around 9 ph. So now the question is do i flush the plants untill the runoff is at a good level or do i continue to use a 9 ph solution in watering to try and gradually bring up the ph.

How long have they been in their current soil? it may be time to re-pot or transplant. Usually after 6-8 weeks the buffering agents start to dissolve and flush out causing ph swings.

[themastermind]

thats a story all in itself. 4 plants have been in MG for 7 weeks and 4 others have been in a combination of fox farm classic and MG for 5 weeks. Initially I had only a drop ph kit so I have determined that my ph was way too low for the first 4 weeks. I just got a hanna ph meter and am attempting to begin to regulate the soil ph. The problem is that I cant continue to flush the ones with the MG soil because it holds water for at least a week after due to MG soils terrible drainage.:mad:

[khyberkitsune]

It is well past time for you to transplant to new medium, and on top of that, you've got severe acidity buildup starting to occur. When pH 9 water runs off at pH 5.75 or lower, you can bet your soil is running 4-5 if not lower.

Transplant and flush hardcore.

[themastermind]

I am already in 3 gallon pots i dont know if I want to go any bigger. Anyhow I dont know if its a good idea to transplant so close to the 12/12 cycle. Even if I were to go to a bigger pot, would there be any advantage?

[khyberkitsune]

I transplant all the time even a few weeks into 12/12 if I see problems. A little stress is good for the bud.

The advantage would be more natural buffers to help keep your pH in a more ideal range. You're looking at wild pH swinging and that is NOT good.

[Rusty Trichome]

I transplant a couple of weeks into 12/12, too. As a matter of fact, the practice is recommended. It helps replenish soil and the soil buffers, gives 'em more root space, and I can adjust perlite to fit the current season/situation. (more perlite equals better drainage)
Likely they have been in the same pot a while, as it takes a couple of months for the soil buffers to deplete. This applies to any major brand of peat-based soil.

Monthly flushes to remove built-up nutrients can help stabilize the ph and remove excess nutrients and micro's.

Mixing soils from different companies is usually a bad idea, as different components can compete/amplify/interract with each other. Often with an undesirable result.

Never re-use soil unless you know what you're doing. (adjustments/ammendments necessary)

How are you calibrating the ph pen?