Question about pH flushing.

[horseguts]

The soil I'm using is a combination of Peat Moss, Worm Castings and Perlite. I started Nutes about a week ago, half strength. I've been testing the water I've been using and it's between 7.5 - 8 and the soil run off is around 4.5 - 5. I went and bought a bottle of pH up and added it to a lot of water. The water became a pH of around 9+. I used that water to flush my plant. It's in a 6 litre pot and I ran around 6-7 litres of the 9 pH water through it and let it drain. The pH of the run off at the end was still around 5. How long would flushing normally take to raise soil pH and should I just use water with a 6.5 pH to water with when the plants need it? Would that change the pH of the soil eventually? Within a week or two?

 

[Woomeister]

Cell walls of peat moss bind large amounts of nutrients, much more than the plant needs for its own survival, leaving the nutrient level of the surrounding water barely above that of distilled water. The cell walls function as ion exchangers. They rapidly absorb cations, such as calcium and magnesium supplied by rainwater, and, in exchange, release hydrogen ions into the water. Because hydrogen ions render the water acidic, bog water is almost as sour as undiluted vinegar (pH=3-4). Thus, peat mosses create and maintain a nutrient-poor, acidic environment that fosters their own growth but is intolerable to all but a small variety of highly-specialized other plants. So I would personally use a different medium as you will always have problems with low ph otherwise.

 

[horseguts]

Yeah, that's good to know but the plant is already about a foot tall and in soil so what I need to know is how could I go about raising it?

 

[Woomeister]

you need to repot it...

 

[horseguts]

you need to repot it...

It's in a 6L pot now and I would have to replant 6 L of the current soil into a new soil. Would that even make a difference overall? How about something like adding lime to the soil about a cm under the surface and as I water it, wouldn't the lime seep into the soil?

I'm thinking about cloning it into 2 clones or so and replanting them into "good" soil. That way if this one is beyond repair then I kind of have a "do over". What do you recommend to use as soil?

 

[Woomeister]

Unless your plant is root bound then you can easily shake much of the medium away (I have done this many times for other reasons with no probs) A 6ltr pot is very small anyhow so a bigger pot will be needed, as for soil I live in England so soil types/brands are very different.

 

[horseguts]

Unless your plant is root bound then you can easily shake much of the medium away (I have done this many times for other reasons with no probs) A 6ltr pot is very small anyhow so a bigger pot will be needed, as for soil I live in England so soil types/brands are very different.

Do it while it's dry I guess too eh? How would you replant roots without damaging them though? Also, do you grow in the ground or with a soil mixture? If a mixture, what's it composed of?

Also what about the lime idea?

 

[Woomeister]

Im a Hydro grower, but studied Botany to degree level so understand plant biology and soil etc. Yes do it when its dry, roots wont get damaged if you are gentle, no vigorous shaking and dont use your hands to remove any clumps of perlite. As for the lime idea; by adding lime you are not going to reduce the acidic levels of the peatmoss. Peatmoss cannot be 'diluted' unlike other mediums. It should be emphasized that the pH scale does not indicate the amount of the acid or alkaline properties in the soil, but only the degree to which they are free and available. Usually most marijuana plants make the best growth in a slightly acid soil with reading between 6.0pH and 7pH so the mixture you develop should include: Top soil, sand, potting compost and vermiculite (for aeration) usually a 45% /5%/35%/15% will have a ph of around 6 and has all the requirements of a good growing mixture.

 

[phusionsa]

Yeah, that's good to know but the plant is already about a foot tall and in soil so what I need to know is how could I go about raising it?

A foot tall? feh, transplant it bro!
I transplanted a plant larger than that from MG crap, to Foxfarms. I did not beat the crap out of the rootball too much. But I got rid of as much MG as I could. (also, if you transplant, prep the new soil by watering it down with ph balanced water prior to re-plant, least, it is what I did).
Yeah, the plant freaked out for a week or so, but it settled in and is now begging me to cut it down and smoke it.
I hate beggars, that bitch has to wait.

 

[TechnoMage]

Are you in flower yet? I always repot my plants when going from veg to flower, doesn't harm them a bit.