Indoor Runoff/ ph

[PoopsMcDoogle]

okay.. i have heard that the runoff ph should be 0.1-0.2 lower from the actual ph of the soil. i have also heard that it should be 3/4 to a full point lower. which is right?? that is a pretty big difference. another thing. i am going to test a cup full of medium before i plant my next grow. what do you ph the water at to to be tested?? do you ph it at a perfecctly neutral 7? or do you ph it at what you would normally water with and what you would want your soil ph to be at (let's say 6.3)? how do i get an idea of what correct ph to use? let's say for example my soil ph is 5.0 and i wanted to get it to 6.0. should i ph the water to 7.0 and they'll meet in the middle at 6.0?? or ph the water at 6.0 and the soil will then turn 6.0??

 

[stocious]

i asked exact question before and got no answer. so im in on this i need to know how to raised the ph of soil mid grow ect.. also

 

[ACV]

I dont think run off water should test lower than the pH range needed. Run off should test where you want your pH. I dont know about adjusting pH.

 

[bgrt]

hey i asked something similar a week or two ago and this is what i was told, might not answer all your questions but might help...

I test runoff by pHing my solution to something middle of the road like 6.5. Then I water until I get drops coming out of the drainage holes, and I collect that fluid and test it. I think the first drops are most accurate as they show you exactly what affect the soil has on the water, but the more that comes out you're going to naturally see it drift towards the same pH as the water coming in. I use a small pitcher and I know roughly how much each pot takes before it starts draining, so it's pretty easy to do all this. If I watered with 6.5 and my runoff was 6.3, I'd figure that my soil pH is somewhere around 6.2. So the next time if I want to bring that up I may water with 6.7 until my runoff comes up to exactly where I want it. It'll move around some depending on the plant and what stage of growth it's in, but you can keep it within range fairly easily with some practice.

Originally Posted by bgrt
thanks andy illl give that a shot later on and look for some storage solution i just couldnt find it on the site i got everything else from.. also im going to transplant, how would you work out the soilmix's ph beforehand.
just drench everything to get a huge amount of runoff(ill need about 18 gallons made up)? or is there a simpler way, taking a small sample and judging runoff on that etc, just seems like that might not be an accurate way and is all i can think of.

My usual procedure is to fill a pot with soil and drench it with a pHed myco solution a couple of days before planting. I test and record that runoff since it will likely vary between pots unless everything was mixed perfectly. And if you find that the soil is way off you can add lime or take other action before you have a seedling in the medium.

You can test soil by making a slurry with some distilled water, but like you said, that's such a small sample size that I don't think it's reliable.

also was told to look here anyway.
http://www.growery.org/3072/Managing-PH-with-your-Cannabis-grow

about using 7 to get to a midpoint from 5, i think you are prettymuch right but ph is on an exponential scale so 6 is 10 times more acidic than 5 so im not sure if that has to be factored in as i only started ph'ing myself last week but it might play a part.

https://www.autoflower.org/f2/ph-control-info-8016.html this was the thread just incase i missed anything important.

good name btw

 

[The Squid]

Hey man. bgrt has given some very useful information from Andy Botwin. It also depends on what kind of medium you're using. Hydro is around 5.8, semi-soilless like Promix is good around 6.2-6.4 and soil is good at around 6.4-6.6. You can use lime to raise your ph and sulfur to lower it. Like Andy said, make sure it is spot on before you even plant your beans in and it will save you some headaches.

Here is an awesome ph chart that I like.>>>

 

[Eschatos]

The ideal situation is to adjust the soil's ph to where you want it to be. To raise it you can use dolomite lime, bone meal etc. To lower it you can use sulfur or organic matter, like compost, wood chips, peat moss etc. Once you've done that, and taking for granted that you ph your feedings to the same ph, you just check run-off water every now and then to make sure the soil's ph doesn't change over time. If it does you fix it again

To try to hit the ph you want with waterings, like you said soil 5ph + watering 7ph to hit ~6ph, is a temporary solution if you need to water you plants before you fix your soil, if a solution at all.

 

[stashmouth]

All good stuff. Bookmarking for later.
Thanks guys.

 

[PoopsMcDoogle]

thanks a lot, friends.

 

[PoopsMcDoogle]

ahh. i think you are right about the exponential scale thing having to be factored in. andybotwin said that if his soil ph was at 6.2, he'd water with 6.7 to get where he wants it (i'm guessing 6.5). so im guessing you can subtract the 0.2 from the 0.7 to get the 6.5 you need. but i think this math only works within that one point range. (6ph-7ph). so, i don't think my theory of getting a 5.0 to a 6.0 by adding 7.0 would work. i think it would have to be a lot higher than 7.0. 8.0 maybe? or was 7.0 right? 5.0 would be 10x more acidic than 6.0 and 100x more than 7.0 and 1000x more than 8.0 and so on. i know that if ph is off too bad to just lime it or whatever but this math is good to know. i'm going to bed, as i am too tired to think right now. i think we're on the right track though.