could someone explain what lime (ph conditioner) does

why do people put ph conditioners like lime in soils? i've never understood what the advantage is. i'm using promix hp and it has lime in it which i think is giving me all my ph troubles because maybe i am adjusting the ph wrong or something. could someone help me here?

To adjust pH levels. Some people have shitty city tap water that runs 8+ (Champaign...sigh)

Any soil with sphagmum peat moss as the major component REQUIRES lime to buffer the soil to the correct PH (ie. PH of around 6.0). Peat moss is organic and constantly breaks down releasing acids in the process, so it tends to have a rather low PH by itself (PH of around 4.0). So if you used a peat based soil mix without lime, you'd be growing in a medium with a PH of 4.0, which would provide very poor growth for most all plants with the exception of acid-loving plants (not cannabis). This is why almost all commercial soil mixes contain calcitic and/or dolomitic limestone (the former provides calcium, while the latter provides both calcium and magnesium). Some people add more of their own lime to the soil in addition to what already in the soil from the manufacturer, this is to provide a buffer over a longer period of time, but too much will toxify the soil (like too much of anything).

I'm afraid your problems have nothing to do with the lime in the soil nor the PH of your water. Water PH has very little effect in buffered soil, that's the whole point of a buffer, whatever the PH of the water you're adding, be it 5.6 or 8.2, it will be buffered by the soil mix to around 6.0. Of course, it doesn't hurt to PH your water to around 6.3 just to keep things in balance. Maybe you could post a picture to make your problem more clear.

thanks highpsi that is the kind of answer i was waiting for. so if want the ph at 6.3, so as too not get any lockout, but the runoff is at 6.0 it's all good? i won't get lockout at 6.0? could too much nutes cause my problem? i wish i didn't go rafting w/ my camera or else i would put up a pic. every grow and every plant eventually show the same signs: stretching (under 400w mh) during veg, yellowing in new growth along w/ small, wrinkly leaves in veg and flower, now leaves are folding into almost a tube shape (like their too thin), and of coarse wild ph swings.

badness said:

thanks highpsi that is the kind of answer i was waiting for. so if want the ph at 6.3, so as too not get any lockout, but the runoff is at 6.0 it's all good? i won't get lockout at 6.0? could too much nutes cause my problem? i wish i didn't go rafting w/ my camera or else i would put up a pic. every grow and every plant eventually show the same signs: stretching (under 400w mh) during veg, yellowing in new growth along w/ small, wrinkly leaves in veg and flower, now leaves are folding into almost a tube shape (like their too thin), and of coarse wild ph swings.

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I've never grown anything except tomatoes with a PH as low as 6.

7 is neutral. 6.7 - 7 is good for soil, but most hydro growers apparently like a lower PH, unless the specific strain likes a higher PH.

Lime adds calcium as well.

This from the Beginner's Guide to Growing Marijuana


Soil:
1. It should drain well. That is, it should have some sand in it and also some sponge rock or pearlite.
2. The ph should be between 6.5 and 7.5 since marijuana does not do well in acidic soil. High acidity in soil encourages the plant to be predominantly male, an undesirable trait.
3. The soil should also contain humus for retaining moisture and nutrients.

Maybe this is 1 reason we see so much hermaphroditism on RUI?

Confucius say: If more people would read-up, before asking for anonymous advise, they might save themselves a lot of headaches in the future

thanks highpsi that is the kind of answer i was waiting for.

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No problem. Glad I could help.

so if want the ph at 6.3, so as too not get any lockout, but the runoff is at 6.0 it's all good?

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Yeah.. I think you're focusing too much on the PH. Just make sure your feed solution and your water are PH balanced to around 6.5 to 7.0, I wouldn't worry so much about the runoff PH.

could too much nutes cause my problem?

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I suspect that this is your problem.

i wish i didn't go rafting w/ my camera or else i would put up a pic. every grow and every plant eventually show the same signs: stretching (under 400w mh) during veg, yellowing in new growth along w/ small, wrinkly leaves in veg and flower, now leaves are folding into almost a tube shape (like their too thin), and of coarse wild ph swings.

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It sounds like you're over feeding, which will cause the symptoms you are describing and the wild PH swings. If, like you say, every one of your grows goes the same way, try something different. For example, take 3 plants in the same medium and in the same sized pots, give one plain water, give another 1/2 strength fert., and give the last full strength. See which one does better. I know it's time consuming and experimental, but sometimes that's what needs to be done to be successfull at growing. Remember: MOST PEOPLE TEND TO OVER FEED and/or OVER WATER. I'd venture to say that 90% of unsuccessful grows have this in common. So keep this in mind when you start to have troubles.