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soil Thoughts on my soil mix

40% peat moss
20% mushroom compost 
20% black kow manure
20% perlite
2 tbsp dolomite lime/gallon of mixed soil
 
Does that seem about right? I just bought everything I need. Originally it was 1/3 peat moss 1/3 compost 1/3 perlite, but then I figured I probably don't need that much perlite, and I could mix manure and compost together to get a nice variety of nutrients. I've looked around and the consensus seems to be 2tbsp of powdered dolomite lime/gallon of mixture, since you want to raise the pH that was lowered by the peat moss. I'm making enough for five 5 gallon buckets that will go in my grow tent. So I'll mix all the dry stuff on a tarp and keep track of how much volume there is, mix the appropriate amount of lime in, then fill the containers and give them all a good thorough watering? Should I let them sit for some days before I transplant my plants (they're in 1-3gal) to let the lime have effect?
 
Really I'm just nervous about screwing it up haha. Just want validation that nothing's too wrong with my plan. Thanks
 
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sibed said:
I've looked around and the consensus seems to be 2tbsp of powdered dolomite lime/gallon of mixture, since you want to raise the pH that was lowered by the peat moss. I'm making enough for five 5 gallon buckets that will go in my grow tent. So I'll mix all the dry stuff on a tarp and keep track of how much volume there is, mix the appropriate amount of lime in, then fill the containers and give them all a good thorough watering?
 
 

Are you sure that was dolomite lime? That's the only part I would question with your mix, your magnesium levels and magnesium to calcium ratio. Not saying it's wrong and you probably know what you're doing, just saying that's what I'd double check.
 
danish said:
 
Are you sure that was dolomite lime? That's the only part I would question with your mix, your magnesium levels and magnesium to calcium ratio. Not saying it's wrong and you probably know what you're doing, just saying that's what I'd double check.
Yep. Here are some posts I've found from, uh, other forums, all in the context of dolomite lime.
 
I would think at most 1 1/3 tablespoon per gallon of peatmoss. 10 pounds per 27 cubic feet or 1 yard max lime rate. .13 cubic feet in a gallon .13/27 x (10 pounds x 12 fluid ounces per pound x 2 tablespoons) = 1.16 tablespoons. If your fertilizer is highly acidic you might need this much lime. If your ferts are more alkaline you would use much less. Adjusting your fert water with an acid or base and adding calcium and magnesium makes liming less important. Better to underlime than add too much. PH is good at 5.6 to 6.2 in soilless grows so this is sort of low.
 
Powdered dolomite lime should always be added at the rate of 2 tbs/gal of mix. Whether the mix is pure peat or peat/perlite/wc/whale shit and boat anchors. The dolomite has to be in that concentration to provide calcium and magnesium.
 
You should always use 2 tbls per gallon unless you are using FF or something with lime already added. The FF OF I use has crushed oyster shells to control the PH. I add one tbls per gallon and my PH sits a 7. Lower your water PH to 6.0 and everything should be fine. If theres not lime in your base mix add the 2 tbls. per gallon.
 
2tbl/gallon of mix or, 1cup/cf of mix.
 
One cup per cubic foot of growing medium.
 
Yes, 2tbl/gallon of mix for the lime.
 
 
I've since made the potting mix other than adding the lime, since I ran out of daylight last night. I think I'm gonna do 10tbsp/5 gallon bucket-full.
 
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