I am trying to raise the ph of fox farm 70/30 mix and Fox Farm 50/50 mix. Both of those are for hydro and PHed at 5-8 to 6.2 I’m trying to raise PH for a soil grow. They we’re on sale, just trying to save a buck. Moneys tight , I will also be adding worm casing and compost. I did a slurry test on the compost and it’s high around 7.8.
Im trying to figure out the amount of Lime to add to the mix. Any ideals. ?thanks
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I defer to @Budbrother for making your own soil mix. I haven’t tried this, and I don’t want to steer you wrong.
Lime acts mostly as a buffer to maintain PH, but I wouldn’t add a lot of it. It depends on the volume of soil….
As well as you water ph and hardness you’ll be using.
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Yes going to be hard to judge depending on mix ratios. Worm castings can also up pH, compost that high mixed with the coco probably .5 tablespoon per gallon, but I’d probably mix well, get moist, let sit for a couple days and slurry test. looking forward to Buds response.
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Thanks both of you
Yea I been banging my head with different recipes for awhile now and having results but still not happy with any , and soil tests at 40 a pop is a lot. So much involved.
It’s funny I thought I could trust slurry test for Ph but apparently not. Last batch I made up I was getting 6.8 , I sent some off to get tested and ph came back 6.1 ???
It’s to hot also and probably getting hotter.
Stunted growth
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If BudBrother gets time hopefully he will have some input. Hard to judge lime, basically have to cook the medium for a couple weeks for the lime to do anything. Idk..
Following
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Starting to get some light green leaves on new growth. Might be a problem
Yes letting it cook and I have 0 patients. Not good lol
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Well, unfortunately building a medium does require some patience. There are some short cuts but that’ll negate your seemly organic goals. Perhaps soilless media is your jam, requires almost no patience. 
just a lot of input.
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City water is stopping me
Back to the drawing board
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RO buddy lasts quite a while. I did that and got a $10 55 gal drum. RO always on demand for $85-90 up front.
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Another pro for coco……..
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Thanks it sure would take the guess work out of it. Hydro grow so much so fast it’s almost scary
And I still have jacks from last time I tried it
But these are the girls and they are in my hot soil. Probably could knock a lot of it off if I do the switch soon
I’m always shoot first ask questions later
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Generally speaking lime is an upwards buffer. Hydrated lime goes down with time. You have 5.8-6.2 soil. The compost is fungal dominant with a 7.8. I wouldn’t bother adding a lime agent. This should equalize once mixed to like 6.7-8. You can always add some prilled limestone if you need to go back upwards or for flowering phase.
My recommendation for slurry test is to take sever samples. Then mix them together for avg pH of the pot. Even with a soil pH probe you have to take 3-4 to judge.
Same goes for sending off soil tests. Homogenized used soil together and pay for one test. Then amend per recommendations.
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Thanks for the info. I didn’t understand why the 2 different Ph from the soil. My slurry test , after I amended and mixed in everything but the kitchen sink in it I took some out and bagged it up and did the slurry from the same sample I sent in and got 2 different results. I’m guessing maybe they are both off since I never gave the organic amendments I put in time to dissolve or break down.
How much lime would be a good start per gallon of soil ?
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Many variables, why the pH changed. Soil dried out pH dropped is my guess. Depending on what amendments were used the microbial or biodegration processes is another.
I don’t use dolomite, so I don’t know application rates for it specifically.
Limestone starts 1 tsp/gal in general. I do 1/4 cup/cft so that comes out to just under a tsp.
Edit: why no dolomite? Because improper Ca to Mg levels
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I wasn’t aware of the ratio of the two making a difference. Down to earth has 2 different limes I picked the dolomitic instead of the garden lime I thought why not calcium and magnesium 2 in 1 , why not
Thanks for the info
I’m going to simplify my mix next time and forget about the super soils.
It’s always about ratios and I’m just guessing when it comes to it
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I get mine in 40# bags from Rural King for $10. That plus gypsum, for Ca without pH adjustments.
Simplify your re amend process. Add a balanced 4-4-4 premix. Add a mineral mix of gypsum, limestone and Azomite. Cook 3 wks.
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I grow on the cheap with Dr Earth 4-4-4 & 3-9-4 plus above.
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Do you add any worm castings or compost
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I use Bu’s Blend biodynamic compost and make my own EWC and garden compost for diversity.
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