media Peat - is Lime really required?

Hi guys,

I'm preparing to move my peppers into larger pots, and I'm in the process of preparing my soil. I've found several posts here where it's stated that a 7/2/1 parts peat/coco, perlite and worm castings would do great when fed with CNS-17. I did that last year with coco and had great results. However, this year I have a big bag of peat moss left over from filling some raised beds and decided to use that instead of coco. Now, after I prepared a batch I found other posts that recommend adding Lime since peat is acidic.

How have you guys done it? I have the Lime already to improve the PH, just wondering if people have had success without using it given the above 7/2/1 soil mix mentioned above when used in conjunction with CNS-17. If you have used it - how much did you add?
Lots of variables here. Only way to know for sure is to first measure the ph of your ingredients.
Peat usually ranges between 3 and 4,5 depending on the type and origin of your peat.
The coco and wormcastings also have their specific values. So not an easy formula without measuring!
To raise the ph by 1 you need to mix in around 2 kg of lime per 1000 liters (2 grams per liter)
Also take into account that your mix needs a few weeks to stabilize and values can alter in that period.
So measure your startingmix and monitor it a few times afterwards.
Thanks, lots of conflicting info online, and the vendor (Aurora Peat) does not list this information in their page. Here's what I'll do - I'll take a sample of the mix and let it steep in a double cup. I'll measure the Ph afterwards to see if it needs any additives.

To clarify, I'm using CCanadian Sphagnum Peat Moss (
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That looks like basic peatmoss so ph will be 3 to 4,5, normaly that would take 5 to 6 grams of lime per liter to make it neutral. Worm castings are generaly quite alkaline (above 7) and thus will alter the ph of the end product.
For peppers it's best to aim around 6. You could make some small samples ranging from 3 to 5 grams of lime and measure the ph after a couple of weeks.
I don't use lime. Instead of it I use biochar. Mixing 13-16% charcoal to the peat. One part biochar and 5-6 parts of peat. Works for me 🙂 and a bit of worm castings and dry fertilizer.

Like @Sulsa said worm casting PH is around 6-7.5.
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