If you have a properly pH buffered nutrients and chelated micro nutrients, you shouldn't need to add any lime.
Our growers have done 100's of round of peat moss (promix) without the addition of lime. Here is Sour D in promise at week 6 of flowering.....she is fed every 2 days with Perfect Grower nutrients at an EC of about 1.7.
If you're having pH issues, you should consider a different nutrient line or add lime as necessary.
Good luck!
To me this all sounds like a shady sales pitch. First, pro mix isn't straight peat. That's why it's called "mix". It's already pH'd to spec and contains buffers. "Hundreds of rounds without lime"? SO WHAT. Promix is an industry validated horticultural product ANY decent nutrition product will grow superb bud when used with pro mix. That is why it is common for pro growers to simply use peters and pro mix.
Visit tomatoville, tomato masters use promix and compost alone to grow stunning tasty beauties.
The repeated reference to the sour d is a little desperate.
"If you're having pH issues, you should consider a different nutrient line or add lime as necessary." really? that's your response to :"How about lime in say promix? How much is enough?"
Im not sure what you're used to dude but things at riu and IC are a little more rigorous than you seemed to anticipate.