I've been growing in promix for many years. pH should be 6.3 growing in. No fertilizer for 2 weeks at least. You should add 1 cup of lime for each cu. ft. of soil. I add worm castings and perlite too. So, for each 3.8 cu. ft. bale I add:
1. 25-30 lbs. of worm castings
2. 4 cups of dolomitic lime
3. 2-3 cups of kelp meal
4. ALOT of perlite- maybe 2 cu. ft. per bale.
If they start to yellow or lighten up, start light fertilization and build upward over time.