For very dry MP, does it help to wet it in the soil bin, before filling trays? Is there anything else that would help water absorption and still be organic?
If you have a bale breaker it makes sense to make your own mix. It will be the same amount of work and less expensive. But, most farms don't so Pro-Mix is the best option without a bale breaker. Mixing peat moss, perlite, coir, vermiculite, wetting agent etc isn't practical for most farms without a bale breaker.@@HoustonHardMoneyLoans
To be honest I'm not sure. But I woudl assume pro-mix would've done the testing on that. Also the starter charger has very low ppm numbers so the amount of P would be pretty low