The promix comes from the factory pH stabilized already. You still need to check that your water isn't going to be a problem. CRAP where is that thing I posted on the shit.
Here!
Sez my main chica FoxySox:
heh heh heh
I've been using ProMix BX lately and the trick to avoiding pH problems is this:
Promix is stabilized at the packaging plant by addition of lime, a pH buffer (CaCO3). The pH of peat, the major component, is naturally around 5ish. The lime keeps the pH up above 6 UNTIL IT IS USED UP. This occurs because when you add water, you are allowing a chemical reaction (neutralization of the acids in the peat by the lime) to take place. Over time, the amount of lime left will drop, and this neutralization stops taking place.
Your job as the soilless ProMix grower is to keep ahead of the pH!
Typically you will start to see problems after about 8 weeks of the plant being in the same pot. This is because the lime is used up and the peat is breaking down into a sludgy peaty acidic swampy mess. pH will plummet.
So how do you avoid this? Simple!
Pot up into a pot that is JUST big enough for your plants. Time your grow so you are potting up into the next size pot, with fresh ProMix, every 5-6 weeks so that new root growth is ALWAYS going into nice fresh soil.
Staying on schedule, you should rarely if ever have to flush to keep your mix at the desireable soilless range which is about 0.4 pH points below the range for soil.
Good luck.
The fungi comes as a powder and you just mix a little into the soil and it grows and spreads around on its own.