My experience with FFOF is it is alkaline, I feed inbound at 6.0 and get a runoff of about 7.0-7.1 on fresh soil tho over time that wears down.

I try to keep inbound between 6.0-6.5 and haven't really had any problems.


That is until recently when my Pen got out of calibration and I started PHing inbound to 5.5 and less! (Didn't know it because the pen was whacked)

Now I'm still suffering the effects of it, even tho my inbound is in line again.

Inbound of 6.0, Outbound of 7.1 is a soil average of 6.55...... that's pretty f'n close in my book! :jointsmile: