Quote Originally Posted by Rusty Trichome
Doubtful your ph numbers are accurate. FFOF is properly buffered near 6.5 to 7.0 ph, I believe. That's where it should stay for a couple of months till the buffers fade.

What are you using to check runoff ph? If it's a color-coded result, (freshwater aquarium ph test kit, ph test strips...) the tinting of the runoff will skew results.

If using a ph pen, it likely needs calibrating.

Or, you are re-using soil.

Or, they forgot the buffers in that one bag of mix.
I guarantee that pH is correct. I have an Oakton pH pen that I calibrated before and checked after. It was dead on! I also confirmed with a ph test strip. The ph numbers are accurate unfortunately! I did notice the nitrates were off the charts! Total hardness looked about 400 ppm.

I thought the same thing... They forgot the buffers in this bag! Who knows. I've heard others say they had low ph (5.0) runoff from FFOF too, with little problems. I think FFOF is over-rated! I'll use something else next time. I even added my own buffers (albeit a very small dose, 5-6 tablespoons per bag of FFOF.

The fact that redtails was unable to save a ph-skewed plant scares me. Is it too late to sprinkle some dolomite lime on the surface and hope it will infiltrate the soil?