FFOF users...how much perlite do YOU add?

I was running FFOF with 20-25% Perlite for a while. A couple months ago I changed to a local shops potting Mix and I added the same mix of Perlite.
Bad idea, the potting mix sucks. EVERY plant I have started is severely stunted and starting to die.
I just went through and transplanted all of the stunted plants back to FFOF/20-25% perlite.

It just got me wondering what % that YOU guys add to your FFOF.
With my past FFOF grows, I had to water about once a week. I'd like it if my soil would drain better. Could I go up to 50% Perlite when I transplant into my final 1.7 gallon pots?

i use about the same as you, around 25% or so'ish.. i'm sure you could cut it back more, but you'd be watering way more imo..

That's my deal. I want to water more than once a week. Maybe I'll just add a little extra when I transplant.
How much is TOO much?

Yeah, but has anyone on here actually tried it? How often do you need to water? Same nute mix as soil, or would it be different since it's only half soil?