How much ewc and perlite do I add ? RG tupur

Im going to be adding the ewc and perlite to royal gold tupur and amending with dr. Earth

How much ewc should I add per gallon of soil? I think buildasoil suggested 5-10 % of the total volume of mix .. what do y’all think?
& for perlite should I do an equal part? ,
1 part perlite : 1 part mix ?

Usually I do it by feel on the perlite but I think I added bit too much last time

Are you following a recipie or guessing as you go ? Think ya need to read bronor you will fail hard and wonder why

None. I've used Royla Gold Tupar(Orange bag, not to be confused with the Red bag of Coco) and NEVER added anything including extra perlite. Don't over complicate things.