More perlite=more feeds per day, which =faster growth. I use about 80-90% perlite. I just ran a side by side experiment of a plant being watered 8 times a day versus one that was hand watered the same amount but only 2 times a day. The hand watered one was also under a 1000 watt and the other only 600W. In 1 week from transplant the hand watered one was half the size. After 2 weeks it wasnt even close, the hand watered one was less than half the size, a foot tall at the most, while the others were about 2.5 feet. I had to put it back on the auto water because it was just being completely overgrown by the other plants. I have run 8x feed per day in 100% coco, but i found this only brought problems as it holds much more salt and if you get a clogged dripper and your medium drys out your basically kissing that plant goodbye, as when you unclog the dripper and the medium resaturates you will get extreme nute burn. High perlite ratio is very forgiving and if it drys out theres much, much less salt waiting to be absorbed. Ive read tons of hydro threads, uc, mpb and honestly I believe I get very close to the same speed of growth in this mix with 8 feeds a day.