Sometimes I won't pre-rinse but I will make sure I get a good bit of run off on the initial watering/feeding
I've probably bought 20 bonticare 5kg bricks in the last 2 years and I've never rinsed.
I got some sunleaves brand one time and even rinsed it (not enough) and saw all kinds of problems with it.....plants had to be trashed.
But Bonticare is pre rinsed.
There was a very noticable difference in results.
Actually I read that the ready mixed bags are pre charged and the bricks are not...The better brands of coco, including botanicare bags and bricks, are pre-charged with nutes to avoid the common initial deficiencies of cal and mag. Flushing the coco just means that you have to recharge it yourself.
Actually I read that the ready mixed bags are pre charged and the bricks are not...
I think a lot of us take it for granite that better coco is pre rinsed but, probably a good idea to test the ppm etc befoe using...
ultimately its on the grower all the time to know what they are dealing with. and information varies for products widely. I prefer to do my own prerinse and charge it with my known use of nutes. less mistakes if i start from 1st base.^^^^FH