I have 40 lbs of eco complete in my tank as well. Did not rinse per instructions. Tank was/is fine. If u rinse it you're rinsing out the nutrients and beneficial bacteria that makes EC different than plain gravel.
Eco complete does not have nutrients it's mainly lava rock. What makes it different from regular gravel is the fact that it's inert, which means it has the ability to absorb nutrients.
I have 80lbs in my 72 no rinsing, it was fine. However I do suggest using root tabs with ec