Millsie
Well-Known Member
Well yes, and no.PPFD goes up the closer you get, and your plants will tell you when it's too much. You already know the 1825 is going to output more than a 3590, and somewhere between 30-60cm will be fine depending on your optics and garden. Maybe higher if you really crank them or use narrow optics. Lots of variables, easy to figure out in practice.
No need to sweat stuff this small.
Independent third party product test data performed by someone that has expensive testing equipment is absolutely invaluable and only needs to be calculated once. If put on the internet it will last forever, for all to see
However I do understand that time is precious though