russets are actually so tiny a loupe might not catch them. usually you don't see them until there are literally billions and it is too late. sorta looks like dust moving on the edges of the leaves.
it's a 200 w light which is pretty good for a 2 x 2. it is a bit of an off brand, a second probably couldn't hurt in flower, 2 would be enough for a 3 x 3 probably.
I am pretty sure that a pack of seeds I received one year from Crop King had a colony of russet mites "overwintering" on the seeds. Yes, they can do that, apparently. They were in one of those tiny Ziploc style bags. I placed them into storage. It got *hot* (I know, I know - and I've been paying for it ever since, lol). Some time later, I was trying to get (anything ) to germinate, and I happened to pick up that pack and look at it. It looked as though hundreds (more?) of "micrograins" of dust had spread out from the seeds.
A pair of those lights - assuming they're actually 200-watt units (an inexpensive Kill A Watt device would show the user what a light or anything else plugged into the KAW actually consumes) - would probably be much better suited for a 2'×4' tent than for a 3'×3' one. Both because of the amount of light and because of the shape of its footprint.
OP: I don't like MiracleGro products in general, for a few reasons. But with that product, specifically, my main concern would be its NPK ratio. Someone posted a good nutrient profile for cannabis, and... well... that's not it. If I'm not mistaken, it was @FelipeBlu . Was I correct, Felipe? If so, would you be kind enough to enter the discussion, please?