First Legit Grow

You're off to a good start. I'd say you've avoided the worst mistakes newbies generally make and you're well on your way to growing some truly impressive plants.

The advice here is all good. I agree that some clones from the lower branches are a good idea. You're not going to get good light penetration down there so the plants are basically wasting energy growing those branches. If you lop them off near the stem you'll have some excellent cuttings for clones and your plants will be free to concentrate their energy on the parts that will grow you nice buds.

You're using one of my favorite nutrients and you're not overdoing it. Kudos for that, I see too many newbs buying a dozen bottles of stuff thinking that's the key to growing massive plants.

I would also recommend doing some LST.

As far as light height goes, put your hand at the same level as the top of the plants, palm down. If the light feels like it's burning your hand, it's too close. Otherwise you can consider lowering it. Just keep an eye on your temps too. And for the first day after lowering it watch your plants carefully for signs of heat stress. Getting enough light is critical to getting good growth, but like with your nutes it doesn't take very much of "too much" to really screw things up so be careful.

those plants are gonna get fukn huge hahah they grow 2-3 times for flower, dive into the topping and lst and other methods to tame those wild beasts! they look great though man. your gonna have a nice yield even if u trim those girls down. by cutting off a portion of the plant the energy that would have been used for that weak low branch is not lost just sent to the colas above to make em even tighter. good luck man!