Do i have N tox???

This is my first time really growing I've posted multiple times on here for different things and I seem to be struggling and not getting very far right now I've got one plant coming back into a good growth spurt from all the leaves turning yellow and now I've got a second plant starting to curl I think I'm starting to have some nitrogen toxicity there anyone out there that can tell me what to do to make this better I'm using Sensi grow a + b on a 18 and 6 cycle at 500 watts or is it too late to help this plant because I'm fixing to switch it over to flower and another week I watered yesterday I'm going to hold off on watering until Monday and give it for good days three good days scuse me today is Friday to see if that helps

Looks fine to me.

Some of my leaves are canoeing and curling under ? I water to much u to? Need to figure it out 1 week left before flower start. 15th is my start date

Looks like a bit of heat stress made worse by too much air flow on the leaves. Aim your fan to a wall so the air isn't directly blowing on the plants but it can circulate around the tent.

I hope you can raise your light more as they are going to grow right into it when you flip to 12/12. They look like prime stretchers to me. I'd be flopping tops over or even chopping 6" off the tall branches first.

When you water do you soak the pots good then let them dry out until they feel light before soaking again? Never get overwatering problems when done like that.

I found a great spot to download FREE POT BOOKS . I downloaded a grow bible first and got lots more. Books look great and complete like the real ones I have here. No web site but just a page of links. Just right click on what you want and then "Save Link As" to download so they don't open first as many are 50+ megs. They got lots. Enjoy.

water and cal mag for a week?

Not sure I need to ph test and not sure what to do about cal mag I haven't really read about cause I don't know what to try to fix what is wrong

Can i super crop the tops to keep them more away from the light I have run out of room I think .? Or would it hurt since I'm waiting a couple more days to switch it over

You can definitely supercrop them still.