hey kitty, just had a wee catch up there.
that light is about 150w . the space is roughly 3 square feet so thats right on the max power point for blurples of 50w/per sq ft. thats a lot of light for such a small space so temps will be a bit of a pain. you dont have to keep temps and humidity perfect, just relative to eachother. its called vapor pressure deficit 'vpd'. a quick google of
'vpd scale' will sort you out. if you find your struggling with heat then you can take steps to make your humidity level more suited to cope with the heat. wich in turn will help with growth. i seen you doing some defol aswell. i chop bag fulls off mine every week and its never done any harm. i grow xxl plants though so theyre a bit tougher than most. personally id be chopping a few big ones off her every other day about now to open her up. get as much light in as you can while shes stretching.
regarding your ppm, 750 is about right to be putting in at this point. id leave it there unless you start getting deficiencies then up it about 20%.
can switch to bloom nutes whenever you want really but she's gonna go mental on you shortly so i wouldnt wait too long if your struggling for space : )