Ah, I see what you mean about people noticing. Colombo is a busy place! As far as the tent and grow light, that's a great idea if the weather isn't so good at the moment.
The mix the farmer has supplied you with has a higher PK ratio as opposed to the N. This means this fertilizer is best used when the girls are flowering. It's best to get something with a higher N ration and lower PK for their vegetation period. You're in coco, which I think is a good idea considering where you are in the world it would be cheap to buy.
Don't stress too much about how much nutrients you use, focus on how little you can get away with. The girls WILL tell you when they want something. The most common thing you'll find is purple stems - lack of cal-mag. This is not that bad a deficiency to have. Use the kelp (seaweed extract) at standard strength. It helps a lot of deficiencies. You can also dissolve some epsom salts in your water (I use about a tbsp per 10L) which will sort any magnesium issues as well.
I keep my girls pretty dry. I record everything so I know how to resolve any issues I may have previously had too. I only feed them once a week, with a watering in between, but they are drinking more now that they're nearing the end.