Curling leaves - sorry to be a pain!

Hi guys, so my leaves are starting to curl upwards towards the light, which is such a pisser cos the girls are just starting to look really good, and normally I'd trawl the internet before asking but I have to go to work so I was hoping you nice people could help me out as I'm gonna spend all day worrying before I can get home and hit Google.
They're in coco, came to me a week ago and I've very little clue what I'm actually doing but I'm reading and learning a lot.
My journal is here, if anyone's interested, not that there's much in it yet:
https://www.rollitup.org/t/most-disorganised-last-minute-grow-ever.899427/

Whats your temps/rh? Whats the feeding schedule/ppm? These are some of the basic things you will need to monitor to keep issues in check.
As for the curling up of just the serrated tips imo sounds like the start a humidity issue. I'm going to guess its low (anything under 45 IMO is low). I would keep my temps about 75*F and RH (Relative Humidity) about 55-60% during veg. Only feed when the pot feels light. After a few waterings you will be able to tell when the dirt is dry and needs water just by the weight alone. She'll tell you when shes thirsty. I would invest in some nutes and mix up your own mix so you know what you are giving them vs the "mystery mix" jug you got from your friend. The plants look healthy overall but I believe factors in your grow environment will affect them negatively if some of the basic things mentioned are not addressed.

They look fine so far. No worries.

I don't have a thermometer in there but they're in the airing cupboard with the hit water pipe, so it's slightly warmer most of the time than average room temperature. I don't even know how to check the humidity, but I'd guess it's low. I have been hanging damp towels over the hot pipes to boost it a bit but to be honest, until they go in a tent and I've got more control, the environment certainly isn't what I'd have wanted for them at this point. I'm just hoping that I'm not doing too much damage at this point that I'll regret later. I'm considering this my practise run, learning the basics, getting the equipment together and figuring it all out then next time I'm gonna smash it!