Leaves curling up

Thanks everyone, I've added my diary onto here now so if anybody is kind enough to read and let m know where I could be going wrong I would greatly appreciate it. It can't be from spraying the leaves as I don't do this, and as most of you have said my temps and light seems unlikely but I can't think of anything else.

I had this problem when I spray the leaves during the day. the drops create a magnifying glass on the leaves which is bad when the light is on. if you do this, you have to spray the leaves at night

I am with @Growstick on this. It is hard to help you without a diary. I don't think it's too much light. TS 3000 is using the Samsung LM301B or similar diodes, so 27 inches dimmed at half intensity is not going to fry the plants. If nothing else, you need to be increasing light depending in your feeding regiment (diary).

how's it going pal it sounds like your light may be too intense, I would either raise my light about 6 inch from top of canopy and keep at 50% if that's not an option I would lower the power by around 10 to 15% and keep an eye on them over the next few days to make sure the problem is not getting any worse, if they don't continue to curl anymore then your problem is solved just remember to raise your lights as the plants grow, there's also a good light meter app you should check out the photone app, hope this helps good luck

Yeah, so then easy to assume it's the easier of the issues. Raising the light or increasing airflow will remedy this.

Forgot to mention pH so far has varied from 6.06 to 6.4

Thanks, I've been keeping a personal diary unfortunately just not on here, ppms at 5-600 using AN sensi a&b coco at 12ml, voodo juice at 20ml (stopped now), nirvana at 12ml, b52 at 12ml and botanicare cal mag at 12ml, all for a 10 litre mix. Watering every other day until I see 20% or more run off, they're in 3.8 litre fabric pots. I googled canooing and yes it looks exactly like that only it's just started and other than that the plants look beautiful, no signs of discolour or other signs of stress. Will try upload a pic tomorrow if I can

Well, if it's a canoe shape then yes it would be heat stress this can be mitigated via more air flow or raising the height of the light, of the tip is curling up most likely a deficiency or even pests? As Growstick pointed out however is without a diary it's a guess at best.

Hard to give you any advice without a grow diary. Sounds like it could over watering from your short description. Lights would be too far and too low to cause light burn surely(?). Could also be nute burn, but we don't know what you're using and have no pictures. Temps sound a bit low - try to raise it a few degrees - but I doubt it would cause leaf curl. Good luck!