In veg, they can take a lot and come back. May get some delay in growth, but most times they can be saved. In your case, I do not know what is causing the curling. What was the last thing you did to them before they started curling? As long as you don't over dose nutrients. Water when dry. Pick up your pots to check weight. As a human you are curious and you will experiment with your feeding style(less is more). keep your ph between 6.0-7.0(6.5 optimal). Keep temperature between °70-°80 degrees, humidity between %40-%70. Consistent light schedule. You're indoors and won't need to worry about bugs too much, but always have an eye out. That's basically all you need.
1. I think i bumped the nutes up to 1/2 strength a bit early. that definitely burned some lower tips and probably helped with the curl.
2. after doing some reading and being a little more educated on coco, I am going to mix up some more 1/4 strength nutes and feed daily for 5 days to see what kind of difference it will make. I am starting to believe that waiting til dry is the wrong approach on coco.
3. lights have been consistent 24/0 with the t8 and then switched to the Viparspectra 300w. The last 3 nights I have switched them off for about 5 hours to let them rest a little. haven't noticed any difference good or bad so I'll probably continue that until I switch to flower.
4. temps and humidity have all been in those ranges almost completely. if it got a little higher, it was only for an hour or so.
5. as far as bugs, I have seen a few gnats or something similar in the house and occasionally around the plants. nothing more than normal though. we live in the sticks and they seem to follow you right in the house.
I did get some yellow sticky traps that go on sticks though as a preventative measure.