Droopy plants

Ph is the perfect one for soil medium but fairly too high for a hydroponic grow : 5.8 is the sweet spot. Humidity is too low so the air is too "dry" and the plant can be stress. Your day temp is near to the good one to kill a cannabis plant as 10 °C will only lead to a budding "attempt" without something correct to smoke in final so try to find a heater to raise the temps to 10°C higher than actually ( 20°C at least). Check your nutrient schedule : is that normal to give more bloom than veg nitrients while in vegetative stage ?

Looks like a lockout.

I'd love to provide correct and concise information to this whole mess. But you have not filled your Diary out correctly, I know it can be tricky to do at first. I mean start with the basics, make sure the air pump is bubbling up the reservoirs, then flush, dump and change and reservoirs. 10 Celsius can't be right. 35% RH doesn't sound right either. Do you have a Temperature and RH measuring device. Umm I hate to just repeat others advice but... growweedeasy.com is a great a place to start.

Hey! You should check: 1. PH level: for DWC/Soiless growing recommended PH levels are 5.5-.6.3. 5.5 at the start of growing and you can PH up by weeks, on flowering you should have PH levels around 6 (because you will suffer P/K problems if not). 2.Check the temp: 10C is a very low temp since they stop growing below 18C. You can reduce your air intake or maybe, take the air from a warmer place during plants "nights". You can also use warming wires. 3. Check your solution temp: DWC water deposit temperature should be between 20-22°C. That's the perfect spot between a good oxygenation and nutrient absorbing capacity. If you check and solve that points you could restore them back!

@Catsmeow Looking at the temps and humidity you listed I would say that had a big part in why your plants look so miserable 10 degrees is pretty cold for a plant and 35% humidity is too dry . As far as the ph issue goes when your plants are stressed they tend to only take up the water leaving behind the nutes (salts) which makes the solution ph rise. ******* Solution don't stress your plants too much ***get a heater if you have to to keep temps around 18 lights off ****** mist with water to raise humidity or put a damp towel inside the grow area. Hope to have helped mate

Check the air pump and line. They look like they lack oxygen. Perhaps you had a blackout for a few hours?

ph 8 somehow?...… I thinkm that is answer enough , to explain why the plants look so bad. Your Goal is a ph between 5 and 6 in dwc. more in the comments

If your ppm is truly 110, you'll need to add some nutrients into the water. That is very low, they will recover but you need to act soon with the nutrients.