Curled and spots on leaves - hos to fix?

Maybe the humidity is to dry making her tips dry out

This is burning due to excess nitrogen/too much fertilizers............over feeding basically..............nothing more, nothing less.. Dwarf/baby plants need baby feeding. Your pots are too small too. This will cause salt build up quite rapidly, especially if you are not watering to get proper run off each and every time. Plants growing in quality, decent soil should not need fertilizing for roughly 4 weeks and then only with half strength to start with.

If I can guess I would say its ph related which is blocking the plants availability to absorb the feeds you are giving Magnesium deficiency is what I can see but if it is a ph lockout then it may also start to show other issues unless rectified

If you sprayed the leaves then that could be the problem. If you didn't then its something else.

When the leaves curl inwards, usually the plants want to loose less water. It's hot in Europe right now and with 27°C, 50% humidity is too low. Your fan mostly hits your bluezkittlez, try positioning it further away so the dwarfs do not only get hit when it turns to them. This can be related to your decolorisation, but like others i'd add calmag too. For RH try wet toewels, they will dry out over the day.

So. At this stage. Ur RH is pretty slow. Which is making the plant draw more on your sub. So, i don't know your PH. Its a mag issue but I don't think its a lack of in the plant rather it looks like its PH related. Theze nutes give a PH of around 6 and I see twists at the edges making be believe its more PH related. So mag is showing as that's what's not been taken up. So, here's a simple quick fix until u fix soils ph. Add 150ppm of Epsom Salt to your water amount. (If u don't have meters I suggest you even get a basic Demeter 30$ off amazon) but until then add a pinch to 1l of water. Lower your Lights and apply it as a foliar spray. PH doesn't matter and the plant will take it in. Epsom Salt is THE BEST source of mag/sulphur to a plant. And will be much quicker to get as all shops that sell soaps & such will have it. If not a local pharmacy will have it. (Make sure you get a fragrent free "no lavenders or aloe Vera just natural ES) After the leafs soak it up then you can up your light. 1-2x a week. When you can PH. 5.5-8 with coco 6.3-8 for soil. But you can apply it as a foliar spray until u can figure out ph'in i can see the twisted edges so it defo stems from

How much do you feed them? What is EC of the solution?