Foglie arricciate verso il basso. Temperatura 25° Umidità 45%

you have Nitrogen toxicity going on, Reduce the amount of nitrogen that is being fed to the plants. If you are feeding extra nutrients, cut down that amount. If you are in the flowering / budding stage, make sure you’re using a formula that’s specifically meant for flowering, or else it could have too much nitrogen. If you are not feeding extra nutrients, you may have “hot” soil that has been giving your plants extra nutrients. In that case, flush your plants with filtered, pH’ed water to help clear out the extra nitrogen. Effected leaves likely won’t recover, but you should see the problem halt with no new leaves being affected.