Saryis

Please help! What are the white spots on the leaves?

Thanks so much for the help guys! Amazing community here :) I've never even thought about solution temperature- so I'll check that. I'll put a damp towel in and decrease the pH. I'll aim for 6.2-6.5. I've just bought some pH down, I assume thats the simplest for the job? As for watering schedule, have you a rough volume of water to be feeding? I read you re water when the top inch is dry and water til it starts to run out the bottom. Is this correct? Thanks again!