Small white dot

Hi Senhor, to me it looks like a mushroom because it's so white and it looks a bit fluffy in the picture, but the good news is that it's probably just a nothing. The bad news is that i'm seeing some discoloration starting on the serrated edges of the leaf. That's a magnesium deficiency i guess, what happened is you're growing soiless actually. Peat moss is soiless, perlite is soiless , rice husk and calcium carbonat , all of them are soiless so together they are also soiless. That's why you're missing magnesium. So just dont forget to add cal mag and the problem will stop spreading and the plant will recover quickly. Hope this helps ! 🚀