If you don’t have a growlog please answer these questions.
What strain are you growing? Is it Auto, Fem or Reg?
Are you growing Indoor or outdoor?
Are you using nutrients? Which ones? How much? I am growing white widow gem indoors this showed up today! They were perfect till then. Can anyone tell if
But one photo is not enough to determine. You need to know what kind of nutrient solution you use. Ph of the solution and PPM would like to know what fertilizers you use. But it’s definitely not a fungus. still need a full photo of the plant. At first glance, it looks like a deficiency of calcium, magnesium.
Welcome to the community @Paddy !
I agree that seems to be a Cal deficiency, also is it possible you have been spraying the plant while the light was on? Lights may be to closer too, I can see some spots that have the shape of a water drop.