1st time grower Autoflowers

All the plants are doing well. Banana #1 is definitely ahead of the others in her flower but the other two are coming along these are all taken on day 48. They are averaging a growth of 2 cm a day in growth. We have changed them the last two weeks to 18/6 lighting and it seems to be helping them in general. The last two watering they received no food as we felt we had been giving them too much nutrients and wanted to give them a wee break. They will be fed tomorrow. Still not sure what the yellow spots on the leaves are but I think it’s something to do with the nutrients they received, I had thought it was lack of Cal/Mag but no one else thought so. They have never been given Cal/Mag before.