stefuanswered grow question 4y ago The plants are actually quite dark green, looks like a slight over-fertilization. It's hard to judge under artificial light, but they often look brighter under artificial light than they actually are. And the spots on the leaves look like a calcium deficiency. I wouldn't give the plants any more fertilizer and just a bit of calcium. Calcium is usually added through tap water, which is often referenced in fertilizers. You should check what the EC value of your tap water is; if the EC value is quite low, under 0.3, you should definitely add a bit of calcium and also magnesium. Magnesium is often sufficiently present in the soil.
If I were you, I would first find out how high the EC value of your water is. If it's lower than 0.2, then it's clear that a calcium deficiency is unavoidable over time.