Part of your problem is the 50/50 bulb Ema. Only 4.5W of that bulb is producing any light that a plant can use. The other half is a blue light that does not give the plants any of the light that they need. The first thing I would do is get a single bulb that is not a 50/50. Anything in the 5500K to 10000K range would work much better than the 50/50 bulb. I would also put the light on a timer so that you know that it is on the same amount each day. That way if you got symptoms that more time or less time was needed, you could simply adjust the timer in the direction indicated by the plants themselves.

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Fishless cycling