DWC-Bucket-System-Grow my equipment and questions

[polishpollack]

If you can show pictures taken in white light, that would be good. Yellow tips early on could mean either too much fert or not enough. Hard to tell right now. Need to know how you're ferting them, how much, what you're using, how often, also include pics of entire setup, or description.

[Growlie]

First time I used fert was idk - maybe at day 4 or 5. I use General Hydroponic ferts and added like 4 drops of bloom, 4 micro, 4 grow in 400ml and I was at about 420 ppm haha. Never watered after that because the rockwool wasn't dry. I've attached a picture of a leaf tip (the other one looks the same) and my set (description in the first post).

[Growlie]

Forgot to tell you the ppm of my normal water. As mentioned I had 420 ppm and 200 ppm is my tap water so 220 ppm came from the fertilizer.

[polishpollack]

How are things looking so far?

[Growlie]

Everything's fine yet. Since flushing the yellow spots aren't expanding anymore and the new leafs don't have yellow spots. I also bought a humidifier because the humidity is extreme low (~30%) but it didn't arrive yet. I hope they deliver it today. Plant is still growing but not extremely rapid (idk how fast they usually grow from seed) and the leafs are looking really droopy what could be the problem? Humidity? I've attached a picture of the plant which I took some minutes ago. 12 days 18 hours ago the plant appeared on the surface maybe you can tell me based on the pictures and based on it's age if it's growing alright or not.