How much water for 4 week old plants in 3 gallon pot - 24” from light?

You must pour enough water until you see some water coming out from the bottom of pot. Then you just need to lift your pot and to keep the weight in mind. When the pot isn’t that heavy anymore, it means it’s time to water again. By doing so, you will follow your plants needs without giving too much or not enough.

Ciao fratello. Devi versare acqua fino a quando non vedi uscire acqua da fondo del vaso. Per prima bagna un po' il substrato. Tipo 300 ml e aspetta 15 minuti, per essere sicuro che parte della terra all'interno del vaso sia umida e possa assorbire l'acqua. Se vedi uscire acqua dai fianchi del vaso non è runoff. Io per bagnare verso lentamente un po' d'acqua, aspetto 15 minuti, verso un po' più acqua e spetto 5/10 minuti, e così via fino a ottenere acqua che esce dal fondo. 5/6 giorni e il vaso sarà molto più leggero, segno che dovrai bagnare. Buona fortuna 🤞✌️

What do you mean by runoff?

Water in a circle around the outside of the leaves until you get the runoff. Check ph is in range.

Also my overwatered girl had leaf tips like your girls lower leaves at first as well. I'd also recommend some beneficial bacteria to help with your roots. I use 3.. a little overkill but if I had to pick one it would be great white. They will pick up dont worry!

Hey mate, I'm in 3 gals as well. I water 2L when the pot is light it gives me 20% runoff. Normally takes about 4 or 5 days for my girls. They are a little bigger so you may be longer. That's all depending on temps and RH though. Best think you can do is water when light. I stunted one of my plants for 4 weeks (plant at the back of my photos) started new seeds and watered her in this way and she has picked up massively and my 2 new girls are growing nicely. If your a little uncomfortable with the weight have a feel of the top few inches of solid when you think it's time just to double check at first. They need a little time to dry out a little to make a large, healthy root system Hope this helps 🙂👍