There are a lot of different ideas on how to start seeds in hydro. I use what you have and haven’t had any issues with them yet.
Seedling stage last about 2-3 weeks after breaking ground. Technically the seedling will live with no nutes for that period of time. The cotyledon leaves will feed the plant during that time. I don’t put them in my net pot till they have about 3-4 sets of leaves.
I then set the water 2” below the netpot. The air stones will bubble water up onto the roots enough to get them going, provided you have strong enough air.
If that’s the only tote your gonna grow in, you might want to consider growing just two plants in there. It is recommended each plant be about 2 ft apart. They will get BIG!
You can do clones like you have them but full plants will get real crowded quick!
After seedling 2 or 3 weeks, I would start nutes out around 200-400 ppm’s. Increasing each week or as needed.
I use Jacks nutes which to me, takes all the guess work out of feeding plants. You just mix and feed.
Now, if your environmental conditions are pretty stable, nutes will stay the same and PH will stay the same as the water level drops.
I would recommend draining some water out and filling back up till your ppm’s res reaches about 350-450ish ppm’s. PH at 5.8. They’re not gonna use much nutes at all for another week or two.
Do you have an overall picture of your setup?
Do you have a way to control your water temp?
Babies are looking good!