Problems with seedlings in rockwool

Sup guys! I used to grow soil and sometimes in coco, just had 1.5 years off of growing apart from a few outdoor autos in the summer.
This time I'm wanting to grow captain style (recirculating rockwool system)
The problem at the minute is that I've started some seeds and they're showing weird signs and I can't put my finger on it

I'm using RO water, 6.2pH, 0.3 EC of GH's 3 part base nutrient, also a little recharge to get my microbe colony going early. My seedlings are in rockwool plugs, in a propagator on top of a heat mat, I'm in a 4x4 tent using a SF-4000.
I'm thinking It looks like nute burn, BUT my EC Is only 0.3, if anyone could give advice it'd be much aporeciated

Peace out!

I think it’s too much light or too much nutes, but I can’t really speak on that particular platform of rock wool. Usually in soil I don’t feed anything for a few weeks at least. i think if you were to place the little ones off to the side and not directly under that light and follow the recommended ec/ppm for seedlings in rock wool, that would kill two baby seals with one club and help you get ahead of it.