Seedling problem, please help!

So I just recently started 3 blueberry fems and 6 god bud seeds from BCBUDDEPOT... They germinated great and started sprouting, I put them into presoaked RW cubes that are 6" and put them under a 400 watt light... I started using dutch master nutes at about 500 PPM with a PH of 5.5-6... The leaves started curling down and the underside of them are looking purple, some of the leaves have brown spots on them.... Any ideas on what this sounds like or what i should do other than flush (which i started doing)... Sorry no pics but i just recently dropped my digi out of a moving car (fuckin wasted!) Let me know what this sounds like... Thanks so much!

Common newbie mistake
flush out all nutes, and do not feed them for the few couple weeks.
right now their over fertizilated and slowly dieing, so do it ASAP

yeah , they dont need nutes till approx 3 weeks.

flush flush flush

I did the same thing with some seedlings. I thought they were dead, but don't give up hope. I flushed and it helped, but they still did not look great. As a last resort (figuring I had done them in) I repotted them in some fresh dirt. The next day they looked sooooo much better and they are growing like crazy. I am a newbie so listen to the flush advise first! Good luck!