HELP! First timer and failing left and right.

I can't seem to get past seedling stage even! Christ!
I planted these seedlings in Rockwool 3 weeks ago:
. I already killed 2 seedlings and 2 remaining is getting $$$

I just planted the little guy into the DWC because he did NOTHING in 2 weeks....
The other one in the pic is a new seed I started Friday and one more in the back
I have tried it all PHed my water,added a bit of nuts after 2.5 weeks of nothing...
I am exasperated. I put in DYNA Gro "GROW" "PRO-TEKT" and "K-L-N" I get 337 on the PPM meter and it reads 130 on just my tap. I have a PH at about 6.
So, how am I doing?

The way I do it is once the seeds sprout in the rockwool, give tap water once every 24-36 hours; there is no need to ph plain tap water. After one to two weeks when the second set of leafs are about the same size as the first (not the cotyledons), you can prob begin feeding DG grow at about 100ppm, or 200-230 total ppm (x0.5) with tap. If you notice the green color fading to yellow before then, go ahead and give mild dose of nutes. Keep it around 100ppm and you should have no worries of burn IMO.

Leave them in a seedling tray or whatever for 2-3 weeks depending on size. Once you get a few roots popping out of the rockwool, then transplant to dwc buckets.

Hold off on pro-tekt and kln until you get a good root system and are into veg.

Are u pre soaking the rockwool in 5.5 ph water?