Having problems getting my seedlings going

A customer has a question and I hope we can get some opinions on it, thanks

Having problems getting my seedlings going. I have a 630 watt cmh, and am only running one bulb. At 36” they stretch, and at 24” it’s causing light burn. Moved to 30” and are doing okay ( but apparently stunted)and others are stretching still. Should I just start over? What type of light would you recommend? Trying to start in soil, then transplant to DWC one they have 5 fingered leaves. Just adjusted lights to 530 - 580 umols.

My general setup is 2-2 ft long T5 lights with clones or sprouts in a humidity dome with the humidity dome sitting on top of one of those heating mats. I have a ceramic metal halide but I only put my plants under it when they outgrow their little 1 quart pots. When I transfer them into my final 5 gallon pot then they go under my ceramic metal halide. Wait till some more experienced growers respond but that’s what I do and I have okay success. Good luck and have a nice morning

I should add I am in soil beginning to end.