Im also growing in soil using general hydro and found even their starter ratio to be too hot for my g13.
I was getting burnt tips an curling when the plant was that size. I guessed that because of the lack of roots, even after a week of straight water there was still plenty of nutrients left in the soil.
Since then i have just been using the nutes when she appears to need something. I am a month into veg and still only feed once every 2 weeks at the general hydro seedling recommended ratio minus some bloom. I am using 1/4tsp micro, 1/4tsp gro, and 1/8 tsp bloom per gallon.