i tryed to give only water at first time but was the same, they just stop growing at that point when first true leaves apears, i ruin hundred seeds and still cant get ower seedling stage, only few roots comes out of tha biger rockwool cube ant stops growin
maybe its like you said for owerwater. maybe its to much water holds in that cube its the only thing that i havent tryed yet,maby rockwool cube need to dry out a little