Ph the cubes to 5.5 and soaked for 8 hrs. Put seeds directly into cubes and covered over. Placed under lights so they get light straight away on the leaves. I planted 5 but only have room for 4 so will pick the strongest ones. My system is 60 litres and I use rain water sterilized for 24hr with h2o2 and hydroguard is always in rez. My starting TDS is 0030.