This is a water only recipe I got from ICMag. I used it last time with the Jabba’s Stash and am confident in it. All the work is done up front. All you have to do is add water until a tiny bit of runoff every other day or so.
Base Mix
7.5 gallons of peat moss
4.5 gallons of perlite
3 gallons of fresh EWC or compost
2.5 cups of dolomite lime
Ammend with
2 cups bone meal
1 cup blood meal
1 cup kelp meal
1 cup greensand (optional)
Mix up the base mix, then take a gallon or two and set it aside to use for seedlings/clones. Then mix in the amendments and let it sit for three weeks or so. Grow your seeds/clones in the base mix in a solo cup for a couple weeks. Transplant to 1-gallon pots of the soil mix. Then transplant again to 3-gallon pots a week or so before flower.
I was able to find everything except the kelp meal and greensand (optional) at Home de Pot. The compost is really important, the higher the quality compost of the better. Coast of Main and Malibu Compost are good brands if you can find them. If you are on a budget, Ecoscraps or mushroom compost will do in a pinch.