Egg shell fertilizer. This type of fertilizer works best because it contains calcium carbonate. Air dry some egg shells and then place them in a blender until such time that they become powdery then sprinkle into youre medium. or you can place the shells in water .boil then water and the lit sit for a few weeks. thats the down side thou waiting which iant no good to u
ESPSON SALTS. one tbl spoon to every liter of water and apply to medium...
also dolamite lime. but not to clear how to use it. as ive heard mix reviews. 2 mins go get some info