Yep.How are your plants doing?
An all in one complete fert like TNC Complete , seems to be the current favourite.All in one contain trace as well as N&P (which you'll need if using carbon)
Otherwise you can buy the component dry salts from here. Cheaper in the long run.
Use this calculator to help work out what to buy & how much to use.
edit:i currently use carbon & TNC comp.the fert is 1ml per 20L daily.I do 50% wc every week