i picked up all 4 ferts, although i dont really use the k2so4 like a few others. but now i have it in case i need it. Also it only costs a few bucks so it makes sense to just buy it, to find out that you need it one month down the road and to have it shipped separately would be a waste.
aquariumfertilizer.com also is the original that gregg watson created and gave to a couple to keep ferts cheap for aquarists. for that reason they also sell barr's gh booster which is excellent if you need a boost in gh for whatever reason.
if you want the ferts cheaper by volume and locally you could check the sticky at the top of the planted section. the info's in there, i just forget where. anyway you could write down the products and hop on the phone and probably find everything local. having them in one place cheap is convenient for starting out or those of us with only a couple tanks though.
