yes, you do want to be checking your water ph.. it should be between 6.5 and 6.8.. get a good digital ph meter... they can be pricey, but are well worth it...around $75 or so for a good one.. and get ph up and down to adjust with.. you also want to ph your nute solution, but wait till after you put the nutes in to check it.. let me tell you why.. my tap water is around 8.6, and after i add my fox farms nutes, it drops it down to right around 6.6, and i don't need any farther ph adjustment.. so if you were to adjust it before adding your nutes, you may just end up adjusting it twice.. and it really is silly to waste your time like that, lol..
now i hate to admit this, but you should also check the ph of your soil, but i am not exactly sure of where it should be, so i don't want to give you some bum advice...
those number you mentioned are the npk ratios of the nutes.. nitrogen, phosphurus and postasium... that much i know.. i am not sure how you know what they should be.. i know my fox farms stuff is around 10/8/7 or something like that.. but like i said.. its just a ratio of what is in it, so 30/20/30 should be the same as 3/2/3 if that makes anykind of sense to you.
hope this helps you out some.