Hello dlove,
I use Earth juice granular (dry) pH adjusters. It's not that expensive, and a little goes a long way. One, 1 pound container of each (up and down) has lasted me over a year now (although I should get more). It usually runs between $7-$10 for one pound, though I am seeing that most places are selling it in 2 pound containers. Here is a link to a place I found that sells it in one pound containers. But a lot of other online hydroponic supply stores carry it.
Earth Juice Natural pH up & pH down - Plant It Earth
Earth juice does make liquid pH adjusters, but then you pay to ship all that water it's mixed in. The dry (granular, also sometimes called crystals) is a better deal as far as I'm concerned.