if you want an accurate soil tester expect to pay out the nose for it. $500 ballpark!! thats just for the ph
Your best bet would be a high quality pen that does both ec and ph, try hanna, eutech, control wizard, etc.. check the water befor and after (the FIRST FEW DROPS/ OR ABOUT A LIQ OUNCE) coming out the bottom of the pots, then you know what is happening in the soil. get a light meter from a photo supply shop, or just shoot for 50-75 watts per square foot; more than that and you will need some co2 enrichment.