If you want accurate pH, you are going to have to shell out like $300+ for a good pH meter and probe, we are talking lab grade here. The RK2 by the reviews I have read seems to keep things in check and provides an accurate reading. Its not so much the display/control device as it is the probe. A cheap probe will get you in trouble and start throwing reading all over the place. Probe maintenance is very important and you should be cleaning it weekly and recalibrating often (weekly or more). You can buy pH buffer pretty cheap from lab suppliers. I have seen Online Salt and Reef stores really jack the price of this stuff up 3x of what it costs. Also, you can't beat the RK2 other features including temp. You will read story after story of failed heaters. With a controller, if he heater fails, the controller will cut the power to it.