Review on 🌱 Bluelab METCOM Combo Meter: pH, Temperature, Conductivity (Nutrient) Monitoring for Hydroponics and Indoor Plant Grow - Easy Calibration and Digital TDS Tester. Pack of 1. by Aaron Schultz

BlueLab METCOM is a near-perfect instrument (at least in the short term). He does what is expected of him, within his limits. BlueLab doesn't claim that this is more or less than what it offers. The PH seems to be very accurate. I calibrate frequently and it never seems to be necessary, although the probes are in the nutrient reservoir 24/7 (I put the probe in a Kcl solution about a day a week to keep it healthy). The TDS meter is fine for its intended purpose - nutrient solution maintenance, but it is not accurate enough to measure raw water/reverse osmosis/deionized water quality. You'll need a cheap stylus for this, I use a Membrane Solutions TDS stylus, it seems Pretty much on a teenage TDS level (less than $20 and comes with a nice magnetic case). The thermometer is slow to respond (built into the TDS probe and has a lot of mass) which is good as a very rough idea, but I have a reading of about 3 degrees Fahrenheit and it only shows full degrees (no tenths). Here I chose the VEE GEE Scientific 83110, an excellent thermometer (see my review). The BlueLab thermometer is accurate and repeatable enough to determine if you have a radiator problem or something similar. I don't like that I don't have a comparison/backup for everything, so I just ordered the '2 in 1 pH Temperature Monitor' (Revain of course) for about forty bucks (20 less than the BlueLab probe). Review in a month or so. (it's 7/21) With this device you can check your hydraulic system anytime by pressing the button to read, 3 clicks and I have PH, TDS and Temp and I know everything is ok or if I can solve the problem got to . No rinsing, opening reservoirs, calibration checks or similar in the pen and no risk of dropping the pen. This whole PH pen thing is just PIA and doesn't encourage frequent checking. Styluses are generally less accurate unless you're spending almost as much as you'd like on this handy device, and styluses are often impossible to replace. Due to their construction, pH sensors have a limited service life. Keep a litmus test or pipette kit handy, JIC.BlueLab products are inexpensive, very reliable, and fairly accurate (but very reproducible). This meets the needs of many users. If you fit, this is a great solution and I will be using BlueLab tools in the future.