Checking the pH with Hydropnics

When you are growing hydroponically checking and adjusting pH is a simple but very important thing to do. There are several ways to check the pH of the nutrient solution in your hydroponic system.

HTGSupply.com sells all of these products, look on their webpage under Monitering and Test Equipment.  To start, you can use paper test strips which are the most inexpensive way to check the pH of the nutrient solution. These paper strips have pH sensitive dye which changes color when dipped into the hydropinics nutrient solution. You then have to match the color of the strip to a chart to see what the pH is. These test strips are inexpensive, but they can be hard to read, because the colors differences are subtle. If you are going to be trying different nutrients etc. or are seriously into growing hydroponically, you might want to get a digital pH meter.

A step up from the paper test strips are liquid pH test kits. These are more a popular method to check pH for the hobby gardener. These liquid test kits work by adding a few drops of a pH sensitive dye to a small amount of the nutrient solution and then comparing the color of the resulting liquid with a color chart. While slightly more expensive than the paper test strips, they are easier to read and are more accurate and reliable.

The Most high-tech way to check pH is to use the digital meters. These meters come in a huge array of sizes and prices. Unless you are also going to use your pH meter for chemistry, YOU DO NOT REALLY NEED A METER THAT GOES FROM 1-14, you only need a meter that checks pH between 4-9 since that is the range plants need. With most  digital pH meters you simply dip the electrode into the nutrient solution for a few moments and the pH value is displayed on an LCD screen.
The problem with hydroponics is that while it gives the grower more control of nutrients and pH it is also easier to mess up. The same goes for a digital pH meter.  Digital pH meters are very accurate (when properly calibrated) and fast but they need to be cared for properly however, or they will quit working. The glass bulb electrode must be kept clean and some are required to be wet at all times. What these pH meters are doing is checking the voltage in the water, so corrosion or misuse of equipment will break the device. The pH meters usually need to be calibrated frequently, (Just follow manufactuers instructions) as the meters can drift (give the wrong pH value) and to insure accuracy you must check calibration often. With some digital meters, the tip needs to be stored in an electrode storage solution or in a buffer solution and should never be allowed to dry out
The pH meters are slightly temperature sensitive. Many of the more expensive pH meters on the market have Automatic Temperature Compensation (ATC), which corrects the reading with respect to temperature. On meters without ATC the pH should be checked at the same time of day each time in order to minimize any temperature related fluctuations. Again, you don’t need ATC if you will always check at the same temperature, don’t buy all the bells and whistles if you don’t need them.
Due to the fact that pH meters have a reputation of breaking down without warning it is a good idea to keep an emergency backup for checking pH (paper test strips or a liquid pH test kit), just in case.
Good Growing,
Dr. E.R. Myers

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