It’s very important for hydroponic gardeners to keep a regular check on the pH levels of our hydroponic solutions. For this, we need access to a high quality hydroponic pH tester.
The pH scale ranges from 1 to 14 and it’s used to measure acid to alkaline balance. The pH reading of 1 is the most acidic while a pH reading of 14 is the most alkaline. A pH of 7 is neutral.
If when testing using the pH scale, a full point change in pH means there is a 10 fold increase or decrease either in acidity or alkalinity. Water with a pH of five is 10 times more acidic than soil or water that has a pH of 6. Water which has a pH of 5 is 100 times more acidic than water that has a pH of 7.
If you would like to keep a strong and healthy hydroponic garden then it’s essential you keep check of pH levels and control them where necessary.
If the pH in your water is too low, for example it’s too acidic then your plant roots will be unable to absorb many essential nutrients. If the pH in your water is too high then this will cause nutrients to simply be unavailable.
The vast majority of plants you could ever grow, especially in a hydroponic garden will do really well within a pH range of 5.5 to 6.5. Having said that you can quite easily get away with fluctuating a half point in either direction without causing too many problems, but larger deviations will effect element solubility.
When the plant roots take in the different nutrients, of which there are many, at different rates then this causes nutrient solution to change pH levels. This is why you need to do regular testing on your nutrient solution with a high quality hydroponic pH tester, preferably an electronic hydroponic pH tester to ensure it’s between the levels of 5.5 and 6.5.
Testing pH Level In Hydroponic Solution
There are two main types of pH testers; reagent hydroponic pH tester kits and also electronic hydroponic pH testers.
Reagent Hydroponic pH Tester Kits
I’m sure you remember using these pH meters at school whereby you would take the solution you needed tested and would add a few drops of the pH test reagent solution. You would then put a few drops on some litmus paper and observe the change in color and compare it to your pH chart to get the pH number of the solution.
This mature method still works great, even for the most ardent and tech savvy hydroponic gardener. However, with constant testing, you will run out of litmus strips and/or indicator solution and you’ll have to buy replacements.
Which is why I prefer the latter method.
Electronic Hydroponic pH Testers
Electronic pH testers are economical and convenient. They work by measuring the electrical current between two probes. I much prefer the electronic method as they are extremely accurate, much quicker and far less hassle. You will also be able to use your electronic hydroponic pH tester thousands of times whereas you won’t be able to do this with the former method.
I’ll also point out that you can get “perpetual” pH testers where you leave a prod attached to a reader in your solution permanently. The reading will change as the solution does.
Once you know what the pH of your solution is then you’ll know whether to leave your solution as it is for a few days, or whether you need to add any hydroponic nutrient solution to re-balance your pH levels.