Before you test, make sure your tank is mixed thoroughly. pH can shift after changes, so if you have topped up with water or added supplements, stir the reservoir well and then let the solution stand for 30–60 minutes. This short settling time helps the reading reflect what the plants are actually getting.
Take the included test tube and collect a sample of your nutrient solution. Fill to a consistent level each time so your colour results are easier to compare from test to test. Add one drop of the concentrated indicator solution to the test tube, then gently swirl to blend. The solution will change colour.
Hold the test tube beside the colour chart and match the sample colour to the closest colour block. That match is your pH reading. For the clearest comparison, use bright, even lighting and avoid tinted grow-room lighting when possible.
For best results, check pH daily and always test again after any reservoir changes. Hy-Gen notes that nutrient solution is typically kept slightly acidic for most plants, commonly between pH 5.8 and 6.5. If your reading drifts outside your target range, correct your reservoir and re-check to confirm you’re back where you want to be.
To keep your pH testing consistent over time, rinse the test tube after each use so residue doesn’t affect the next reading. Store the kit where it’s easy to grab, because quick routine checks are the easiest way to catch pH drift early and keep your hydroponic system running smoothly.