Click or scroll to zoom Tap or pinch to zoom AA pH Test Indicator by Active Aqua Sale $5.99 SKU 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Buy Now The Hydroponic pH test kit is good for 150 tests. At the rate of 3 tests per week it will last one year, making it excellent value for money. This kit covers a pH range of 3-10 measuring in 0.1 increments.