There are so many test kits that make it possible to distinguish different levels of the same color. It has simple instructions and results.
π Hanna Marine Alkalinity Checker HC - HI772: Accurate & Efficient dKH Measurement
9 Review
Highly Efficient Seachem Purigen for Freshwater & Saltwater Filtration
9 Review
FUNSWTM 7 in 1 Aquarium Test Strips: Accurate Water Testing for pH, Nitrite, Nitrate, Chlorine, GH & KH Levels
8 Review
Fish Water Quality API Test Kit
9 Review
Steam cleaner Deerma Deerma DEM-ZQ610 EU, white/red
68 Review
𧲠Efficient Magnetic Fish Tank Cleaner: KEDSUM Floating Clean Brush with Handle Design
34 Review
Mini pump Xiaomi Mijia Electric Pump 1S, plastic, black
55 Review
Vacuum cleaner TEQQO Aquastick 3 in 1 Power, grey/turquoise
26 Review