Review on Accurate Hydroponic Growing: General Hydroponics 4 01 Calibration Solution by Omar Alradwan

A great calibration solution so far. Arrived on time, colors help a lot and seem very accurate as advertised. The best advice I can give to others is that you NEVER want to EVER dip your equipment directly into these calibration bottles as you will instantly contaminate the solutions and waste your money (no matter how hard you try to avoid). ). Instead, ALWAYS pour a small amount of each solution into separate containers (shot glasses work well, heh) and submerge the devices in these separate containers to avoid contamination or the original sources of the solution. General hydroponics if you listen to this the only design change I would like to see on this product is maybe add a small dent to the rim of the bottle cap. The surface tension of the bottle material creates a solution flow that does not pour well, and a small dent makes the pouring or pouring effect much easier, and the product user experience is much more comfortable.