Top Quality stuff
I use this in my DIY drop checker I made a few years ago and can honestly say this is the best 4DKH I have ever come across. It registers far more quickly than others and very accurate in its reading. You do have to add ph reagent to this, but this is what keeps this solution perfect while sitting on the shelf. You dont want reagent sitting on the shelf for 6 months or a year. You want both separate and only mix the two when your going to use it. Otherwise you need not look any further for a proper 4DKH solution for your drop checker. GLA has the goods.
The most accurate 4dkh on the market
I ordered this to replace my previous 4dkh I got off amazon which was some Nilocg brand. This is far superior, and I have no idea what that other stuff was but it is nowhere near as accurate and quality as this. I tested Nilocg brand and it came out to almost 5DKH! GLA 4DKH, you guessed it, spot on! I feel this is what makes it respond so quickly because after only 30 minutes of co2 being activated its starts to register color right away. The Nilocg stuff seemed to take several hours. This also comes in a large bottle format so it will last me years to come.