Maintaining proper CO2 levels is an important factor in the health of your planted tank. A CO2 drop checker is an essential tool for monitoring CO2 levels. The drop checker is a reservoir designed to contain an indicator solution and an airspace.

You Need:
4dkh solution
reagent solution
drop checker

I do not sell 4dkh solution as you can make it yourself for the price of baking soda.
It is important to be accurate

0.12 grams of Baking Soda
1 Litre of distilled or RO water
Mix the two together and you have 4dkh solution which will last for years. Better than paying a fiver for 100ml.

INSTRUCTIONS FOR DROP CHECKER
Use a pipette or other way to fill the bulb section about half full of 4dkh solution.
Add 3 drops of reagent solution and give a quick shake. the colour should be blue.
Place inside the tank away from the diffusor and wait about 2-3 hours and check colour against the reagent chart to tell you how much co2 is in your tank 24/7.

Yellow is too much
Green is normal
Blue is not enough.

*PLEASE NOTE*
The reading you see is approximately 2-3 hours behind
You only need to change the drop checker water when its colour stops being vivid or you want to clean it.
95% of all algae problems are related to insufficient co2 so it is very important you know how much is going in