Review on Fluval A7551 CO2 Indicator Kit by Alexandra Baker

The design makes it very easy to read and looks pretty cool and modern. Basically, this product works like this.1. Remove the cap and pour in 1ml of the provided solution (fill to the line, easy).2. Put the cap back on the base (with suction cup) and slowly turn it over so the tip is facing up.3. Place in the aquarium, preferably in a place where no air bubbles can be trapped underneath that could spoil the result.4. Give it a few hours first to get the right readings. A few placement tips: - If air bubbles are trapped underneath by the CO2 vent (etc.) or just a regular vent, this will lead to inaccurate results. - Try to place it 4-5 inches from the top of the tank in a spot where you can see the color clearly. Make sure your tank has good water movement to ensure accurate results. I think I will change the solution every 3 weeks? It also only contains 10ml of solution so it doesn't last that long. About 6-8 months later. This is a great little tool to help you determine if your plants are getting enough CO2. It won't tell you ph or kh and they have to be tracked separately. All in all, this works great and is the best in the business if you don't mind swapping out the solution every few months.