The CAL Aqua Labs Double Counter THERE operates exactly the same as the original Double Counter, but has an external opening to him, easy to fill.
After the passage of time, the water in the bubble counter evaporate by the constant passing stream of dry CO2. He will therefore need to be replenished to the original level. Normal bellentellers should be disconnected from the CO2 hose to fill up. This is uncomfortable and can eventually the hose to stretch, so CO2 can escape.
The CAl Aqua Labs Double Counter can be quickly and easily refilled through the silicone plug to take out and water fill hoses to remove. Place the plug back again and you're done. It's that simple!
The CO2 bubble counter is supplied with 2 clear transparent suction cups. This allows on the side of the aquarium to be confirmed. Exclusive Check Valve. Size approx. 95x17mm (Hxw)
Always use a Check Valve to prevent water in the CO2 system.
Read here: all about adding CO2 in the aquarium