Attach your choice of ball valve or similar to the OUTPUT side of the denitrator. Remember that you installed 2 fittings during the construction phase. Depending upon your selection of product, you MAY have to use the same method of reducing the tubing diameters as you did when tapping off the pump. I chose the Kent Marine Reverse Osmosis ball valves as they are the correct size and are also small enough to fit in the limited space under a cabinet/stand. By starting with a wide-open flow rate, slowly begin to close the valve until a steady dripping is evident at the output side of the valve. Run your hose back into the sump or into the aquarium and secure it so it doesn’t flop out onto your carpet and ruin your whole day!
Your target drip-rate is fast but not a steady stream! You’ll have to experiment a bit depending upon the model and operation of the valve.
The concept of this project is a hands-free, fiddle-proof addition to your existing system of reef or fish-keeping endeavors. Results are not instantaneous! A 6 to 7 week cycling is required for the anaerobic bacterias to establish themselves AND for the aerobic bacterias to colonize the inside of all those coils winding their way down the inside of the cylinder. Both types of bacteria are required to work in harmony with this unit. Here’s a quick overview of how the whole thing works:

