The Aquarium Tank – Measuring Flow
Here is how I measured the flow from my gravity-filter air pump.
I took a clean cooking tray and floated it under the outlet, the bubbler that drags water up with it. I started my timer running.
After three minutes the tray was almost full, so I took it and poured the water into a measuring jug. 1.5 litres each three minutes, or 30 litres per hour.
Given that my tank’s capacity is about 70 litres, it will take over two hours to pass the water through the gravel filter. In practice, some of the water will pass through multiple times, and some not at all. There is a distribution curve.
Nonetheless I have a base figure for water circulation, and that is better than no figure at all.
The Aquarium Tank – Improving Flow
I removed the air tube from the Pump Tube and grabbed a Wooden Chopstick from my cutlery drawer.
I plugged the tube with the tip of the chopstick, and used a safety-pin to set a dozen or so Fine Holes in the tube immediately behind the wooden plug.
I am rewarded with Finer Bubbles, which means more Surface Area of bubbles, which means more water being Pumped through my Gravel Filter.