The aquarium filter powered by an air pump shown in previous videos can be modified to serve as a sponge filter.
Let's assemble the telescopic tube.
Use a rubber band to make a stopper on the thin (top) end.
I use padding polyester instead of a sponge.
Wrap a strip of filtering fabric around the tube.
Secure the roll with a rubber band.
Insert the air tube into the thick end of the telescopic tube.
Move the roll to cover the hole.
We have made the sponge filter.
Let's test it in a plastic bottle aquarium.
I put the telescopic tube through a funnel in a planter.
The air tube goes through another funnel.
The filter goes inside of the aquarium.
Adjust the air tube closer to the bottom of the telescopic tube.
I made a cover out of a small plastic bottle to prevent water spills.
Attach the air tube to an air pump through an airline control valve.
Turn the air pump on.
Water flows through the sponge (filter) up the telescopic tube and then drops back in the aquarium.
It creates slow water flow in the aquarium.
We can use this sponge filtering system in any aquarium.
This is an example of an installation in 10 gallons aquarium.
There is a different way to set up a sponge filter.
Insert the air tube from the top.
And push it closer to the bottom.
It looks neater, but works better in aquariums with higher water levels.
I use a wire plant holder, in this example, to hold the installation.
Have fun and happy aquarium :)