This is an easy to make, cheap filter with many advantages.
Make sure you pre-rinse everything with used tank water or treated water. Since carbon should be rinsed for about 5 minutes, you can use tap water then rinse thoroughly with mentioned treated water.
You can really use any filter medium in this filter and add as many layers as you want, just make sure that water flows easily.
Just keep the sponge sticking out of the bottom to promote flow and prevent fish “suck up” and keep the filter floss at the top for fish safety and to hold everything in.
When you fit the sponge, don't squeeze it into the tube. Water flow is more important than having the sponge cover every area of the tube.
When making the filter fiber section, you can make 2 distinct layers so you only have to "switch out" one of them as maintenance, keeping some bacteria intact.
The diameter of the tube and air flow rate depends on the size of your tank and tank load of fish.
Some similar designs for bigger tanks use 2 or 3 liter bottles for a tube.
Make sure that the air delivery device is AT LEAST half the diameter of the tube.
If an air stone is not big enough, you have to make one (a line in the top of a cut-off bottle top with holes punched around the perimeter works well).
You can always make 2 filters for more volume as well as a back up.
The advantages of this filter:
EZ to make and maintain.
Dual bio-medium (sponge and filter fiber).
It can't "suck up" your fish.
It aerates as well as filters.
Affordable: You can even make 2 filters for a back up and you can have back up air pumps.
You can make one for a back up even if you have an expensive filter set up.
The disadvantages of this filter:
It can have lower flow rate, depending on the air pump.
If you need more flow rate, it can cause a lot of disturbance from the air.
If you use a clear tube, you must think about the color scheme or it can be unsightly (black for every medium looks decent).
Even though this is a low profile design, it still takes up some room inside your tank.
Maintenance:
Check the water flow once a week by pulling the top of the tube out of the water a bit and see if water is flowing.
Alternatively, while doing a partial water change, you can watch when the water level hits the top of the tube to see water flow.
Clean the sponge every 3-6 months by squeezing it out, you can also rinse it with used tank water.
Change the filter fiber every 3-6 months (make sure you leave a little of the old in with the new to keep the bacteria).
If you ever replace the sponge, make sure you don’t change any of the filter fiber for a couple months.
If you use carbon, change it every month (you wont need it for very long unless you need to clean medication or bad smells, remove it after a few months).
Change the gravel every 1-2 years.
Otherwise, change the filter fiber and rinse the sponge as needed.
If you find that you need to maintain the sponge more often, then change everything else more often as well.
Make sure you pre-rinse everything with used tank water or treated water. Since carbon should be rinsed for about 5 minutes, you can use tap water then rinse thoroughly with mentioned treated water.
You can really use any filter medium in this filter and add as many layers as you want, just make sure that water flows easily.
Just keep the sponge sticking out of the bottom to promote flow and prevent fish “suck up” and keep the filter floss at the top for fish safety and to hold everything in.
When you fit the sponge, don't squeeze it into the tube. Water flow is more important than having the sponge cover every area of the tube.
When making the filter fiber section, you can make 2 distinct layers so you only have to "switch out" one of them as maintenance, keeping some bacteria intact.
The diameter of the tube and air flow rate depends on the size of your tank and tank load of fish.
Some similar designs for bigger tanks use 2 or 3 liter bottles for a tube.
Make sure that the air delivery device is AT LEAST half the diameter of the tube.
If an air stone is not big enough, you have to make one (a line in the top of a cut-off bottle top with holes punched around the perimeter works well).
You can always make 2 filters for more volume as well as a back up.
The advantages of this filter:
EZ to make and maintain.
Dual bio-medium (sponge and filter fiber).
It can't "suck up" your fish.
It aerates as well as filters.
Affordable: You can even make 2 filters for a back up and you can have back up air pumps.
You can make one for a back up even if you have an expensive filter set up.
The disadvantages of this filter:
It can have lower flow rate, depending on the air pump.
If you need more flow rate, it can cause a lot of disturbance from the air.
If you use a clear tube, you must think about the color scheme or it can be unsightly (black for every medium looks decent).
Even though this is a low profile design, it still takes up some room inside your tank.
Maintenance:
Check the water flow once a week by pulling the top of the tube out of the water a bit and see if water is flowing.
Alternatively, while doing a partial water change, you can watch when the water level hits the top of the tube to see water flow.
Clean the sponge every 3-6 months by squeezing it out, you can also rinse it with used tank water.
Change the filter fiber every 3-6 months (make sure you leave a little of the old in with the new to keep the bacteria).
If you ever replace the sponge, make sure you don’t change any of the filter fiber for a couple months.
If you use carbon, change it every month (you wont need it for very long unless you need to clean medication or bad smells, remove it after a few months).
Change the gravel every 1-2 years.
Otherwise, change the filter fiber and rinse the sponge as needed.
If you find that you need to maintain the sponge more often, then change everything else more often as well.
... keep shaving material if you need to force air...