Air pump/sponge questions

[elisa001]

Hi everyone I have a sponge filter rated for 15 gallons attached to about 6 feet of airline tubing to an air pump rated for 20 gallons under it. This is not the main force of filtration in my 55 gallon tank. I just have a few questions...

I also have another sponge filter in a smaller tank and it is very effective and I can see particles being sucked into it. This sponge filter is not like that. It has been installed for a few weeks and I have never cleaned it and there is nothing on it which leads me to believe it’s not actually filtering the water, just adding aeration.

Like a water pump, do air pumps loose power when they have to pump air vertically? The smaller air pump only has about 18inches of tubing and it right next to the tank, as opposed to the larger one which is far under the tank.

Also is the air stone placement inside the sponge filter important? I manually added and air stone into the top part of the larger sponge as opposed to the bottom part of the smaller sponge.

 

[FinalFins]

Hi there,

Sponge filters don't show much power naturally but if you want it to be more powerful, send as much air possible to the filter.

I don't have any proof but common sense tells me that since gases are very lightwieght it won't be too hard for a air pump to pump vertically.

I have 2 sponge filters and I see no difference in placement of air stone.

 

[Mongo75]

You need the air stone as close to the bottom of the sponge as you can get it.

 

[Sanderguy777]

You need the air stone as close to the bottom of the sponge as you can get it.

Yes. The longer the uplift tube is, the more force is transferred from the air to the water in the tube. I haven't seen any (or done my own) experimenting with how much flow you can realistically expect from different ID (inner diameter), length, air volume, and air bubble size, but longer is better and smaller bubbles are better (just confuse those wooden stones as they kill pumps with too much pressure.

Vertical lines shouldn't affect the pump nor should length of the air line. The depth of the water in the tank, and the size of the pores in the air stone are the real contributing factors for weak pumping (assuming your pump is sufficient for the tank size/depth).

Add a longer uplift tube first, then try changing the stone out to a Neverclog, upgrading your air pump, or getting an additional one to run along with your original one.