Just Got A 20g Long Betta Tank =d

[Aphotic Phoenix]

Yes the HoB filter will provide the oxygen so an air pump isn't necessary.

The surface agitation caused by HoB filters (and air pumps) increases the surface area of the water which allows for more gas exchange...i.e. more oxygen in the water.

 

[rdd1952]

As a general rule an air pump isn't necessary, especially with a HOB. Surface disturbance is where oxygen is added to the water so if you think you need extra aeration, simply lower the water level a little and let the filter return splash into the water. That should give you all the extra O2 you need.

 

[ayobreezie]

So, yesterday, I went and bought 6 cory's and an ADF... and some plants. Wondering.. if I should use an airpump? The HOB filter seems to be fine, but not sure how much O2 is actually going in... pH is still high.. that's pretty much the only thing I have a test kit for right now.. can't go to the LFS(1 hour away) until Monday.

All the fish seem to be doing pretty well, though.. all the albino cory's swim together.. and the 2 brown ones swim together.. the frog stays in a corner.. different corner everytime I seem him.. and the Betta just swims back and forth all around the tank. I have an artificial decor on the left side under the HOB filter, and the heater is about in the middle, and the live plants are on the right side, away from the HOB filter and fake decor. Does that sound like a good spot to put them? Should I get another filter? Because this filter is rated for 35G tanks.. well, I usually get one step higher... just because it's better to have more than you need.