Best way to oxygenate the tank?

[cocoa2002]

Hey y’all,

I have a betta in a 5.5 gallon tank, and have been noticed that he’s been frequently swimming up to the top for air and then immediately swimming back down to where he previously was. I assume this is because there isn’t enough oxygen in the tank, so I purchased an air stone. Ever since I’ve gotten it I’ve been leaving it on for 2 ish hours at time (when he likes to hide) because if he swims up, he won’t be able to withstand the current and he’s a curious guy so he’s ALWAYS trying to see where the bubbles are coming from. Are there any other ways I can oxygenate the tank? I want to make sure there’s plenty oxygen in the water at all times rather than just leaving the air stone on for hours at a time, I also just don’t want to cause him a lot of stress from not being able to swim.

Thank you!

 

[LMO]

Bettas have a labyrinth organ so have to take air from the surface even if the water is well oxygenated. Does the tank have a filter as this will provide surface agitation and keep the water oxygenated?

 

[DuaneV]

That's totally natural. Like LMO said, theyre a Labyrinth fish so taking air above water is totally normal.

To answer your question, the only way to add oxygen to the water is through surface agitation to aid in gas exchange. I run sponge filters only in all my Betta tanks, so that's the only surface agitation my Betta tanks see, but I will say this: I don't run airstones in ANY of my tanks. Never have. As long as you're using a good filter that's turning over the water and your tank isn't insanely overstocked (which would cause other problems), your tanks probably getting adequate gas exchange.

 

[cocoa2002]

Bettas have a labyrinth organ so have to take air from the surface even if the water is well oxygenated. Does the tank have a filter as this will provide surface agitation and keep the water oxygenated?

Yep! So assuming there isn’t any way for them to develop hypoxia (with just the filter running)? I just get nervous when I see him come up but if that’s just what they do I guess I won’t stress over it.

That's totally natural. Like LMO said, theyre a Labyrinth fish so taking air above water is totally normal.

To answer your question, the only way to add oxygen to the water is through surface agitation to aid in gas exchange. I run sponge filters only in all my Betta tanks, so that's the only surface agitation my Betta tanks see, but I will say this: I don't run airstones in ANY of my tanks. Never have. As long as you're using a good filter that's turning over the water and your tank isn't insanely overstocked (which would cause other problems), your tanks probably getting adequate gas exchange.

Yeah, there’s definitely surface agitation and there’s only one fish in there so I guess he is getting enough oxygen. I have a mechanical filter though, and this might sound kinda dumb but what’s the difference between a mechanical filter and a sponge filter?

 

[DuaneV]

Theyre the same.

There are 3 types of filtration for our tanks: Mechanical, biological and chemical.

Lots of mechanical filtration also houses biological filtration (the beneficial bacteria that converts ammonia and nitrites to nitrates). A sponge filter draws water through it via back pressure from an air line. It will suck up small waste particles that are close enough to get drawn in, just like a HOB or canister. Inside a HOB or canister are filter pads, bio rings, sponges, etc., where the beneficial bacteria live. My sponge is out in the open water doing the same job as a sponge sitting in a HOB. I only use sponge filters in tanks under 30 gallons. I use HOBS from there up, and canisters/HOBS/sponges in any combination on larger tanks (over 55 gallons). You can run a huge sponge filter on big tanks and that's it. Most pet shops used to be set up like that.

 

[Gone]

And frequent partial water changes.

 

[ystrout]

As others have said, that's normal. Fish like bettas and gouramis actually breath air in conjunction to breathing through their gills. People actually put little fake leaves on a suction cup called betta hammocks an inch or two below the surface so the fish can sleep right next to the surface and easily breath without having to move too much.

If you have a filter, your tank will be oxygenated enough. Whether it's a HOB or sponge filter, both will agitate the surface plenty. You won't need a bubble bar.

 

[Momgoose56]

Yeah, there’s definitely surface agitation and there’s only one fish in there so I guess he is getting enough oxygen. I have a mechanical filter though, and this might sound kinda dumb but what’s the difference between a mechanical filter and a sponge filter?

Mechanical filtration is the part of a filter that removes solid particulate matter from the water. HOB's and Canister filters do a good job of mechanical filtration because they move large volumes of water through various densities of foam and mesh filters. Sponge filters do a less efficient job because water movement through the sponge is typically passive and low flow.
Biological filtration is the flow of water through porous media that holds the bulk of the beneficial bacteria in a tank and exposes ammonia and nitrites in the water to those bacteria for oxidation. Mechanical media (sponges and mesh) serve a dual role -in biological and mechanical filtration. Chemical filtration is filter media or mechanisms that remove dissolved particulates (medications, ammonia, chemicals, some metals and toxins) from the aquarium with activated carbons, resins, and other adsorbents.

 

[JayH]

To answer your question, the only way to add oxygen to the water is through surface agitation to aid in gas exchange.

This is not actually true. Oxygen exchange at the surface is the primary way of getting oxygen into the water of most aquariums, but it is definitely not the only way. Air stones or air driven sponge filters will increase the oxygen level in the tank. Some of this is due to additional surface agitation, but some is also due to gas exchange into the water from the bubbles.

Taken to the extreme, injecting micro-bubbles of pure oxygen into the water will increase the level of oxygen in the water by a very significant amount if done properly. No normal person is going to do this on a home aquarium, but it demonstrates that there is gas exchange between water and bubbles, so it only stands to reason there will be similar exchange with air bubbles introduced via a normal air stone.

The same principle of gas exchange from bubbles is used when injecting CO2 into the tank for plant growth. What works for CO2 will also work for oxygen.

It should be mentioned that research indicates a higher oxygen level is good for the fish. In the oxygen micro-bubble experiments juvenile fish put on significantly more weight than the control group. They also tend to be more active.