Aeration and Surface Agitation Question

[sobersteve323]

Would a strong current at the surface cause aeration or does the surface of the water actually have to break?

I'm asking because I have my Fluval 405 outlet under the surface so that it creates a strong current, but no actual breaking of the surface (so that it's quiet). I have 3 air stones setup throughout the tank for aesthetics, but I might end up removing 1 or 2 if I rearrange and I don't want to do it if it lowers the oxygen level (if this is the main source of aeration).

The tank is empty while cycling, but I don't want to suffocate the fish once I do start stocking!

 

[BBradbury]

Aeration Question

Hello sober...

The oxygen in your tank is based on the stirring activity on the surface. The airstones produce more oxygen than the current equipment. If you take away a couple of airstones, you'll reduce the oxygen in the tank.

Once the tank is cycled and you add a few small fish, one airstone will be plenty. It would be a good thing to add some fast growing stem plants to the tank too. Once the plants are established, you'll have another oxygen source.

Just an FYI, you won't be able to have multiple airstones and a lot of plants too. Oxygen is a plant waste product and your plants won't survive very long in a high oxygen environment the airstones will create.

B

 

[Bubble_B0y]

Unless you have a spray bar, one of the main disadvantages of a canister filter is that there is less surface area for gas exchange.

Power Filters/Hang-on filters don't have this problem. The waterfall created from the output allows sufficient amounts of oxygen to diffuse into the water.

The airstones help greatly to create flow and circulate the water. And allows for more gas exchange when the bubbles pop/burst agitating the surface.

 

[sobersteve323]

Hello sober...

The oxygen in your tank is based on the stirring activity on the surface. The airstones produce more oxygen than the current equipment. If you take away a couple of airstones, you'll reduce the oxygen in the tank.

Once the tank is cycled and you add a few small fish, one airstone will be plenty. It would be a good thing to add some fast growing stem plants to the tank too. Once the plants are established, you'll have another oxygen source.

Just an FYI, you won't be able to have multiple airstones and a lot of plants too. Oxygen is a plant waste product and your plants won't survive very long in a high oxygen environment the airstones will create.

B

Thanks for the tips. Yeah, it's only going to be lightly planted so I'm keeping the air stones in there.

 

[sobersteve323]

Unless you have a spray bar, one of the main disadvantages of a canister filter is that there is less surface area for gas exchange.

Power Filters/Hang-on filters don't have this problem. The waterfall created from the output allows sufficient amounts of oxygen to diffuse into the water.

The airstones help greatly to create flow and circulate the water. And allows for more gas exchange when the bubbles pop/burst agitating the surface.

Thanks, this is exactly what I was wondering. I previously had a HOB on the tank but just switched it out for a Fluval. I was admiring how quiet and calm the surface was and then it dawned on me about the lack of surface agitation. I think I'll plan on keeping all of my airstones in there.

 

[Bubble_B0y]

Thanks, this is exactly what I was wondering. I previously had a HOB on the tank but just switched it out for a Fluval. I was admiring how quiet and calm the surface was and then it dawned on me about the lack of surface agitation. I think I'll plan on keeping all of my airstones in there.

I find a good combo is to have both the HOB and the canister running at the same time.
And the HOB is more effective than the airstones.

good luck

 

[eco23]

With my canister I just raise the output a bit and point it towards the surface. It doesn't break the surface (so it's quiet), but basically creates waves which give great movement on the water surface. I've never had an issue with low o2 exchange, no bio-film, no gasping fish, etc... The idea of air stones causing issues for plants is also debatable because there is co2 in the air around us, so there is co2 exchange at the surface just like o2.

I have added air stones to my tank recently, but it has nothing to do with aeration (since the canister alone works perfectly), but I use them as a safeguard in case my filter were to fail.

 

[sobersteve323]

I find a good combo is to have both the HOB and the canister running at the same time.
And the HOB is more effective than the airstones.

good luck

Thanks! I had thought about running both but decided against it since it was quite noisy (just a cheap TopFin). Going to run 2 HOBs on my 36gallon once I get it back up and running again though.

 

[sobersteve323]

With my canister I just raise the output a bit and point it towards the surface. It doesn't break the surface (so it's quiet), but basically creates waves which give great movement on the water surface. I've never had an issue with low o2 exchange, no bio-film, no gasping fish, etc... The idea of air stones causing issues for plants is also debatable because there is co2 in the air around us, so there is co2 exchange at the surface just like o2.

I have added air stones to my tank recently, but it has nothing to do with aeration (since the canister alone works perfectly), but I use them as a safeguard in case my filter were to fail.

I tried to copy your output from the last time we spoke and I think I'm in the same situation with rolling waves... minus the "white caps" lol. And the airstones in there originally were 100% aesthetic but now I'll pretend I have them in there as a backup plan also... haha.

BTW, I've been trying an "experiment" with my weird fishless cycle results (the ammonia not moving but I'm getting nitrites/nitrates). I'll post it tonight if it works after I get home to check, haha.

 

[mfdrookie516]

Air stones are not a bad thing in a non co2 injected tank. Often, they'll actually add co2 if you're heavily planted.

They are also not required. Your filter, if it's disturbing the water at all, will do plenty. It doesn't have to be above the surface. As long as the water is rippling, it's agitating it. Obviously, if you notice rapid gill movements, it migh tbe a good idea to raise up the outlet a little, but IME you can easily do that without creating noise.

 

[sobersteve323]

Air stones are not a bad thing in a non co2 injected tank. Often, they'll actually add co2 if you're heavily planted.

They are also not required. Your filter, if it's disturbing the water at all, will do plenty. It doesn't have to be above the surface. As long as the water is rippling, it's agitating it. Obviously, if you notice rapid gill movements, it migh tbe a good idea to raise up the outlet a little, but IME you can easily do that without creating noise.

Great info!

I guess I'll just wait and see after I get the tank stocked and then play it by ear then. I like to have a back up plan ahead of time so I'm not panicking when I hit a problem