The Fluval 107, 207, 307 and 407 is designed to pump water. If you see that your performance canister filter keeps pumping out a lot of micro air bubbles instead, then you can take a look at this troubleshooting article from Aquarium Blueprints.
1. The first step you can try is to manually prime water into your canister.
In order to do so, you need to take the following steps:
- Unplug the filter from the power outlet in order to turn it off.
- Afterwards, make sure that the AquaStop valve has been pushed all the way down for the priming process.
- Next, grip the instant-prime handle.
- You then need to pull the handle all the way up and before pushing it all the way back down.
- Repeat the same process until you only see water coming out of the output nozzle of your filter.
- You can then plug the filter back into the power outlet in order to turn it back on again.
2. If your Fluval 07 Series canister is still pumping out a lot of bubbles, then you can inspect the intake assembly and hosing to make sure that these are securely attached to the rest of your filter.
3. Of course, you should also make sure that the top of the canister is also properly sealed so that no air will be getting inside.
4. If you are using an air stone or bubbler, then the bubbles produced by these devices may be pumped into your Fluval 107, 207, 307 or 407 canister.
In this case, we recommend moving the air stone or bubble to as far away from the filter intake as possible.
5. If you are recently added new filter media, then these may be the cause of the micro bubbles being pumped out of the canister.
In a vast majority of cases, these bubbles should go away very quickly on its own as the media gets waterlogged. If bubbles still remain, then you can try replacing the filter media with a different product to see if you can get a different result.
6. There is a possibility that the bubbles coming out of your canister may not be related to your filter at all.
If you are using a liquid plant fertilizer, medication or any other products, then these may result in a lot of bubbles being produced.
Therefore, there is not much you can do other than to stop dosing the liquids if you want to prevent the micro bubbles from appearing.