# Internal Filter Help



## stupam

Hi, I've recently bought a 64 litre tank and also purchased a Hagen fluval u2 internal filter. I'm a bit lost as to which setting I should have the air flow. As I don't have an air pump would it be okay to have it set on the middle "spray curtain"? - I ask this because I was told that if I didn't have surface agitation I wouldn't be able to have enough oxygen in the water. Thanks in advance


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## hawksport

Unless your tank is over stocked I would leave the air venturi off. Gas exchange take place at the water surface, bubbles add very little. As long as your suface water is moving you will be ok


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## sheppy

U don't have to use to Venturi on the filter, just make sure that the water surface is being broken u will get good gas exchange


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## stupam

Hi, I've switched the venturi off & everything seems to be ok for now, Thanks for your help.


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