Fluval internal filter question.

[oldbloke]

I have just bought one of these for my quarantine tank Fluval Mini Underwater Filter 200LPH: Amazon.co.uk: Pet Supplies and the instructions state the outlet must be situated below the surface of the water. I was hoping to set it a little above to provide aeration.

Can anybody think why it has to be like this?

Cheers.

 

[oldbloke]

Sorry, problem sorted.
According to Fluval, it does not have to be set below the surface.
Which beggars the chuffin question....................

 

[Mike Edwardes]

If it's too high out of the water you may find it sucks air and is noisy (this also wears the impeller over time). I've often used a couple of 90 degree elbows connected by short bits of tubing with internal filter of this sort to allow the outflow to break the surface (death to all surface scum!).