I'm looking at getting a new filter, but I need to know how many litres/gallons per hour would be necessary for a 3 foot tank (100 litres approx)?
Thanks!

100 liters is roughly 26 US gallons. So, you'd need a filter that
would do 260 gph (gallons per hour) minimum. A Emporer 280
or a penguin 350 will cover that just fine. Both of those are a
Marineland product and have the biowheel.

I just got a penguin 350, would highly recommend it, the new design is great and the bio wheels are huge. Go for as much filtration as you possibly can.

Just my 2 cents worth

Ok thanks for the help guys!