les

Hi guys,

I have a 3 foot tank approx 150 litres (35-40 gallons).

Running an undergravel filter via a powerhead.

My question is how strong should the powerhead be ? I am using a 800litre/hour powerhead and I feel it may be a little too strong for my tank i.e. fish seem to have trouble staying still .. neons mainly.

Is there some sort of formula to follow ? i.e. how many times do you want the tank to circulate in an hour ?

This is a tropical tank.

Thanks.

Narcicius

I don't use undergravels for this very reason, sorry that I can't help you other than to reccomend a regular hanging external filter.

les

You are absolutely right. That wasn't very helpful at all.

EDIT

Found some more info on the web and in general turning over the aquarium volume 4 times an hour is fine. i.e. 600L/hour for a 150 litre tank.