measuring actual GPH

[shawmutt]

My Filstar XP1 filter is supposed to pump 250 GPH, but I'm being told that between filter media and position of the filter (about 3 feet under the tank) it's getting much less than that. Is there a way I can actually measure it?

Will this work? I could set my five-gallon water change container on a step ladder, and measure the time it takes to pump 5 gallons out of the tank. From there I could figure out the GPH. Is there an easier way?

 

[tkos]

http://saltaquarium.about.com/cs/beginnerscorner/a/aa081399.htm

I think that this article pretty much describes what you said. A long annoying but useful process.