Misadvertised Flow rates of filters

[Talleyrand]

I have a 55 US Gallon tank with a Regent 330 gph power filter. I have had several problems with disease in the tank and have suspected that I needed more filtration.
I just purchased a second power filter, a 200gph (760 liter) Marineland filter, with supposedly less than 2/3's the pumping power of my original filter, and its clearly outperforming the 330.
As soon as I filled the filter up and plugged it in, eddies of detrious started whirling around the bottom of the tank. The older filter never performed that well.
I realize the larger filter is used and starting to wear, but compared to the 200 it must be pumping about 150 gph, maybe.

 

[freddyk]

Yup, age will slow a filter down. The truth is though, all filters are misadvertised, as they measure the flow rate with a perfect conditions, empty filter.

 

[BobK]

Hey Tallyrand, did you get your tank and filter as a combo at Walmart? Just curious. I got a 10 gallon combo from there with a Regent Aqua-Tech filter. I've never seen a Regent filter anywhere else. If not, where did you get the Regent filter?

 

[Talleyrand]

Yeah, I bought it at WalMart about two years ago.