I visited Steve last August or September to ask questions and then bought the same filter. I've been using it along with an 8 foot stock tank ever since then to grow out about 80 YP and 50 BG along with some fast and smart FHMs that have managed to not get eaten. I'm using a small seine net to separate the species.

The tank is in my shop which I keep at about 40 degrees, when I'm not working there. The water temp has been about 45 degrees for a month now. I have a very small amount of water trickling through all the time, probably only about 15 to 20 gallons a day. About once a week I change perhaps 10% of the water.

I can't tell you if the bio filter is working or not, but I do know the nitrates are never over 1%. I don't seem to see a lot of feeding activity, so they only get about a quarter cup a day of chopped shrimp and AM. I never see the perch eat, but they seem to be growing some. I do see the BG eat now and then.

I suppose that even if the water is too cold for the bio filter to work, the relatively small amount of organic matter going in along with the water changes keep the nitrates low.