"I have numerous tanks and sizes throughout my house - ALL of them are setup with Marineland Biowheels. These tanks have been operating for at least 10 years! You can't get any better filtration and water clarity. Plus, I can't even remember when I had any kind of nitrite or ammonia problem, at least not since before I used Marineland filters!
Let me give the people who have had any kind of problems a few hints:
a) If the filter sounds too noisy to you:
Add water! If your water level is too low, you are going to notice the splashing is louder....gee, who'da thought? And, you might even hear the mechanical sounds of the filter instead of the sooothing sounds of a gentle water flow.
b) If the biowheel isn't spinning properly:
Take it out and check for a mineral buildup around the ends. I recommend using water without a high mineral content which is better for the fish anyway. Also, make sure you keep any live plants trimmed down to a manageable level, and pick out any floating leaves, etc.
c) If you find that (in a duo biowheel) one of the biowheels is acting up, just change one of them at a time. That way, you still have all of the beneficial bacteria from the old one until the new one can build up.
d) I DO definitely like using the charcoal medium in the baskets as well as the pads. By doing this, just add water whenever your level gets low, and all you will need to do is a monthly cleanup.
d) Monthly cleanups are simple: just lower the water level, change the charcoal and the pads, add clean (no tap or high mineral content) water, check the biowheels for any buildups on the ends, clean up any debris like plant mess, etc. And clean your intakes. That simple.
I have very seldom had to replace any parts in the 10 years these filters were running - which is more than you can say for the other filters out there. What more can you ask for?"