Changing GAC cartridges in Penguin 200

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Aquarium Advice Apprentice
Jan 30, 2007
How often should I do this. I have been reading a lot about the bio-wheel and little to nobody on this site recommends them but I do not have a skimmer yet. The tank (15G) has been setup for two months now and has had two cartridges in the filter since day one to boost and help maintain a beneficial bacteria bed. I am pretty sure it is almost time to change them but how often should I do it after I get in the process of switching the cartridges?
GAC is only good for about a week (I believe). I don't run it in my tank, unless I need to. The biowheel can become a nitrAte factory. Folks like to replace them with LR rubble.
Moved to Hardware/equipment forum:

The beneficial bacteria is housed on the wheel not the pads. The GAC pads should be changed
roughly every two weeks depending on bio-load, feeding, and how dirty they get. You may need to replace it weekly.

The reason most people don't like bio-wheels (myself excluded) is because typically people don't clean there filters often enough and the waste builds up and easily converts to no3 which is why people call them "nitrate factories".

If you clean/replace your filters frequently you shouldn't have issues.

If you have enough base/lr in the tank 1.5-2 lbs per gal then you could do away with the wheel once you get your skimmer.
I replace mine every week on my Seahorse tank. As Micah said it really goes by your bioload.
I've got a Penguin 100 running on my 46g, just to have a "seeded" filter to switch over to my QT. I run the blue GAC pad along with the BioWheel. I rinse the blue pad really well in my "old" water every week when I do a PWC. I change it out completely after 4 weeks. I also run GAC in a HOT Magnum250, so I'm not overly concerned about the little amount of GAC in the Penguin filter not being any good after a couple weeks. I'm mainly keeping the blue pad in there to make sure food/poop/gunk doesn't flow across the biowheel and pile up on it. Nitrates are at zero, but my bioload is pretty low - just a clown.
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