# Fluval 406 filter



## DIRTYFACE12 (Mar 16, 2015)

I DNT HAVE A fluval900 but ...I have a 406 fluval canister filter on a 75 gallon tank and im trying to find out how often should I change carbon bags ?


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## Deeda (Oct 12, 2012)

Hi and Welcome to C-F!

You don't need to use carbon in your filter on a regular basis but if you want to use carbon, just follow the recommendation in the filter manual. I think the average suggestion is 6-8 weeks but I'm not positive.

Carbon is usually used to make the water clearer or to remove medications after treatment.


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## richraceri (Mar 3, 2013)

I use 406's in combination with Aquaclear 70's. Once a month is about right for me, but it depends on your specific conditions. I usually raise the glass hood and take a smell up close. If it smells fishy or wife complains she can smell tanks change the carbon. The more algae you let grow the faster this can happen. Also a missed dead fish creates smell fast. The trick is to buy media bags about 4" by 10" fill them with the same amount of bulk carbon as Fluval sends and knot them off. Cheaper then zipper bags, faster then strings. Surprisingly the single carbon bag in the Aquaclear works almost as well suggesting 4 bags of carbon in the 406 is wasteful, probably 2 is more like it. I tend to think 2,4,6 bags doesn't buy you 2,4,6 weeks of good smell. It seems to become ineffective at about the same rate no matter how much you use, so more (volume wise) doesn't seem to buy me as much as more frequent changes. I change water every week (30%ish), clean the heavily stocked 90 gal tanks every 2 weeks (power wash or cook rocks to reduce algae) and alternate filter cleaning so they end up being cleaned once a month, filter rinses always in tank water. The filters could go alot longer between rinses but this pattern I've been using for years and my tanks never smell, always crystal clear. 
PS: Keep spare motors ($35 motor kit for 406) as the motors in both filters rarely last over 2 years, but replacement restores the filter to perfect.


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## hisplaceresort1 (Mar 10, 2014)

agree... everyone thinks their tanks don't have a smell, but if you get up close, you can usually tell zero odor from just a little bit. When you can start smelling anything at all - change it. 3 weeks for me.


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