# Bio balls in filter (replacing A.C.)



## adamxatomic (Oct 6, 2011)

I have a Fluval C3 HOB filter on my 20L goldfish tank. I saved the A.C. and instead put bio balls in the cavity that the A.C. normally goes in. My question is, are the bio balls doing any good, or should I take them out? I also have a DIY moving bed filter with about 1/3 liter of media (straws for now, K1 soon).

Thanks for any help/ suggestions.









*(Water not cloudy. Glass is dirty because I have a 2yr old that likes to "touch" the fish.)*​


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## lohachata (Jan 27, 2006)

if by " A.C. " you mean activated carbon....if it has been in use for more than a couple of weeks throw it out..it isn't any good any more...the bio balls are fine..will keep your bacteria levels up where you want them...

hmmmmmmm...i do believe i see baby smudgies all over the fishies....lol


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## ILLBETHEJUDGE (Apr 18, 2012)

Activated carbon is only good if you are trying to remove medications, There is so much discussions about benefits of activated carbon but IMO is only good in some cases but not necessary.
Also there is no need to replace the filter media, just rinse it with aquarium water to clean the debris and put it back.


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