# Canister Filters



## Rocko (Jun 11, 2006)

I read that canister filters, like the ones made by Eheim, are worthless for saltwater aquariums. Is this true? I bought an Eheim Professional II last year and I am wondering if I should sell it before I set up my saltwater aquarium. For reference, I am setting up a 75 gallon saltwater tank with live rock.


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## fishfingers (Apr 10, 2006)

Although not completely worthless, there are much better alternatives for the filtration of saltwater tanks (live rock, DSB, etc). I personally dont like them, some people do, but I beleive they are nitrate factories if they are used with the filter media that comes with them. If you want to keep using it you could fill it with LR, this would take some of the LR out of your main tank for a bit more space but this can be done easily with a sump/fuge anyway, both of which will benefit you a lot more than the cannister filter. I would sell it and get a bit of extra cash for the rest of your saltwater tank.


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## leveldrummer (May 27, 2005)

they help, but if not cleaned very frequently, they do produce nitrates. a skimmer is your best option for filtration, get a good skimmer, and youll be just fine.


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## Fishfirst (Jan 24, 2005)

You could use it for running carbon in the main tank, as well as some flow, but like level said, if they aren't cleaned a lot they produce nitrates... the reason nitrates are bad in marine aquariums but okay in freshwater aquariums is because in the ocean, there are hardly any nitrates in the water and fish and invertebrates cannot tolerate nitrates like freshwater fish can. High levels of Nitrates have been linked to hole in the head, fin rot and other diseases that can be a pain in the marine aquarium.


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