Hi everyone,
I hear that cannister filters and bioballs are getting a beating
Well, for me to be devil's advocate means that I will stick up for good old fashion filtration on our cephalopod tanks and stick my neck out and say they do a fine job. But let me explain their place in all this...
We are not keeping reef tanks here. A cephalopod which is fed a healthy and varied diet is not a reef friendly animal for the average aquarium and is more than certainly classified as an ammonia machine.
They, by their very nature, produce a lot of ammonia, they eat a lot of meaty foods and they make a big mess while doing so. They also produce sucker disks by the bucketload! This is all anathema for a reef tank!
Many reef keepers these days, subscribe to such methods as Berlin, Sheng and others which rely on live rock being the only filtration in a tank with some skimmer action or sometimes without a skimmer altogether for the totally 'natural' tank. The tanks i set up last year are running on live rock only. No skimming, just live rock and hefty circulation and the odd water change. But then again, there is about 200 gallons, 150kg of rock and only about 15 fish.
The average lifespan of a reef tank is measured in years and in the long run, something which is producing a stack of nitrate is not welcome, so i wouldnt use a cannister or bioballs in a reef tank again. However, i certainly would in a large fish tank with messy predators.
The average cepahlopod tank has a lifespan measured in months and having such a large messy predator in a tank is far too much for liverock alone. In fact, I would suggest that after an octopus for example, has lived out its life in a tank, that it may even be best if the tank is stripped down and re setup before another cepahlopod is added???
If you are using bioballs the prefilter should ideally be washed on a weekly basis or at least while doing monthly water changes.
Unless you have a tank in excess of 200 gals and a stack of live rock, efficient skimming and good water movement i wouldnt stop using a cannister filter. Even it is in a mechanical fashion to physically trap and remove lrge dirt particles or in a chemical fashion as a place to house carbon or rowaphos etc.
I have ran out of time as i need to go to work this monring but any arguments or comments are welcome to help clarify all this
cheers
colin