Questions Bout Canisters

Why does everyone seem to hate on canister filters? does any1 got love for them? do canisters filters really deserve alot of bad rep that they get?

 

They are awesome filters for many things, but for reefs, which most the tanks on here are, they really are not a good solution. Freshwater fish and most salt water fish are ok with some nitrates in the water, so canister filters work fine for them.

I run one on my freshwater tank, but I would never try it on the reef.

 

but with a combo of a good protein skimmer wouldnt it keep the water quality prestine?

also my lfs has a canister on one of their display reef tank and they been having the same corals in there for the past couple of years!

 

a skimmer will not pull out the nitrates and phosphates to the extend that a canister will replenish them- im going to just run phosguard and carbon thru mine when i re- setup my tank

 

Only, only if you keep your media fresh. I change my floss every other week, no later. I change my Chemi-pure Elite every month. I clean the head and tubes monthly. My canister is also oversized for my tank size. In other words don't use it for biological filtration.

 

so what causes the nitrate factory? im currrently runnin the floss ceramics bio balls carbon...

 

Nitrifing bacteria grow on the media in an aerobic environment eventually creating nitrate. Nitrate breaks down only in anaerobic ( no or very low oxygen) conditions. Hence the term nitrate factory.

 

I think sometimes the term nitrate factory may get over/mis-used. To me anything that produces nitrate and also doesn't denitrify is a nitrate factory in that it can produce positive amounts of nitrate.

Here is my understanding of it. With canister filters, which I agree are not necessary for reef tanks, you have a lot of oxygenated water flowing through a system which generally has lots of surface area, a prime situation for nitrification (ammonia > nitrite > nitrate). This makes an efficient biofiltration system generally but in reefs where people generally have lots of rock and sand this is not usually necessary because the nitrifying bacteria will populate the sand/rock.

On top of being good places for nitrifying bacteria there is also commonly a place in the canister where uneaten food/detritus etc can collect and continue to break down, thus producing more ammonia. If properly maintained you can get by with cleaning the filter on a weekly basis and not have too much stuff get trapped there. If the uneaten food/detritus was left in the water column (and your system has enough flow and is properly maintained etc) it would be skimmed out or eaten by detritivores and cleaners (bristle worms, brittle stars etc) and broken down further.

So canister filters basically setup ideal conditions for producing lots of nitrate, not converting that nitrate into harmless nitrogen gas, which generally relies on low oxygen areas within the rock or sandbed, or some other system like using a refugium or carbon dosing etc.
This is the basic reason why I think canister filters are unnecessary in reefs, there is already enough "media" in the rock and sand to easily handle the ammonia produced so adding a canister filter is just more stuff to maintain and worry about. If you want to run carbon or GFO or something for chemical filtration, I would suggest something simpler like a reactor from bulkreefsupply or something that you can place the feed pump after your filtration in the sump so it won't pick up as much junk and generally is better designed to not trap as much stuff, and is also easier to maintain (I think anyway), although you do still have to maintain the reactor of course.

My 2c

 

I took all the ceramic rings and such out of my canister filter and replaced it with carbon and Bellaphos and am essentially using the canister filter as a large media reactor, running both media at the same time.

 

so whats the benefits of that