Canister Filters an SW Tank

[InfernoST]

Hi Everyone
At the moment I'm Cycling a FW tank and am looking forward to putting together a SW tank in the future and have a couple of questions regarding filter types. I've always been a long time fan of eheim canister filters and wanted to know if they are OK to use with a SW tank? Personally i feel more comfortable with a closed system (Power failures aren't as big of a problem with canister filters) as opposed to the open wet/dry filtration systems. What are the advantages and disadvantages between the two types of systems?

Thanx Everyone

 

[pat8you]

People have had successful tanks with canister filters but they are not very well suited to SW in my opinion. It is going to depend a lot on what kind of tank you want to set up. SW tanks with coral are going to need a lot of flow. It is recommended to have 10x turn over rate or better. It can be difficult to provide that with a canister on anything except a small tank. A good canister provides three types of filtration. (btw i'm just starting with basics i do not mean to insult if you are a more advanced hobbiest.) First is mechanical, which is usually in the form of a sponge that catches particles. In salt and fresh this will collect a lot of garabge and can easily contribute to high nitrate levels if not religiously maintained. Second is your chemical, this is where a canister really does have some application. It is an easy place to run which ever kind of media you wish (phosphate, carbon, or others in unusual cercomstances). Last is your biological. There really is no need for additional biological filtration in a SW tank because your live rock and sand bed will provide more then enough surface area for the benifical bacteria to grow. So when it comes down to it, to me anyway, a canister filter is really just a pump with the option of running media conviently.

I would rather see a sump/refugum combination. It will provide space for equipment, nutrient export via the macro, and additional water volume. Running media is not difficult to accomplish either. As far as power outages, this is an easy problem to fix. When you set it up, you unplug everything and then top off the sump to just below the rim. Then plug everything back in and mark the water level on the tank. This is your max water level for the sump and then if the power ever goes out you are positive that you have enough room in the sump to accomidate the additional water.

This is just a ruff outline though. Depending on the type of set up you want this can be tailored to best suit your needs. I guess the shorter answer would be that in my opinion i don't think canisters have much application in SW.

 

[CaptainAhab]

Take the sponges out, use LR rubble in some of the chambers. Use the others to run media when you have to. There are plenty that don't want the expense or fear of a flood that use a canister (or 2 or more) just fine. Drop Roka64 an IM. He'a a devout user. Actually, I use both a sump and a canister.

In the end you could just use LR and a HOB skimmer and be successful. Adding the can to that mixture makes it even better.

 

[Drewbie]

I just had a wonderful conversation with a gentlemen who told me he runs 14+ tanks using filters and chemi-pure no sumps no skimmers and swears he has had zero problems

also claims his tanks are heavily stocked.

As long as you stick with your water changes have lots of live rock some some power heads you will do great I am sure.

 

[InfernoST]

Hi All
Thanks for all of your input, however I'm confused about one thing. If the sump system is not actually a filter does that mean one would have to have 10 to 14 times tank capacity in water movement/circulation?

 

[melosu58]

Alot of sumps are a filter because they will have a filter media in it that will host the beneficial bacteria in it that runs the nitrogen cycle. Actually IMO LR and a skimmer is all you really need.

 

[CaptainAhab]

Adding on to M; however if you already have a canister laying around, it would add extra flow and a place to run alternative media when you needed or wanted to. Like carbon, purigen, GFO, etc or even switched to a QT tank in a jiffy (do that w/ your sump). If you have it; use it (minus the sponges). If not then it's a personal decision. Both sides have been pretty well laid out here.


If I read your final question right, figure flow based on your display not including the sump BUT include the return GPH in your total flow calculations. Clear as miracle mud?

 

[roka64]

I love my cannisters. I use Fluvials, but I hear eheim are great ones too. I really don't consider my filter in the equation of water flow. Depending on your coral selection, you will need different flows. Personally, I like the Hydor Korelias for water flow. In SW you want some surface ripple for proper O2 exchange (in SW, it happens at the surface).
I really only run LR rubble and purigen in my filters and the first thing I do when I get a new filter is take out the sponges.