using 2 cannister filters

[M0rph3us]

hi all i plan to use 2 cannister filter on my tank.. how shld i go abt doing it?
shld i have 2 outputs and 2 inputs? or
shld i connect the filter in series?? if so, which one to come first? and also both filters different flow rate and filter volume
how can i go about doing it without damaging my cannisters???

[roy]

I'm using three canister filters in my 5 ft. Two of the canisters will be permanent while the third canister is a temp added to help establish my new tank.

Anyway, it would be best to run the two cansiters independently, i.e. 2 ins and 2 outs. Connecting them in series don't make much sense since it's double filtration on the same volume of water. Whereas running the canisters independently allow larger volume of water to be filtered.

Presently, one of my canister has mostly biological media while the other has nothing but filtering media.

Cheers,
Roy

[Nicky]

Even though I do not have a double-filter-serial-setup, I think it is very useful and in fact I was contemplating using this type of setup for my 'dreamed' 6ft tank..

If you go to Sam Yick at Parkway and open the cabinet of the planted tank (not the ones upstairs but the one on level-1), you will see that the filter setup is 2x2250 in series.

I see lots of merit in this because with this setup, all the dirt and waste can be trapped in the first filter, with the second filter solely for biological filtration only. Only the first one need clean-out, if any.

The questions I have is if I were to setup something similar, do I need to operate the pumps of both filter or can I take away the impeller of the first one and let the second one drive the water flow? Or should it be the other way round, ie, let the first one do the driving?

[M0rph3us]

im also thinking which filter to turn on if i were to run them in series..
as for 2 inlet and 2 outlets i feel its kinda unsightly
wat do u guys think?

[roy]

Hmm... that's a tempting proposition. The series set up may be worth a try. If Sam Yick runs filters in series, it must be for a good reason.

Anyhow, I would think one pump would be enough. The more powerful pump would draw in the water and pump it thru the second canister. Impeller and pump on the second canister may be optional.

Having said that, running canister filters independently serve another important function, namely redundancy. I travel quite a bit for work and if one canister fails than the other would take over.

Redundancy is still achievable in series set up by keeping both impellers and pumps running. However, I worry it may damage the impellers and pumps. In an independent canister set up, inflow is "passive", i.e. drawn by the pump. In series with both impellers and pumps running, the inflow of the second canister is "pushed" by the first canister as well as drawn by the second own impeller and pump.

[vinz]

There is a thread sometime back in which LSZ gave a great reply to your questions.

[roy]

Morp, if you want to go for 2 ins and 2 outs, you should try experimenting the placements of the ins and outs. In my tank, I'm able to arrange them quite neatly.

I forgot to mention, one my canister is used with ... Urgh, can't remember the name. It's the thing aquarist use to suck the surface scum.

Cheers,
Roy

[vinz]

BTW, I'm running 1 Eheim 2250 on my 6 foot tank with a single input, but output split to 2. What size will your tank be Morpheus?

Roy, skimmer?

[David]

hi everyone

seriously, i dont see any advantage of having two filters that are connected as one. The purpose of having double filtration is to:

1. The posibility that when one filter fails and needs to be removed for repair purpose, there is still another canister to filter the water.

2. distributed water suction by having two inlet points (while one of them will usually be a surface skimmer) thus better removal of waste and prolonging in-between service of the filter.

3. better distribution of water circulation, especially if a internal CO2 reactor is used.

if two canister is combine as one in a series connection...would it not be easier to get the Ehiem pond filter and have an ehiem pump?

[Nicky]

My opinion:
If I am shooting for max filtration for not too strong a 'current' I will go for 2 filters connected in series.

[Allen_1971]

I'm currently running 2 filters in parallel... I am sharing the input, but having seperate outputs. Some points to note are

1. If sharing the input, make sure your input can supply enough water to handle 2 filters... I'm using a surface skimmer (taiwanese type) and initially, my skimmer was set to skim lots of water from the surface, and minimal amounts from the bottom. This proved to be inadequate, and as a result one my filters actually lost priming. Now I open my skimmer to maximum suction from the bottom.

2. Never link 2 outputs together. Even if your 2 filters are exactly the same model, chances are one will be slightly stronger than the other (due to dirt etc). By linking them together, you risk having the output of one filter drive water into the output of the weaker other filter... Again I learnt this the hard way...

[benny]

Hi Allen,

Is there a reason whey you would want to use only 1 intake/output for 2 filters? This would make the flow very strong. Also, wouldn't the additional intake/output be good for water circulation?

Cheers,

[Allen_1971]

The reason for linking the intakes is simple... less clutter in the tank. Too many pipes make it more difficult to hide.

As for trying to link the outputs, there were two reasons... firstly, like the intake valve, to remove some clutter... Secondly, my output valve connects to my dennerle cyclo 5000 reactor. I was hoping to increase the amount of water being injected, and by doing so (hopefully) improve the efficiency of the reactor.

[bclee]

More intake/outlets means more things to hide...


BC

[roy]

Yes, surface skimmer. Many, getting old liao! Thanks!

[David]

hi nicky

if you are shooting for max. filtration, would it not be cheaper to use a Fluidised Filter Bed and link it to the outlet valve of the canister or creating a 5 to 7 compartmental sump?

[DEA]

----------------
On 1/8/2003 9:06:08 AM

My opinion:
If I am shooting for max filtration for not too strong a 'current' I will go for 2 filters connected in series.
----------------

max filtration at low flow rate...
what is it that you want to achieve? full denitrification?
maybe you should consider what your aim is before deciding between the method you want to choose

if given a choice between using 2 filters in series or parallel, i'd do parallel
i doubt any tank needs that kind of filtration, especially not a planted tank
my filter is more to provide current and clean up floating detritus
in which case i would like to have twice the flowrate
i trust my plants for the rest

[untouchables]

----------------
On 1/7/2003 11:23:15 PM

I'm using three canister filters in my 5 ft. Two of the canisters will be permanent while the third canister is a temp added to help establish my new tank.

Anyway, it would be best to run the two cansiters independently, i.e. 2 ins and 2 outs. Connecting them in series don't make much sense since it's double filtration on the same volume of water. Whereas running the canisters independently allow larger volume of water to be filtered.

Presently, one of my canister has mostly biological media while the other has nothing but filtering media.

Cheers,
Roy

----------------

ur media configuration doesnt make much sense if u r connecting them separately. this config is best for in series connection although i personally prefer it to be separate cos u can then do alternate filter cleaning. odd month clean filter a, even month clean filter b. that way, u dun have to worry about drastic loss of biological filtration.

[vinz]

If you want a bigger filter capacity, get a bigger filter. Eheim has the 2250 and 2260 which are generally used as pond filters.

Some specs:

      Pump      Filter
      Output    Volume
      --------  ------
2028  1050 l/h  7.3 l
2250  1000 l/h  12 l
2260  1900 l/h  18 l

The disadvantage is that 2250 and 2260 do not come with any media baskets, so you have to use net bags to separate the media. I would guess that the 2250 is much cheaper then two 2028s.

2 outlets will distribute the output current, so you'll (a) get better circulation, and (b) not have a really strong current at one end and a much reduced current at the other.

2 well-placed inlets will result in a more uniform uptake of water into the filters.

[vinz]

When you connect 2 filters in series, you have to turn off one and remove it's impeller. Effectively, that filter becomes a very expensive media basket... unless you have an old broken down canister filter which is still water-tight.