External Filters

[johnsmith]

Is it possible to run two same sized external filters in series to further improve bio/mech filtration in overstocked mbuna tank?

 

[RandyK47]

Sure it's possible but I'm not sure it's worthwhile. The first filter should take care of 100% of the mechanical filtration, at least in the sense that the "large chunks" will be filtered out. Unless you use even a finer media in the second filter I can't logically see where there'd be any further or significant mechanical filtration. Bio filtration would be increased but no more than if you ran both filters side by side, but not in series. IMHO you'd get more mechanical and about the same bio filtration from side by side operation.

 

[BigIan]

if you were going to run twin filters you may aswell wel run them seperatly,

if one filter fails, the other is still running

i was looking at running extra filtration on my tank. but i wasnt keen on the idea of having 2 outlets or inlets in the tank. but if you go to a plumbers merchants or even some decent tool shops they sell pipe connecttions that will fit the 14 mm silicone pipe.

so i would have bth filters running seperately but using a single inlet/outlet

 

[RandyK47]

Big - Good point about filter failure, I hadn't thought about that. I'd add that if one filter failed in a series hook up you could have a large mess. For instance, the second in the series fails but the first one keeps running. Depending on the filter you'd have the first one continuing to pump into a non-operating second filter. Unless it was a closed system I'd think the water in the second non-operating filter would overflow and the first one would keep pumping until the tank got below the intake....then of course it would run dry and you've potentially ruined that filter too. Personally I run two filters on both of my tanks, partially because I lean toward over filtration, but more that I travel and either tank could "limp" along with either filter running by itself.

 

[johnsmith]

Big - Good point about filter failure, I hadn't thought about that. I'd add that if one filter failed in a series hook up you could have a large mess. For instance, the second in the series fails but the first one keeps running. Depending on the filter you'd have the first one continuing to pump into a non-operating second filter. Unless it was a closed system I'd think the water in the second non-operating filter would overflow and the first one would keep pumping until the tank got below the intake....then of course it would run dry and you've potentially ruined that filter too. Personally I run two filters on both of my tanks, partially because I lean toward over filtration, but more that I travel and either tank could "limp" along with either filter running by itself.

By in series i meant in line, ie from tank to pump 1 inlet, from pump1 outlet to pump 2 inlet, then from pump2 outlet back to tank. This way i only have one set of out/in hardware actually in tank and double filter volume. I assumed that if one pump failed system would still operate albeit at reduced flow. The reason i want to do this is ive already bought ext filter and now realise could do with something bigger. As long as both pumps are same flow rate dont see why it should nt work

 

[RandyK47]

I don't see why it wouldn't work but still, other than reducing the hardware in and out of the tank, can't see that it would improve filtration, particularly mechanical. Having said that I also still wonder about pump failure. If the first pump fails then the second unit would be trying to pull water out of the tank through the first unit and all of its filter media then into the second unit and all of its media. Better minds than mine, or more experienced folks here, would have to address the potential of the second pump failing because of the load. Guess you could try it and see if it works. If the water seems to still flow easily then maybe no problem.

 

[k.o.d]

Eheim sell a through flow canister that does exactly what you want to do, basically it is a classic filter minus the pump head, this effectively increases the volume of the media by however big the canister is.

It is much more practical to run two externals in parallel in case one fails ( and I speak from experience here )
On one of the big tanks we run 4 1000 lph eheim externals in parallel
On the other we run 2 Eheim 2228's to back up the main sump, overkill I know but with the money we have invested in Asian arowana and stingray a decent life support system is a must.

Steve

 

[johnsmith]

Thanks for everyones comments , looks like its either running two in parallel thereby having the advantage of a back up incase of a pump failure, or the eheim through flow canister. Having thought about it could probably knock together some sort of through flow canister myself from some sticky back plastic and empty loo rolls! Anyone done it or have any ideas of what to use? What about one of those large old fashioned sweety jars with the screw top lids, two holes, some tubing, two valves, and bobs yer uncle.