# ?Running a Second External Canister Filter Inseries/Inline?



## tom_m2k (28 Feb 2010)

:idea: Question...

Has anybody ever tried to run a second canister filter inline (in series) to the main filter?!

I am of the opinion of maximum filtration volume, but i like to keep minimal equipment in my tank. I want to increase my filtering capacity in my main 130L tank. I currently use a Tetratec EX1200 canister filter with the normal media insitu. I then use external filter to supply the water to the trickle filter built into the tank's lid. This current setup keeps the water crystal clear, however i wish to start using a CO2 system. As i understand it, the trickle filter would greatly decrease the CO2 level. 

Assuming this is correct, i have been thinking of buying a second EX1200 and running it in a series - as opposed to parallel ! 



Water from Tank ---------> First External Filter ---------> Second Filter -----------> Filtered water Returned to tank



I propose to do this by connecting the outflow from the first filter to the inflow of the second filter, thus removing the need to use the trickle filter. This would mean that i would maintain high CO2 levels during the day etc etc... 

Do people think this would work!? Would both pumps work at the same speed or would there be an issue with supply and demand!?

Any thoughts would be good!

Cheers

Tom


----------



## Steve Smith (1 Mar 2010)

It may work, but you would be doing yourself out of a good way to distribute flow, using two outlets postioned in different places in the tank.  You may also find that, as the first filter clogs up and the flow decreases, the second filter strains to pull water from it.

I know this has been discussed before on here.  Have a quick search around to see if you can find previous threads


----------



## Ed Seeley (1 Mar 2010)

As Steve said why not just run two filters in parallel?

If you run them in series you won't be able to balance the flow as one will always pull more than the other.  Trickle filters are excellent but a real no go for a tank with CO2 injection unless you add huge amounts of CO2 to offset all that will be gassed off by the trickle tower.  If you can use the media from the trickle tray in the new filter to reduce the time it takes to mature.


----------



## tom_m2k (2 Mar 2010)

I agree with both your comments - its just been an idea floating in my head - something which doesnt happen very often!

My concern with my current set up is, as Ed said, CO2 injection. Ideally i want to remove the need to use the trickle filter so i can introduce a CO2 system. however because the current two filter set-up works so well and maintains top quality water, i want to find a suitable alternative. 

Flow distribution is not really an issue because i have an extra powerhead in the tank which seems to keeps the flow high through pritty much all depths (the tank is about 720mm deep).

In agreement with Steve, the first filter clogging would obviously hinder the second inline filter, thus putting it under unnecessary strain. I wonder if using the first filter as mechanical only and cleaning it more often would reduce this? leaving the second filter with biological media only (carbon etc). 

However i am only using this as a sounding board and am obviously open to positive/negative ideas! I have been offered a second filter (EX1200) which has a faulty pump. perhaps this could be used as the first media "storage", relying on gravity to siphon the water from the tank, leaving the second working filter to pump the water back to the tank....

Tom


----------



## Steve Smith (2 Mar 2010)

You mean like this? 

http://cgi.ebay.co.uk/Brand-New-1-5L-Ex ... 3a4a907190

If the EX1200 was cheap, then might be worth it.  If it's within 3 years old, you may well be able to get Tetratec to send you a replacement head for free.  There customer service is very good, and doesn't ask a great deal of questions.


----------



## tom_m2k (3 Mar 2010)

*Re: ?Running a Second External Canister Filter Inseries/Inli*



> http://cgi.ebay.co.uk/Brand-New-1-5L-Ex ... 3a4a907190



Yes, my idea exactly!

Has anyone used one of these? Those "outside tape" push fits look abit hazardous do they not...!?


----------



## gzylo (6 Mar 2010)

*Re: ?Running a Second External Canister Filter Inseries/Inli*

Hi Tom

I am currently running fluval 405 & 405 together in line (both are around 1300lph)same spec different box.I have not managed to get any problem because of that apart from priming. make sure both of filters are full of water including inlet and outlet pipe .

as for flow - I am using in-line co2 reactor with spray bar along whole length of back wall.

Thanks


----------



## Garuf (7 Mar 2010)

*Re: ?Running a Second External Canister Filter Inseries/Inli*

Forgive my ignorance but doesn't this just cancel itself out? Surely adding 2 lots of 1300lph together but sticking them inline means they're only working at the nominal rate of 1300lph and entirely negates the reason for having two filters, that being increasing flow?


----------



## flygja (7 Mar 2010)

*Re: ?Running a Second External Canister Filter Inseries/Inli*



			
				Garuf said:
			
		

> Forgive my ignorance but doesn't this just cancel itself out? Surely adding 2 lots of 1300lph together but sticking them inline means they're only working at the nominal rate of 1300lph and entirely negates the reason for having two filters, that being increasing flow?



I was thinking the exact same thing. If increasing flow is not the requirement here, then going with that pre-filter is a better idea I think.


----------

