# Two filters...



## Kogre (29 Apr 2013)

I've been wondering about filtration and the layout of inlets and outlets for a few days.  I recently came across a "vs review" of FX5 vs Eheim Pro 3e (I think it was) which stated that the FX5 made a good mechanical filter and the Pro 3e had a larger capacity for bio media. 

Then I began wondering whether it was worth having a redundant filter and instead have two filters linked with one providing heavy mechanical filtration and the other providing heavy biological filtration, but linked under the tank to the outlet of the mechanical is linked to the inlet of the bio filter.  Flow rates differences would obviously cause problems, but has anyone else tried this?  If it's a big no-no I'd be okay with having inlets and outlets of each to the tank, just looking to minimise what is in the tank.  Any ideas that could relate to this?  Perhaps stick to the same filters if I'm looking to link them within the cabinet?

I know one of my filters is going to be an FX5, and for the other I'm thinking Eheim Thermo 2180 but the second filter is not set in stone yet; not till I've run it passed you guys, anyway.  

Also, where would UV filtration fit into this?  I'd like to have UV filtration but is it a necessity?  I'd sooner be safe than sorry and on a large tank I'd like to leave nothing to chance, but how have your experiences been with UV filtration?  Where would it be placed if there were two filters?  Is there nothing I can purchase inline as opposed to a filter?  I don't want a third filter running to the tank and don't really like the idea of flow rate being hindered by poor UV filter flow if it's running to a canister filter.

Any thoughts and recommendations are MORE than welcome!  

Peace.


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## greenink (29 Apr 2013)

Inline will result in massive reduction in overall flow. Which is why no-one does it.


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## Kogre (29 Apr 2013)

No suggestions for alternatives?

I've also heard that having two filters loaded with biological media can cause for competing colonies between the filters, which can also have a detrimental effect on water quality.  Can anyone confirm whether this is true?  If so I may stick to one mechanical and one biological filter.  If one filter fails I suppose I could throw the media from the failed filter into the other.


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## ian_m (29 Apr 2013)

I have seen UV sterilisers on separate pumped loops before (on display tanks in shops). They generally have had a monster filter, single inlet (say on left hand side of tank) to an "all the way across the back spray bar" and another inlet (on right hand side of tank) to an Eheim pump, to a UV steriliser and return to tank via simple pipe outlet.

This has the advantage that doesn't interfere with the filter flow and can use a pump match the UV steriliser rate. UV sterilisers have a "dwell time", the amount of time the water is exposed to UV and if your UV flow rate is too high the UV is ineffective.


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## ceg4048 (29 Apr 2013)

Hello,
		It's not really a good idea to port the outflow of multiple filters into the same conduit unless the conduit is enlarged to accommodate the flow. You really don't need to worry about what is biological and what is mechanical filtration. You will always have biological filtration no matter what media is in the filter.

Cheers,


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## Kogre (30 Apr 2013)

Great, thanks for the responses.

So I'm okay to have mechanical/biological across the two filters.

What do you all think about UV filtration?  Do you use it?  Is it worth having a seperate UV filter on a tank, upping the filter count to 3?!


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## ceg4048 (30 Apr 2013)

There's nothing wrong with UV filtration as long as it's on a separate low flow rate filter. It's one more complication that you can do without if you simply do large and frequent water changes, but that can get tedious as well...

Cheers,


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## dw1305 (1 May 2013)

Kogre said:


> I've also heard that having two filters loaded with biological media can cause for competing colonies between the filters, which can also have a detrimental effect on water quality. Can anyone confirm whether this is true?


No it isn't.

cheers Darrel


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## Kogre (2 May 2013)

If you guys had a large tank and had to run two filters on it, what filter(s) would you use?  Would you use different filters?  If so, why?

I've been reading up on FX5 and it eventually gets louder over time, even with regular maintenance.  If anyone has an FX5 and doesn't have these issues, pipe up!


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## greenink (2 May 2013)

Eheim 2078 every time. Basically silent, adjustable and solid as a rock.


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## Kogre (2 May 2013)

If you hadn't mentioned it I never would have known about it... That is a badass filter! Thank you for the recommendation.

I'll definitely be getting at least one of those. 

Does it have a drain feature for water changes like the FX5?


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## Alastair (2 May 2013)

i never suffered those noise problems with the fx5 but id opt for the eheim 2080 or 2078 if money isnt a problem.

neither have drain option though unfortunately . yu could buy so many feet of extra 16/22 tubing and the eheim connector taps and use the filter outlet tube to help drain the tank though


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## viktorlantos (2 May 2013)

I am more on that to drop all kind of filter mediums which isn't that good for bio filtration. Especially if you go with high light. Filter manufacturers do not care about your planted tank at all. They sell a product which works well for fish tank and basic planted tank. Even EHEIM lates filters has so many weak mediums in it. Plastic rings? come on! How that would do any bio work? Its nice you have a large filter bucket but if half of that filled with placeholder, do not have high hopes with high energy setups.

I do remommend to drop physical, and mechanical filter mediums and just keep bio ones. COuld be siporax, substrat pro, matrix etc whatever is easier to get. Keep the wool as that removes the fine particles and may add in a chemical filtration stuff like Purigen to keep your tank crystal clear.

The good thing is that you can change mediums on the fly anytime. But once you're in a high energy world with more light, then every filter tray will matter. That's my 2 cents


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## sciencefiction (3 May 2013)

Just looking at the ratings, but an Eheim 2078 or 2080 flow wise is rated way less than an FX5, so that should come into the picture too when selecting which one.


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## Kogre (3 May 2013)

So far then it looks like I'm leaning towards a 2078 and an FX5.  The tank is huge, at over 700 litres and will house discus eventually, but will 1850l/h of the 2078 and 2300l/h of the FX5 be too much for the fish considering discus like slower movement?


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## Alastair (3 May 2013)

The fx5 actual flow rate with media is around 1900 litres an hour and the 2078 about 1100. You can always knock the flow down on each if its too much


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## Alastair (3 May 2013)

Personally though from previous experience I ran a 2078 and 2080 along side one another and found the 2080 to give slightly more flow plus it uses less juice at only 25 watts. More media capacity too.


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## Kogre (3 May 2013)

Does the 2080 have an electronic timer for different flow rates like the 2078?


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## Alastair (3 May 2013)

no unfortunately, just a manual flow adjustor and indicator, but more media room and bigger capacity plus wheels to move it out ha ha


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## biffster (5 May 2013)

why do people think that plastic bio media doesn't work it does i have use plastic eheim bio media and used plastic bio balls both with good results the only problem i find with the eheim plastic ring media is that it floats but from what i have been reading over the last few months floating media is a good thing as its stops it clogging and also stops tracking the only other let down of floating media is that its noisy


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## Kogre (5 May 2013)

Who said anything about plastic bio media not working?


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## ceg4048 (7 May 2013)

Offending posts have been deleted. Kindly endeavor to stay on topic. Start a new thread on biomedia or whatever topic is desired.

Cheers,


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