# Too much filtration?



## PBM3000 (8 Aug 2017)

We always hear "you can never have too much filtration".  However, I'm beginning to suspect that I am indeed over-filtering my 240 litre box.

I'm running an Eheim 4e+ 350 _plus_ a Fluval 306 which, as I understand it is way more than enough.  My issue is that I'd like to have floating plants and the flow from both together just smashes them up and they rot real quick.

Do you think I'm over-filtering and could I safely 'downgrade' to just the Eheim (saving power, too)?  I'm moderately concerned that removing the 306 may cause a temporary overload for the Eheim - so I might do a few more water changes.

My UV steriliser is being decommissioned, too...

Any thoughts?


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## kadoxu (8 Aug 2017)

From my understanding, too much filtration and too much flow can be 2 different things...

Too much filtration means you won't provide the bacteria in the filter enough ammonia/nitrites to have a healthy sustainable colony, meaning that it becomes harder for the bacteria to quickly deal with ammonia/nitrites spikes.

Too much flow on the other hand, will blow everything with it... and it's usually easy to manage.

Your setup seems to be just fine. The rule of thumb is for the filters to pump your aquarium's water volume 10x per hour, so a 240L tank would need a 2400L/h output. The EHEIM 4e+ 350 works at 1500L/h and the Fluval 306 works at 1150L/h, a 2650L/h in total (and these numbers from manufacturers are usually debatable, to say the least), so you're not that far from what you should have, which means you just need to work around the amount of flow.

I run a EHEIM Classic 250 in a 19L Fluval Chi tank myself with no issues so far. I only had to deal with the huge amount of flow it had.

If you have a spray bar, you can open it's holes a bit more, or even open a few more holes on it. Also, pointing the holes upwards may help you reduce flow, but I'm not sure if this helps with the floating plants.


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## PBM3000 (8 Aug 2017)

I've been chewing hard over this since I posted and I'm now leaning towards _not_ taking it out. I installed it as an extra mechanical filter to take the load off the Eheim and it worked to a large extent. It certainly reduced cleaning intervals. I've probably lost sight of this. Particles do my nut in!


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## Zeus. (9 Aug 2017)

kadoxu said:


> Too much filtration means you won't provide the bacteria in the filter enough ammonia/nitrites to have a healthy sustainable colony, meaning that it becomes harder for the bacteria to quickly deal with ammonia/nitrites spikes.



Been thinking about this a little and i cant see how too much filtration can make much difference.

  Say you have enough bacteria in your filter, which is constantly growing and shrinking in numbers dependant on your tanks needs or just going slightly dormant Then you increase the surface area by say time times all you will do is give the bacteria more places to live, the bacteria will respond the same to any changes in biological load as long as there is enough surface area for them to expand. So IMO the biological filtration will remain unchanged except your total biological filtration capacity will be higher so will be able to cope with a higher load if the need arises.

As to the mechanical filtration the more you have as long as flow is good is not bad either as it will take longer to clog up IMO, regular cleans are always better but having a filter which needs cleaning less can be a good thing at times as well IMO


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## kadoxu (9 Aug 2017)

It's only my opinion... I have found no scientific evidence to back it up, but it makes sense to me.


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## gex23 (9 Aug 2017)

Sorry to interject but I have a question regarding this topic and didn't feel it needed a new thread (if it offends i'll remove my posts)

10 x flow means on my 90 litre tank I need a 900 litre water turnover - my Eheim 350 claims 1050 LPH which should be enough, but with a head height of 90cm I do wonder what my actual turnover rate is? Should I add another external filter maybe?


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## jon nash (9 Aug 2017)

gex23 said:


> Sorry to interject but I have a question regarding this topic and didn't feel it needed a new thread (if it offends i'll remove my posts)
> 
> 10 x flow means on my 90 litre tank I need a 900 litre water turnover - my Eheim 350 claims 1050 LPH which should be enough, but with a head height of 90cm I do wonder what my actual turnover rate is? Should I add another external filter maybe?


what size tank and bioload ie fish stock do you have


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## dw1305 (9 Aug 2017)

Hi all, 





kadoxu said:


> I have found no scientific evidence to back it up, but it makes sense to me.


I think it is quite a reasonable video, it isn't my style of fish keeping, but for people who want to keep fish in non-planted tanks he is probably quite a good reference point. 

I would disagree with idea that the "bacteria" can't grab the ammonia as it goes by if the flow is "too fast", it just isn't true. It would make more sense if he talked about "denitrification", because in that case you would need a longer dwell time to de-oxygenate the water before anaerobic denitrification occurred. I'm not a fan of denitrification in a filter, and we have plants to take up the NO3. 





kadoxu said:


> From my understanding, too much filtration and too much flow can be 2 different things...
> 
> Too much filtration means you won't provide the bacteria in the filter enough ammonia/nitrites to have a healthy sustainable colony, meaning that it becomes harder for the bacteria to quickly deal with ammonia/nitrites spikes.
> 
> Too much flow on the other hand, will blow everything with it... and it's usually easy to manage.


You are right, he is equating flow with filtration, and they aren't the same thing. He alludes to the differences between mechanical and biological filtration, but he doesn't really explain that they are separate processes. You can have massive biological filtration capacity without any laminar flow, particularly if you use an over-tank trickle filter.





PBM3000 said:


> I installed it as an extra mechanical filter to take the load off the Eheim and it worked to a large extent.


I would recommend not using your filter as a syphon, I like to have all the mechanical filtration in an easy-clean pre-filter on the intake, it just makes life easier.  

At about three minutes he says that he keeps bare bottom tanks, and in this video you can see the entirely bare tank with an Arowana in it.



cheers Darrel


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## zozo (9 Aug 2017)

In the first video he says you can have a to big a filter regarding biological filtration, in relation to food offer and bacteria population.. ?? I also can't see this happen..  Where ever the food is in highest concentration the bacteria population will be highest, where ever in the filter this may be obviously that where the biological filtration will take place, this will like be very short after the spot where the dirty water hits the media. So all media there after not getting any food will simply function as mechanical filtration as log as it's shape allows it to.

The same happens in nature all around us.... E.g we have a subterranean river running through a landscape which is mainly compossed out of a huge dozens of metres deep sand plate  with a loess soil top layer or what ever top you want.. We have them, tho you don't see, it's subterranean, we call it ground water.. Somewhere along the route of this water way seeping through the sand is a huge hole in the ground as large as a small lake. That's the place this subterranean water stream surfaces, the water comes from one end and goes on subterranean at the other end on the the next hole in the ground or maybe turns into a little superterranean river. The water is pottable quality the lake is teeming with life, because it runs through a huge plate of sand for miles and miles before it reaches that hole in the ground. That sand plate is an enormous natural mechanical and biological filter system? Isn't it?.. We are talking miles and miles of sand, where the hell would this be to much??

I got such a lake and subterranean river 500 metres behind my house.  i know it comes from Germany through the same sand for over 20 miles, but i actualy do not realy know where it exactly runs to, it likey pops up near some river up north, which actualy is down from my perspective..


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## dw1305 (9 Aug 2017)

Hi all, 
I think he is partially saying that you can save money by not buying "extra" filtration from a larger filter.





zozo said:


> In the first video he says you can have a to big a filter regarding biological filtration, in relation to food offer and bacteria population.. ?? I also can't see this happen..........


You are right, and your ground water analogy is a good one. <"Gravity fed slow sand filters"> are used a lot to improve the quality of drinking water in countries without a central infrastructure. 

You can never really have too much potential biological filtration, if you have a large oxygenated surface area available for biofilm development, an assemblage of microbes will grow on it, they just form a very thin layer, because their growth is limited by the availability of carbohydrates, fixed nitrogen etc. Same happens in the substrate there will be a population of microbes, from aerobic to anaerobic, at different levels of oxygen, carbon etc availability. 

As you add nutrients the relative composition of the assemblage will change, but it will remain diverse and resilient, with a central core of nitrifying organisms. 

This is described in <"Freshwater Recirculating Aquaculture System Operations Drive Biofilter Bacterial Community Shifts around a Stable Nitrifying Consortium of Ammonia-Oxidizing _Archaea_ and Comammox _Nitrospira"_>. 

I knew that you could take very polluted water (landfill leachate) and then use a combination of high rates of oxygenation and plant/microbial filtration to drastically reduce the level of pollution. 

From there it was a short conceptual jump to you could use exactly the same principle to create really clean water from a lightly polluted supply.

cheers Darrel


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## PBM3000 (9 Aug 2017)

> I like to have all the mechanical filtration in an easy-clean pre-filter on the intake, it just makes life easier.



I tried that.  Every time the filter was switched off, all the detritus just fell off and re-polluted the tank.


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## PBM3000 (9 Aug 2017)

Who runs two canisters on their tank?


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## Zeus. (9 Aug 2017)

DIY king says 'Contact time isn't enough for the bacteria to pick up the ammonia if flow is too fast ' The flow over the surface of the mechanical and biological surface will be relatively the same in High or low flow eg very slow, it will be faster in the open spaces OFC  In the biological media itself it will be slow also. So as 'Contact time isn't enough for the bacteria to pick up the ammonia if flow is too fast '  I would say 'BS' Bacteria thrive in very very fast rivers they are masters of their trade. Plus if it doesn't have enough time to catch the ammonia in fast flow the next molecules will be along pretty fast anyway

Too much flow in tank is well common sense so no need to mention.

Alot of what he says in Vid I agree with as to running costs etc

The DIY King has some great vids advise, but some of his testing/comparisons are not the best. He was comparing a Kessil 360 with one of his DIY lights and was swapping the lights over every couple of weeks on the two different tanks, not really scientific or a decent comparison IMO. Dont get me wrong the DIY light works OFC.



kadoxu said:


> It's only my opinion...



Which I respect M8 , Just having a friendly debate.



PBM3000 said:


> I tried that. Every time the filter was switched off, all the detritus just fell off and re-polluted the tank



just cover the prefilter with fine net before switching of to catch the detritus it does the trick here.



PBM3000 said:


> Who runs two canisters on their tank?



One main filter and two DIY CO2 reactor canisters with Bio Balls.- testing them ATM


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## PBM3000 (9 Aug 2017)

> just cover the prefilter with fine net before switching of to catch the detritus it does the trick here.


Intake's in an awkward position as it is - I'd end up wrecking stuff! 

Don't get me wrong: there's sponge and biomedia in the 306, together with oodles of floss.


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## kadoxu (9 Aug 2017)

Zeus. said:


> Which I respect M8 , Just having a friendly debate.


Of course it is!  I just wanted to make it clear that I had no scientific evidence to back my opinion up. The video was where I heard about it, so I though it was a better explanation than the one I would write.



Zeus. said:


> The DIY King has some great vids advise, but some of his testing/comparisons are not the best. He was comparing a Kessil 360 with one of his DIY lights and was swapping the lights over every couple of weeks on the two different tanks, not really scientific or a decent comparison IMO. Dont get me wrong the DIY light works OFC.


Yeah... that one was probably the worst video he ever did (information wise), as in the following videos he ended up discarding his DIY lights for the Kessil.



PBM3000 said:


> Who runs two canisters on their tank?


I run a EHEIM Professionel 4+ in my Juwel 240, which is a goldfish only tank, but since the fish are still small it's enough for the next year, but the plan is to get another one.


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## dw1305 (9 Aug 2017)

Hi all, 





PBM3000 said:


> Every time the filter was switched off, all the detritus just fell off and re-polluted the tank.





Zeus. said:


> just cover the prefilter with fine net before switching of to catch the detritus it does the trick here.


What @Zeus. says and just syphon out any the net misses. 





PBM3000 said:


> together with oodles of floss.


I'm not a floss fan. If you have it in a canister filter, you need to be meticulous about replacing it every time you have any drop in flow. 





PBM3000 said:


> Who runs two canisters on their tank?


I have two filters on nearly all the tanks, (the second one is a powerhead, venturi and sponge) I don't have two canisters because I don't have any larger tanks than 60cm. 

If I have larger tanks again I will return to a trickle filter (or a HOB) and a canister filter. 

cheers Darrel


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## jon nash (9 Aug 2017)

PBM3000 said:


> Who runs two canisters on their tank?


a mate had 2 filters joined together worked fine


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## PBM3000 (10 Aug 2017)

Thanks for all the replies and opinion.

I guess what I'm saying is... "_could I get away with_ just the Eheim?"

I also really want to justify decommissioning my Vecton UV, too. 

*240l tank. 
Moderately planted. 
Current stock (with no plans to increase): *
I'm of the opinion that this is a light bioload, considering the plants and given only the platys are anywhere near the heavy end of the poop scale!
8x Cardinals
8x Ember Tetra
6x Misc Corys
12x Green Tiger Barbs
8x Misc Platys
3x SAEs
15x Amano Shrimp
9x Rummy Nose Tetra

Pic:


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## zozo (10 Aug 2017)

PBM3000 said:


> I also really want to justify decommissioning my Vecton UV, too.



The pros and cons? Especialy the cons are merely based upon theories, there is no real concrete evidence for the negative effects in practice. The pro's as for sterilization purpose are proven facts.. Tho, if the bulb aint strong enough and the organisms contact time with the radiation isn't long enough it wont do much (positive) harm with it. The later is applicable to most of the little commercial hobby use UV sterilizers out there in the LFS, the majority is constructed much to small with to little power to proof they realy effective.

So the biggest con, it's theory, injects you with an idea and the market jumps on it to provide you with an affordable home version, more to get your money than anything else. It consummes power and hangs around in the "if it doesn't benefit, it doesn't hurt" make believe area.

Next to, practice proved that in a biologicaly and chemicaly healthy well maintained tank with regular water changes there aint much to find for an UV light to kill what the fish cannot fight off them selfs.

As said above, for water clearity, learn to deal with the cause instead of spending cash to patch a technicality and keep yourself desperately ignorant.


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## roadmaster (10 Aug 2017)

I suspect  with large fish like  video depicted,,(Many other large species) that large frequent water changes are a big part of maintaining water quality in addition to filtration even with large moving sand type filtration.
You might can build all manner of filtration ,but water changes would in my view be insurance against power failure.


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## PBM3000 (10 Aug 2017)

I guess I could switch it off for a month or so and see what (if anything) happens...


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## Zeus. (10 Aug 2017)

But taking it to another level gilhams in thialand has some of the largest Freashwater fish in the world Arapaimia to 560lB for you to catch and return OFC no water changes going on there unless it rains OFC. They do top it up from the local river from time to time. They do run aerators all day and night OFC.


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## zozo (10 Aug 2017)

PBM3000 said:


> I guess I could switch it off for a month or so and see what (if anything) happens...


The predicability you wont notice a difference is highest.. 

To be honnest i've tried one, just because against beter judgement i still was curious.. Accidently constructed my sumps piping idealy to fit a UV tube light 24mm x 300mm in the excisting sumps 32mm x 30mm tubing. So i bought one, 3 x over powered according its specs vs the tank volume, to be sure at least theoriticaly it is strong enough. Installed it in the sumps tubing where it's constantly submersed in the flow. So the water has a 3mm gap over a lenght of 30cm in 360° over the UV tube to pass before it ends up in the sump. With approximately 2 to 3 times turn over. The tank ran over a year without it.. Now it's running over 6 months with a UV light installed. I do not notice anything beneficial, nor anything negative regarding micro fert deficiencies.. Can't tell what it does or if it does anything, but consume power. Only thing i have is my believe, which was always sceptic to begin with. 

As said, i made it because accidentily created the ideal situation. Else i wouldn't even got the idea i guess.. Any extra experience is one more to add, it wasn't that expensive and worth a try from a experience (also constructional) perspective and maybe proof myself wrong. Tho yet still waiting for that wonder or deficiency to happen..


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