# Upping your current canister filters output.



## chris1004 (13 Mar 2010)

Hi,

Been thinking....OUCH!!!!!  

The following is purely hyperthetical.


If I were to remove the impeller and leave my current filter unplugged and instead install a high LPH rated pump inline in the return hose to the tank would it have the desired effect of increasing the flow through the filter and would it be safe to do? 

Just a thought.

Regards, Chris.


----------



## Dolly Sprint 16v (13 Mar 2010)

Chris 

Theorically yes - but actually "NO" the flow rate is controlled by the quantity of media within the canister unit, to inprove the flow from the canister remove some of the media - but we dont want to do that as filtration would not be as good.

Regards
Paul.


----------



## Ed Seeley (13 Mar 2010)

The flow rate through any filter is a combination of the resistance (usually referred to as the head) and the performance of the pump.  Some pumps work well against higher heads (but tend to use more electricity) so would do what you wanted.  However it would be much better (and much more energy efficient) to swap it for a larger filter, or add a circulation pump in the tank.

The filter media is only part of the frictional (resistance) head generated by the filter.  Depending on what media you use and what filter you have the flow rate can be totally independent of the quantity of media.  A small amount of fine filter media (with little void space) will reduce flow far more than a huge amount of open void media - quantity is irrelevant.  On a lot of canister filters the pipework and fittings used can create much more head than well chosen media - especially if using poorly designed glass inlets.

By the way you can also have an open void filter media (that allows a large amount of water to flow past with low head) with huge surface area allowing excellent biological filtration.  I'm referring to the hoop shaped sintered glass filter media and a canister full of that will lose almost no flow due to the media unless it's so dirty the whole thing blocks.


----------



## chris1004 (13 Mar 2010)

Flyfisherman said:
			
		

> Chris
> 
> Theorically yes - but actually "NO" the flow rate is controlled by the quantity of media within the canister unit, to inprove the flow from the canister remove some of the media - but we dont want to do that as filtration would not be as good.
> 
> ...



Hi Paul,

I don't agree with you there mate as Ed pointed out in the next post from yours its all about the frictional head, of which the media is just a part of, and the pump. Kind of like a power - weight ratio. By reducing the weight (i.e. the media in this analogy) it does increase the flow but as you quite rightly point out it isn't all that desirable to have less media most of the time. but by increasing the power (i.e. the pumps LPH) it will increase the flow without suffering a reduction in filtr media. 



			
				Ed seeley said:
			
		

> The flow rate through any filter is a combination of the resistance (usually referred to as the head) and the performance of the pump. Some pumps work well against higher heads (but tend to use more electricity) so would do what you wanted. However it would be much better (and much more energy efficient) to swap it for a larger filter, or add a circulation pump in the tank.



As I said its just hyperthetical I'm not considering doing it,* YET*, but I couldn't actually fit any larger filters under my tank as the cabinet wouldn't have sufficient head room for starters. But running cost aside for a minute what your saying Ed is that yes it could be possible which is exactly what i was thinking originally.....

Somthing like this.

http://www.zooplus.co.uk/froogle_uk/-1287/shop/fish/filters_pumps/air_pumps/air_pumps/114877

Which is available upto 5000 LPH and there are possibly other pumps which could even have higher ratings as a possible option....So my EX1200's which lose about 50% of there stated flow rate when full of media could actually be modified with the addition of a dedicated inline pump to have an actual flow far exceeding that of the original manufacturers specification???    

Regards, Chris.


----------



## Ed Seeley (13 Mar 2010)

It's not the output per se that governs how successful this will be but the head the pump can work against.  Some pumps move huge volumes of water at low head (low resistance) but fail miserably when the head increases.  Most aquarium pumps seem to be in this category.

When you start looking at pond pumps they fall into two main categories: High wattage pumps that can cope with high heads and low wattage pumps that are useless against high heads but great at moving large amounts of water at low heads.

For an external filter you also have the issue that the narrow tubing will severely limit the flow rate through the filter.  I would look at adding a Koralia to your tank to increase water flow (or an external pump on a seperate loop if you really can't stand the extra hardware in the tank) as you will then up your tank's flow rate in the most effective way IMHO.


----------



## chris1004 (13 Mar 2010)

Hi Ed,

I'm really just batting an idea about here. I have two Koralia's and ample filtration so I'm not looking for a solution to a problem just wondered what people think of somthing that occurred to me, thats all, thankyou for your input though.

The pumps that I linked to can handle a head height of 3 metres which is almost twice that quoted for my canister filter and on the face of it they appear that they will more than double the flow (the 5000LPH one).

If it were to work I'm sure some people might find it a cheaper option than buying new canister filters and as you pointed out it could possibly get those damn ugly Koralias out of the picture.....

As for electricity costs I hear what your saying and understand the maths behind it all completly. Lets assume that the pump is the 5000LPH one in the link provided which is rated at 78W and because I now have no need for the canister filter pump at 25W the difference that I'll have to pay for is 78-25=53W. The unit of measure that we're charged for our electricity is KWH which is 1000W on for 1 hour = 1 unit. Therefore 1000/53 = 18.87hrs for 1 unit of electricity. 365 days x 24hours divided by 18.87 = 464.23 units anually. The average cost at the minute in the UK is about 12.5p per KWH. Therefore the running cost would be 464.23 units x 12.5/100= Â£58 a year or 16 pence per day  extra. About 15-20% of this would be further offset if I could take the two Koralias out of the tank.      

Regards, Chris.


----------



## Ed Seeley (13 Mar 2010)

Sorry Chris, you're misunderstanding me slightly, I obviously didn't explain myself very well!  

A head of 3m isn't that high really (and, at maximum head, flow will usually be almost nothing) - I'm talking about pumps such as these (http://www.coastal-koi.com/shopping.php?class_id=48) that can handle heads of up to 20m!  (Even the low head/high flow pond have heads of 3-5m plus.)

The Ehiem pump you linked to are great pumps by all accounts but still have open impellors and do not force the water down the pipe like the high wattage/high head pond pumps that use closed impellors.  They function like the impellor of a standard canister filter or low wattage pond pump.

Basically I'm saying, yes it is theoretically possible to shove more water through a filter than it is designed to using a higher capacity pump but practically it is a very inefficient way of doing things as the filter won't be designed to allow that increased volume at a higher velocity through effectively.  A separate loop would be much, much better.  Also at some point you will reach a limit where you physically cannot get more water through the pipework as it has reached its maximum capacity and then all the power in the world won't help (but that'd take a huge pump running at huge pressure!).


----------



## dw1305 (15 Mar 2010)

Hi all, 





> By the way you can also have an open void filter media (that allows a large amount of water to flow past with low head) with huge surface area allowing excellent biological filtration. I'm referring to the hoop shaped sintered glass filter media and a canister full of that will lose almost no flow due to the media unless it's so dirty the whole thing blocks.


 this is a lot of the answer, as it is usually the media that slows the flow through the filter. I've done some work on waste water with a huge BOD, and the actual volume of biological media you need is much smaller than you might imagine. A combination of open void media, low head/high volume pump and (ideally straight) large diameter piping will give the smallest reduction in flow speed & volume because there is little constriction to the water flow, and the low head means that you don't waste a lot of energy pumping the water against gravity. Sumps/most canister filters use gravity to feed the water into the sump and a return pump back to the tank, but one of the the most efficient method is an over-tank trickle filter, with the water pumped up to the top of the trickle "tower" and returning under gravity. Have a look at the trickle filters for Koi ponds that use "alfagrog" or similar as a media. 

cheers Darrel


----------



## Ed Seeley (15 Mar 2010)

Actually Darrel you're really only half right there about koi filters (all I seem to be doing on this thread is disagreeing with people - sorry and no offense meant to anyone).

The trick with a good koi filter is to feed the dirty water from the pond under gravity rather than pumping it to the filter.  The problem with feeding water via a pump is that the waste gets mashed which makes it much harders to mechanically remove whereas gravity feed allows the waste to pass to the filter without getting broken up.  The most efficient mechanical filters (at the moment) compromise a sieve that removes the waste from the water column, preventing it breaking down and realeasing more ammonia.

Once you've got the waste out you can then filter it biologically.  The two most efficient ways of doing that is either with a moving biological bed (small, slightly bouyant plastic media made to move with air bubbled through it which also adds vital oxygen) or with an open shower filter which is like the trickle tower you talked about.

Ironically (as we started this talking about canister filters) the one filter often seen in koi mags that I would never tough with a bargepole on a koi pond is a bead filter which is like a giant sealed canister filter full of beads.  This is because it traps the waste in the biological media reducing its effectiveness and also has no air added to the media to supply lots of oxygen to the bacteria.  It would however possibly be a good choice on a giant planted tank as it wouldn 't gas off lots of CO2.

BTW I run both a gravity fed moving bed filter on one pond and a shower on another.  Which do I think is the best?  Shower by miles, but with gravity fed mechanical filtration first.  And I've got a ceramic media like giant sintered glass media in it too - awesome filter.  A lot of people think gravity filters are more efficient though as you can run and even return the water just by using air uplifts - much cheaper than using a water pump (not too practical for an under tank filter though!)


----------



## dw1305 (16 Mar 2010)

Hi all, 


> The trick with a good koi filter is to feed the dirty water from the pond under gravity rather than pumping it to the filter. The problem with feeding water via a pump is that the waste gets mashed which makes it much harder to mechanically remove whereas gravity feed allows the waste to pass to the filter without getting broken up. The most efficient mechanical filters (at the moment) compromise a sieve that removes the waste from the water column,  preventing it breaking down and releasing more ammonia.


 With apologies, I don't keep Koi, but that would be a very efficient method of removing the solids before pumping the liquid fraction through the  biological filter. In the 2 cases I was thinking of the solids had already been removed by a sponge pre-filter (the trickle filters I used in the lab), and by sedimentation in  the "rotating arm/clinker bed" style sewage treatment works. 





> .....gravity fed moving bed filter on one pond and a shower on another. Which do I think is the best? Shower by miles, but with gravity fed mechanical filtration first....


 For a high waste situation (large BOD) I'd always go for removal of solids first and then a trickle (shower) filter, mainly due to it's high gas exchange capacity (although this will out-gas your CO2). 

cheers Darrel


----------



## Stickleback (16 Mar 2010)

I do this... It works.

(Edit)

Sorry that wasn't very specific, was in a hurry. I have separate canisters for Mech and Bio. The Mech powered by a external pump, with the bio being a normally running Eheim on a loop off the main loop. Think like the handle on a t cup. Does that make sense, if not I will post a diagram. I did this for the same reason as you state, not enough room in cabinet for a FX5 or similar. The advantage of this is that you can place the CO2 after the cannister but before the pump. Then the pump diffuses the co2 even further.

So the powerhead is only powering the Mechanical filter which is a unpowered pond cannister filter. The powerhead turbo charges this, clearing floating debris from the tank much quicker than my previous setup. I spent a year battling algae with different smaller filter setups and this config is the one that eventually worked.

Give it a go, see what happens.

R


----------



## Jonatk (16 Apr 2019)

I have a problem in my 275G tank with a lot of suspended particles. My current thinking is that I dont have enough pull from my external filter, because if I did it would all get trapped in the pre filter, which contains 3 grades of sponge, filter floss and a 100 micron fabric. Something that was briefly touched on in this thread was the diameter of hose. On my inlet its 1/2" and on the outlet its 3/4", then just before the spray bar it goes into 1/2". So would changing the diameter of the hoses increase intlet power / outlet power. And if so which diameter for which inlet?


----------



## Zeus. (16 Apr 2019)

Jonatk said:


> My current thinking is that I dont have enough pull from my external filter, because if I did it would all get trapped in the pre filter, which contains 3 grades of sponge, filter floss and a 100 micron fabric


With all that micro/fine filters your filters output will be well reduced as the fine filters will be clogging your flow. I dumped all my fine filter media and just have course and medium in and the tank is fine for suspended particles.


----------



## Jonatk (17 Apr 2019)

Ive only just added the floss and 100 micron fabric. Although If that hasn't worked within a few days I may try that. Thanks. 
I still want to try and increase the pull though, as thats the only thing I haven't been able to do. I can clearly see near the inlet that there are fine particles not being pulled in. And although yes there is alot of media in the pre filter at the moment, the suspended particles were in the tank before I started changing the media


----------



## Zeus. (17 Apr 2019)

When I turkey blast my carpet the tank can be very cloudy with loads of suspended particles 30 mins later most of it has gone, so if the parcles arent being removed in a few hour the filter isnt good enough or too much fine media.


----------

