# Trickle Filter



## Aqua sobriquet (7 May 2012)

Nothing new here,  I'd just like your thoughts on making a "cylinder" trickle filter rather than a traditional glass sump type.  It all depends on availability of a suitable container or ease of making/modifying one.
The container would be sealed like a conventional external cylinder filter except for a suitable vent for excess air. I expect it would be safer to fit a non return valve and run an airline into the aquarium from the vent just in case. Or maybe it could go into the ouput line of the pump. Sorry about the rough graphic ...






I'm thinking to feed it from an automatic overflow. I just thought putting it all in a sealed cylinder would be cleaner/quieter and neater. Any thoughts? Have I missed anything likely to cause a puddle all over my floor!?


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## foxfish (7 May 2012)

You can use any shape you like.
What is the air stone for & the float switch?
How will you pre filter the water?
You will need an auto top up valve if you dont have a large reservoir & even if you do have a large reservoir you are still so much better off with a auto top up!


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## Aqua sobriquet (7 May 2012)

The air stone ensures enough oxygen for the bacteria - these are normally used in the conventional trickle filters I've seen. The float switch turns off the pump if the water level drops too low preventing it running dry. Again, these are normally used on trickle filters. Filter wool at the top of the column is used as a pre-filter but a sponge can also be used in the auto overflow.


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## foxfish (7 May 2012)

I can not see any benefit from having an air stone in the sump water.
The only time I have seen the effective use of an air pump was during the popularity of low pressurised trickle towers in the early 90s
I built & sold a few but, the additional noise & hassle of sealing the unit was not worth the the payback it terms of efficiency.

I dont know the size of filter or tank you intend to use?

Trickle filters work extremely efficiently but there are some issues, the main complaint is usually based around noise, the other issue is the amount of evaporation caused by exposing the contents of the tank to air, very often several times an hour.

My own 200lt display tank uses four liters of bio balls or approx 2% of the tanks volume. I have found this to be about right for a heavily planted tank with a reasonable fish load.
I feed about 800lt every hour over the bioballs, if you try & feed 10 x tank volume you will very effectively de gas your tank & that means feeding back in large amounts of C02.
In my home set up the tank looses about 10-13 liters a week so ensure your sump is kept topped up on a daily basis -
 or as I say - install an auto top up in the sump!
If you decide to use an external sump pump then choose very carefully as many can be very noisy, using a submersible option inside the sump will be less noisy depending on the amount of water in the sump.
I have never installed aftermarket overflows much preferring a cutout in the top of the tanks glass & a DIY overflow.
You tube design is fine for the tower but it wont hold much of a reservoir.


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## Aqua sobriquet (7 May 2012)

As I understand it early trickle filters were open topped to enable ample oxygen supply. The noise of trickle filters put folks off though so the next generation had sealed tops (with a small breather hole) hence the addition of an air stone. I suppose sealing the top would also reduce evaporation, probably quite a good thing inside a cabinet with electrical plugs etc.
Have you got any pics of your overflow? I'd be keen to have a look.


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## foxfish (7 May 2012)

Evaporation comes from the overflow more than the tower.

Noise comes from different components - gurgling from the pipe that runs from the overflow to the tower is more difficult to silence than the actual trickling of water through the media, that is not so difficult to subdue.   

I am talking about smallish fresh water systems here, larger tanks & ponds  systems can be extremely intrusive & noisy,

On most of my tanks I use grundfos circulating pumps because of thier reliability & quiet running.

I prefer, if possible, to avoid internal stand pipes & drilled bottom tanks much preferring to run flexible pipe to the tower from a high level. 

Dont forget than 5mm of evaporation from the display might equate to 100mm in the sump!

I may be slightly behind the times when is comes to the latest fads  :?  but, I have built & installed dozens of both pond & tank trickle systems, many of the pond filters are still running after 20 years.


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## dw1305 (8 May 2012)

Hi all,
I've made a few of these. I used to situate them above the tank and I used the design from  "Enjoying Cichlids, 2nd Edition" Ed. Ad Konings, in the filtration section by Kjell Fohrman and originally designed by Lasse Forsberg (on pg 32.).
I can't find a picture on the WWW any-where, but I'll scan the book one later.

I made a couple of changes, I used a large diameter round section drain pipe for the filter body, filled with hydroleca and a plant pot for the drip plate. You just pick the water up with a pump, with a sponge on the intake, and make the outflow pipe x2 the diameter of the intake. Gravity does everything else for you, and vertical towers are very effective at stopping water channeling.

In terms of ease of use, and efficiency, these are great filters, but they are a bit noisy.

cheers Darrel


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## Aqua sobriquet (8 May 2012)

Thanks for that, look forward to seeing the scan.


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## dw1305 (11 May 2012)

Hi all,
Here is the scan of the trickle filter from "_Enjoying Cichlids_". I thought that a round body should offer advantages over a square one (in avoiding channelling), and it also allowed me to use a section of drainage pipe and a  slightly adapted plant pot as a trickle plate. 

I didn't have any bioballs, but I would have used hydroleca even if I had had them. 





cheers Darrel


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## Aqua sobriquet (11 May 2012)

Thanks for the scan. Good to see different approaches to the system.


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