# Reverse-Flow Undergravel Filter?



## the_skdster (Aug 15, 2006)

I was thinking of this for my next tank that will have gravel instead of sand.
If I have a reverse-flow UG filter, the dirt and grime will be forced free-floating and get sucked into my filtrations sytem, yes?
Of course I'll get a good prefilter on all my Intakes.
Good Idea?


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## ...Jay... (Nov 2, 2006)

I'm trying to picture this set up. And Im thinking the bubbles would not deperse throught the tank, they would probably just come up in the area where you have the air going under the plate. And if you did manage to rig it up where it came up everywhere it would probably stress your fish out.

Hard to say for sure, but my guess is, its not gonna be a good idea.


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## assclown (Dec 12, 2005)

ive seen plumbing in which water will flow thru a powerhead and pvc piping will come
up at the bottom of the tank at both ends, but yours, im having a difficult time picturing it


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## rocker (Aug 12, 2005)

the_skdster said:


> *the dirt and grime will be forced free-floating*


you think thats a good idea?


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## ttldnial (May 14, 2003)

I often thought of doing this with my main tank, but didnt.

One thing I do know is if it worked then not only would the filter be picking it up, BUT you would probably want to rinse the prefilters alot.. (try and not let all the collected debris escape).


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## Doktordet (Sep 22, 2006)

Here's how I see it. If you decide to use UG, there are more benefits using it in the "usual" way rather than attempting to reverse-flow. If you reverse-flow, your anticipated results would depend, of course, on many factors including gravel particle size, power head water flow, and gravel depth.IMO.


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## the_skdster (Aug 15, 2006)

rocker said:


> Here's how I see it. If you decide to use UG, there are more benefits using it in the "usual" way rather than attempting to reverse-flow. If you reverse-flow, your anticipated results would depend, of course, on many factors including gravel particle size, power head water flow, and gravel depth.IMO.


Guess I'll give it albeit more thought before I go through with it.
I got a few more months to go b4 I get another setup anyways.


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## BlackSunshine (Mar 28, 2006)

Standard UGFs are not good for a reverse flow filter. Water is likley to find the easiest route and not flow thru the entirety of the system. you would want an actuall reverse flow undergravel system. the only company I know of that makes one is Azoo. I actually have one that I have never gotten around to setting up. Its basically a system of tubes with small slits cut into it.


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## the_skdster (Aug 15, 2006)

BlackSunshine said:


> Standard UGFs are not good for a reverse flow filter. Water is likley to find the easiest route and not flow thru the entirety of the system. you would want an actuall reverse flow undergravel system. the only company I know of that makes one is Azoo. I actually have one that I have never gotten around to setting up. Its basically a system of tubes with small slits cut into it.


System of tubes?
Seems like I'll be able to make one out of a dozen or so small PVC tubing and attaching them side by side somehow.
*continues to ponder*

EDIT: any link to how it looks like?


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## Coldfire (Aug 20, 2003)

[/quote]
Why not? Better the grime go into the filtration system/prefilters *rather than make my Nitrates Skyrocket*.
I replace my DIY prefilters everyday by the way. They are chocolate brown everytime.
Between my AC110, EMP400 and Eheim 2217, my water clears up within minutes after a sand vac. Done twice a week.
[/quote]

An UG filter will cause your NO3 to be higher anyway. UG filters are NO3 traps. It really does not matter with you have a regular flow or reverse flow. You will still end up with an excess detritus build up under the filter plate.


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## the_skdster (Aug 15, 2006)

Why not? Better the grime go into the filtration system/prefilters *rather than make my Nitrates Skyrocket*.
I replace my DIY prefilters everyday by the way. They are chocolate brown everytime.
Between my AC110, EMP400 and Eheim 2217, my water clears up within minutes after a sand vac. Done twice a week.
[/quote]

An UG filter will cause your NO3 to be higher anyway. UG filters are NO3 traps. It really does not matter with you have a regular flow or reverse flow. You will still end up with an excess detritus build up under the filter plate.
[/quote]
After careful consideration, I see that you are correct.
*now ponders how to make this still work somehow...*


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## BlackSunshine (Mar 28, 2006)

I wonder how you guys figure NO3 gets trapped under the filter when it has constant water flow going thru it that forces it up thru the substrate and out into the tank. Where is it getting trapped?


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## Ægir (Jan 21, 2006)

really it doesnt matter, sh*t will still build up underneath there... and then you are back to the same problem you have in the first place... cleaning underneath... your water quality will start to crud up after a month with a good bio load and you will be doing massive water changes, untill you can get it outa there, or clean underneath and re-cycle your tank... or store all the water thats already cycled



BlackSunshine said:


> I wonder how you guys figure NO3 gets trapped under the filter when it has constant water flow going thru it that forces it up thru the substrate and out into the tank. Where is it getting trapped?


small chunks clog slots or holes... it backs up from there... into a sh*t dam with crap water down stream


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## BlackSunshine (Mar 28, 2006)

Skunkbudfour20 said:


> I wonder how you guys figure NO3 gets trapped under the filter when it has constant water flow going thru it that forces it up thru the substrate and out into the tank. Where is it getting trapped?


small chunks clog slots or holes... it backs up from there... into a sh*t dam with crap water down stream
[/quote]

But this is a reverse flow. the water going into it is regular tank water. If set up properly there should be a prefilter on it. and unless every slot was clogged there really is no where for anything to get trapped. 
I will post up a pic of my R flow UG later. If I can remember where I put it. (or rather where wifey cleaned it to.)


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## Ægir (Jan 21, 2006)

BlackSunshine said:


> I wonder how you guys figure NO3 gets trapped under the filter when it has constant water flow going thru it that forces it up thru the substrate and out into the tank. Where is it getting trapped?


small chunks clog slots or holes... it backs up from there... into a sh*t dam with crap water down stream
[/quote]

But this is a reverse flow. the water going into it is regular tank water. If set up properly there should be a prefilter on it. and unless every slot was clogged there really is no where for anything to get trapped. 
I will post up a pic of my R flow UG later. If I can remember where I put it. (or rather where wifey cleaned it to.)
[/quote]
well ill get in paint and make one.... its your birthday and get high if you want to....







\










ok... blue is gravel... this would be regular flow... now thats how it was setup in my tank which means all large solids are broken down to smaller chunks, travel through gravel and then become trapped underneath... if you flip those arrows and are sucking from the top of the tank, pushing it under the gravel, and ug-filter its going to build up faster, then become trapped in the gravel, and eventually be forced free floating, sucked in the top and trapped under the gravel..... wither way for a forcing poop to be in the water column, or letting it settle and pollute the water column....same fuckin waste of space, and time... DITCH IT unless you keep 10gal guppy tanks.... thats all its made to handle is a minute poop load

how about this, set it up, then in one month with a good sized fish in the tank...i want you to look under the filter, and we will see...but i dont wanna say i told you so


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## the_skdster (Aug 15, 2006)

Skunkbudfour20 said:


> I wonder how you guys figure NO3 gets trapped under the filter when it has constant water flow going thru it that forces it up thru the substrate and out into the tank. Where is it getting trapped?


small chunks clog slots or holes... it backs up from there... into a sh*t dam with crap water down stream
[/quote]

But this is a reverse flow. the water going into it is regular tank water. If set up properly there should be a prefilter on it. and unless every slot was clogged there really is no where for anything to get trapped. 
I will post up a pic of my R flow UG later. If I can remember where I put it. (or rather where wifey cleaned it to.)
[/quote]
well ill get in paint and make one.... its your birthday and get high if you want to....







\










ok... blue is gravel... this would be regular flow... now thats how it was setup in my tank which means all large solids are broken down to smaller chunks, travel through gravel and then become trapped underneath... if you flip those arrows and are sucking from the top of the tank, pushing it under the gravel, and ug-filter its going to build up faster, then become trapped in the gravel, *and eventually be forced free floating, sucked in the top and trapped under the gravel*..... wither way for a forcing poop to be in the water column, or letting it settle and pollute the water column....same fuckin waste of space, and time... DITCH IT unless you keep 10gal guppy tanks.... thats all its made to handle is a minute poop load

how about this, set it up, then in one month with a good sized fish in the tank...i want you to look under the filter, and we will see...but i dont wanna say i told you so
[/quote]
Umm, thats wht PRE-FILTERs are for.


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## Ægir (Jan 21, 2006)

i read that... but its just one more thing to clean... no you have to still clean under the UG filter, clean prefilters, and worry about water changes and the countless other things.... i thought you were trying to make things easier on yourself but... do it, and see how much easier it turns out to be, especially keeping constant, perfect water conditions after a month or so








instead of gravel vac, add water, check filter operation... which is my routine weekly, seems pretty easy to me but?


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## BlackSunshine (Mar 28, 2006)

again we are talking about a regular UG filter used in reverse. I'm speaking of a designed reverse flow ug filter. There is nothing to get trapped under because they are tubes not plates. 
I got a new camera last night so I will take pics tonight.


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## Ægir (Jan 21, 2006)

i am talking about a "reverse flow undergravel filter" too... i have tried it, both ways... obviously they would design them to work that way out of the box if it was any different, or better...

K.I.S.S : keep it simple stupid


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## the_skdster (Aug 15, 2006)

BlackSunshine said:


> again we are talking about a regular UG filter used in reverse. I'm speaking of a designed reverse flow ug filter. There is nothing to get trapped under because they are tubes not plates.
> I got a new camera last night so I will take pics tonight.


Looking forward to that.


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## Doktordet (Sep 22, 2006)

Correct me if I'm wrong. Arent bacteria residing underneath the plates and in the gravel supposed to "break down" the poop and all the detritus? So it really doesnt matter if waste accumulates under the plates, because thats what it's supposed to do in order to keep the nitrifying bacteria alive in the gravel and under the plates. ???


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## BlackSunshine (Mar 28, 2006)

Doktordet said:


> i am talking about a "reverse flow undergravel filter" too... i have tried it, both ways... obviously they would design them to work that way out of the box if it was any different, or better...
> 
> K.I.S.S : keep it simple stupid


Well the whole concept of reverse flow UG's is not a mainstream idea. and there really aren't any companies making true reverse flow UG's just adapters to in essence make a normal one work like a reverse flow. optimally you could hook up one of these specially designed ones up to the return of a cannister filter and have a really good filtration system.... Damn I wish I thought of that when I redid my 75gal.









Heres a crappy example of the way my system works.








Along the lenght there are small slits in the piping that flow the water back out into the tank. 
so there is nowhere for anything to get trapped. unless you set it up crappy and dont have any kind of prefiltration. just think of how much more surface area is in your substrate that can be used for bio filtration that goes untapped. And using this system will also get ferts to the roots of plants better. 
this of course isn't going to be the only filtration you will want for a large predator tank. and not going to do much for you if you want surface agatation. but IMO is a great filtration for a planted tank. less hardware in the tank and creates no surface agatation to offgass CO2.


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## the_skdster (Aug 15, 2006)

BlackSunshine said:


> Correct me if I'm wrong. Arent bacteria residing underneath the plates and in the gravel supposed to "break down" the poop and all the detritus? So it really doesnt matter if waste accumulates under the plates, because thats what it's supposed to do in order to keep the nitrifying bacteria alive in the gravel and under the plates. ???


the bacteira is actually in the substrate itself when a ug filter is used. the movement of water thru the substrate is how the bio load gets broken down. UGs are not ment as a mechanical filtration device. altho in normal flow they do help break down some of the larger peices of poop. In reverse mode this is not the case. because initally you don't want those large chunks going thru the powerhead. and more so you don't want to push those big chunks thru the filter as it will quickly clog either type of system.
[/quote]
^^^I'm really starting to like thisa guy.








He's so informative.


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## CLUSTER ONE (Aug 2, 2006)

i dont think it would be powerful enough without being too powerful
you should just try hooking a filter to it then it sucks up the dirt that fell throught the gravel

the bacteria is good to break it downt but to much screws up water conditions


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## Doktordet (Sep 22, 2006)

BlackSunshine said:


> Correct me if I'm wrong. Arent bacteria residing underneath the plates and in the gravel supposed to "break down" the poop and all the detritus? So it really doesnt matter if waste accumulates under the plates, because thats what it's supposed to do in order to keep the nitrifying bacteria alive in the gravel and under the plates. ???


the bacteira is actually in the substrate itself when a ug filter is used. the movement of water thru the substrate is how the bio load gets broken down. UGs are not ment as a mechanical filtration device. altho in normal flow they do help break down some of the larger peices of poop. In reverse mode this is not the case. because initally you don't want those large chunks going thru the powerhead. and more so you don't want to push those big chunks thru the filter as it will quickly clog either type of system.
[/quote]

Ok. Thanks. got those pics? curious to see what it looks like.


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## the_skdster (Aug 15, 2006)

shark_boy said:


> i dont think it would be powerful enough without being too powerful
> you should just try hooking a filter to it then it sucks up the dirt that fell throught the gravel
> 
> the bacteria is good to break it downt but to much screws up water conditions


An AC802 would do a 75gallon plenty meguess.
If not, and AC901, does 950gph.


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