undergravel filters: pros and cons

revfred

Superstar Fish
Jun 21, 2003
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St. Paul, MN
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#4
IF you have to have them . . . run them with a powerhead that has a reverse-flow feature to make cleaning easier. I've had them long ago and can't imagine what the "pro" would be when there is excellent medias for HOB and cannisters available. And definitely bad news if you want to grow live plants.
 

Triple88a

Small Fish
Jul 9, 2006
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#6
I'm confused a bit.. everywhere i read people say undergravel system is a no no with live plants...

I set up my 45 gal tank in a wird way...for the past 2-3 months i was using 2 seperate plates for undergravel filter thingy - the left plate had a powerhead which I kept off most of the time while my right plate was connected to the filter which i kept on all the time. The plants over the left plate are about 3-4" in lenght with few leaves and the the plants on the right are about 5-6" with a lot more leaves.

I'm currently looking for a more "correct" way to set it up but anyhow looks like the undergravel system totally boosted my plants growth compared to where the undergravel system wasnt on.

ps: I have 2 filters one was just connected to suck from the center of the tank while the other one sucked from the underground filter.
 

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TLH

Large Fish
Jun 27, 2005
703
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Northants;England
#7
Rooted plants generally don't like UGF's.I had a Amazon Sword that did suprisingly well though with mine no matter what abuse I threw at it.What I mean is I didn't fertilize and I would pull off the bigger leaves as it was in a smallish tank.Floating plants and plants that don't rely on roots are fine.

Best thing about UGF's is they are ideal for fry as the suck action is spread all over the gravel instead of being in one place.Next best thing IMHO is that the bacterial area is the greatest you can get,even bigger than any external filter,so bacterial action is quicker and greater.

With a powerhead on mine I don't think cleaning is all that bad.The gravel is fairly course (fine gravel would drop through my plates) and traps the mulm well and all I have to do is vacuum once a month.
 

Lotus

Ultimate Fish
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Aug 26, 2003
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#8
To be honest, three months isn't really enough time to determine if the tank is really working well. In a year, after you've done your UGF breakdown and rebuild, you may think differently.

I wouldn't say that even 6" of growth in 3 months is exceptional, some of my plants grow that much in a week, but it does depend on many factors.
 

Sep 11, 2005
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Philadelphia
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#10
In my years of gathering info from forums, websites, other aquarists' experiences etc, I have come to the conclusion that this whole business about UGFs being bad for planted tanks is pure crap.*

I put an asterisk here because I am not stating this from personal experience or scientific experiments. But I know of many situations where aquarists have maintained wonderfully planted aquariums for many years with UGFs, and yes, they were done so with several heavy root plants.

Some people have argued that the UGF actually helps these plants because it brings nutrients and circulation of fresh water to the roots.

That out of the way my opinion of UGFs are as follows:

Pros - massive place for bacteria colonization, absolutely no cost for media replacements, can be completely silent, safe for fry tanks and slow swimmers like bettas.

Cons - absolutely disgustingly dirty. keeps all of the dirt, mulm and filth in the tank and thus must be constantly maintained by turning the gravel bed and heavy vacuuming; which in the end still doesn't result in the removal of all the accumulated waste if the tank has a large number of, or very messy inhabitants. Doesn't allow for any sort of customization (can't add any specific chemical filtration like peat, carbon or phos-zorb) and just generally not worth it in the long run.

Verdict - if you want to save money on filter media, it's your best choice. But other than that, completely unnecessary. There are other and better choices for almost every purpose imaginable.
 

fish_chic

Large Fish
Oct 30, 2006
386
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florida
#11
i have a UGF in my tank, i have been wondering if i sould get a canister or a powerhead to go along with it. the guy that i got the tank said i souldn't bc he really believes in the these filters (said it works like a septic tank) does any one else think i shoud get another filter to go along with the UGF? i can still see very small specs of something floating in the water, is that okay?