Undergravel filter

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martiniduck

Aquarium Advice Activist
Joined
Apr 1, 2009
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133
Location
St. Charles, IL
I have been reading much about undergravel filters. About 70% of what I have read has said that they are more of a problem than a benefit for the tank. I was always under the impression that the undergravel was like a huge built in filter. I am thinking of removing it from my tank. Is their anything I should be careful about before or after removing it from the tank? I am wondering has there ever been any scientific tests done to see if they are really not a good source of filtering? Did someone use the scientific method to test it? Using multiple tanks and a control tank or is this just hearsay? Just wondering?
 
I have gone full circle on support for under gravel filters. I used them exclusively years ago. The only problem was that the gravel got clogged over time with all the decaying matter; especially from driftwood.
I then switched to HOBs; now canisters.

Recently I ran a tank with a relatively heavy bio-load of fish with only a power head circulating water over the gravel. Surprisingly it kept nitrites & ammonia at zero.

I am now seriously thinking of going back to an under gravel filter for my next tank setup. None of my canisters/HOB combination can compare to the total surface area from the 60 to 100lbs of gravel I have in my various tanks. The thing I will do different is I will use a reverse flow and add a filter sponge on the input tube. I also have eliminated driftwood in my tanks as that is the number one source of solid waste (brown crud).
 
I run an RUGF on my 52g, hobs on my 40 and wet/dry on my 45

my 52g also has a canister but when the power goes all the canisters are known to spit toxic matter back into the tank, its just physics.

my 52 hasnt had a gravel vac in over 6 months, underside of plate is still clear, some mulm but I can see the plate just fine still.

UGF's create the utmost surface area for bacteria to thrive on, with the amount of gravel on top, nothing compares. There is a guy known as paul B who has been running a RUGF for 30 years with no problems what so ever.

VFC, marineland makes one called the 660R, its set in reverse flow with filter attached, it runs about 45 bucks, I got two of em, I love them.
 
i had one set up in a turtle tank i had. the filter was for a 10gal tank, i put it on one end of a long 20gal and had a power head pulling water thru the gravel and dumping the water on a rock then it would run down and return to the pool for the turtle im not sure if that would be a normal flow or reverse flow but it worked quite well for that app.
 
I have a UGF on my 75 gallon, and have had them on pretty much every tank I have had over the last 30 years. I always use power heads, and keep the gravel depth down to about 1 inch. I also always use them in addition to some other sort of filtration, mostly HOBs. I use a Python to clean alternating halfs, every two or three weeks, when I do a 50% water change. I always make a point of pushing the Python down firmly to the UGF plate, and holding it there while waiting for the cloud of debris to get sucked clear before lifting straight up and moving over to the next spot.

As a result (I believe), I do not build up much crud under the plates, if any. Last fall, I removed the fish for a few hours and pulled out all the gravel, and the plates. So I had a good look at what had built up over the previous 4 years...not much. (I tie my plants to the UGF plates with fishing line so that they do not float away every time I clean the gravel, and I was in the mood to move the plants to new spots in the tank. Pulling the plates out of the tank makes re-tyeing (sp?) everything MUCH easier!)

I think UGFs can be a good additional form of filtration IF they are used with strong-enough power heads, are cleaned well, and do not have too much gravel. FYI, I have fancy goldfish, mostly plastic plants (sometimes I add floating real plants, but they usually just get eaten), and no driftwood.

If you decide to remove your plates, be sure to move your fish out of the tank first. There has been some concern that the removal of the plates might release dangerous gasses of some sort into the water. These gasses will dissipate, but your fish should not be exposed to them in the meantime... I am not sure if this is true, but why risk it?
 
I have been reading much about undergravel filters. About 70% of what I have read has said that they are more of a problem than a benefit for the tank. I was always under the impression that the undergravel was like a huge built in filter. I am thinking of removing it from my tank. Is their anything I should be careful about before or after removing it from the tank? I am wondering has there ever been any scientific tests done to see if they are really not a good source of filtering? Did someone use the scientific method to test it? Using multiple tanks and a control tank or is this just hearsay? Just wondering?

I think the main complaint is that they are a pain to maintain and almost impossible to get at once they are in place. But if it is working for you, why change it now?

If you really do want to change, think what alternative filtration you want. I would say you need to be running the other filter alongside your under gravel for at least a month before removing the under gravel filter.
 
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