Under gravel filters

[FreshwaterTropical]

Hats the purpose of an ugf? Is it beneficial enough to actually use one? Can you have live plants with a ugf?

 

[glassbird]

UGFs are one of those subjects where people have widely differing opinions...some people hate them with a passion, and others use them just fine. In my experience, and with all the reading I have done on various forums, there is one major thing that you MUST have to make a UGF work...apropriately sized powerheads. You can NOT run a UGF with "air power". Don't even try. I run a UGF in my 75 gallon with 2 PHs...each is rated at 295 gallons per hour. (2 powerheads because there are 2 UGF plates in a 75 gallon.)

Correctly sized gravel is the next issue. I have always used gravel that is 3/8 to 1/4 inch in diameter, and always had 2-3 inches of depth, max. Other sizes might work, but this is the only size and depth that I have dealt with personally so I am comfortable recomending this. Sand will NOT work.

Live plants will NOT work. The roots will clog the plate slits.

And few more thoughts...UGFs work best along with some other type of filter...a HOB or cannister. (Running a UGF alone would only work if you had VERY few fish). Also, get a gravel cleaner and use it regularly and well.

 

[Dale_I]

The purpose of a UG is to use the gravel bed as the bacterial filter. This use d to be the best way until bio filters and canisters came on the scene.

I use a dual 200 gal powerhead UG plate in my 55 gal, with a Fluval 304 for mechanical and extra bio filter.

 

[Fishguy2727]

UGFs are old-fashioned and end up causing more harm than good long term and create more work for you in the process.

Sand is a much better substrate anyways, making the UGF issue pointless. Sand is much more natural, cleaner, and looks better.

 

[BillD]

The local Big Al's has almost all of their tanks using air powered UGFs. The tanks are usually heavily stocked. They have been doing this since the store opened quite a few years ago.
I had this discussion the other night at our society meeting with a long time hobbyist who had in excess of 650 tanks at one point. He used UGFs for many years, grew plants, and bred a huge number of different species. As he put it if the fish were breeding they were happy. I don't have any in use right now, because most of my tanks are barebottomed, but the last one I had running went 12 years without a teardown. It isn't that difficult to remove the debris from below the plate. A siphon tube place to the bottom of the lift tube removed most of it quite easily. if using a prefiltered powerhead in reverse flow configuration, there would be no debris below the plates. Having fish that dig can mess up the system, but I have seen more than a few cichlid tanks that used UGFs over the years. There has been a lot of nonsense disseminated regarding UGFs over the years, but the reality is that they were a staple in the hobby for many years because they worked and they were inexpensive. The reality is that they work as well today as they did 50 years ago.
Today there are more methods of filtration to choose from, but none of them can reduce ammonia or nitrate to less than 0, same as the UGF.

 

[lilbenchy9192]

its all opinion people always say they cause more issuses then they solve, but my dad has always used under gravel filters, in big and small tanks and swears by them so its up to u i think

 

[Fishguy2727]

The problem is that if you neglect them at all they can get very bad very fast. With a neglected HOB or canister you can take it off the tank, drag it to the sink or bath tub, and clean it out and be right back to where you should be with no major harm to the tank. That is not the case with UGFs. If they are neglected at all the debris gets trapped where it can't be removed. You can't drag out the substrate to the sink without releasing all the debris into the tank. Siphoning through the uplift tubes only removes the debris immediately adjacent to the tube (a few inches), not the whole area under the plate. And no filter media is 100% effective, so even with prefiltered RUGF you still get debris under the plate that cannot be removed without tearing it apart.

Again, sand is a better option for a substrate anyways. IMO in about ten years people will look at gravel the same way people look at UGFs now, old school with a few old dogs holding on to it because it was the way to go when they started, they figured out how to make it work well enough, and are sticking with it.

If you have ever seen a tank after the UGF is removed (and releases all the crap) you will see why so many hate them so much. It literally looks like the city has been pumping sewage through your tank.

With all the forms of filtration out there that are lower maintenance and easier to compensate for when life happens and you miss maintenance that do not pose the risks, it simply isn't worth it. Even in a small tank you would need a good pump, which along with the the UGF plate will cost you about the same as a decent HOB. There is simply no need to or gain by going with and UGF.

I have worked in shops that use them in their sales tanks. The difference between that and your home tanks is the fact that at a store you have multiple people on staff full time to work for you. That extra amount of labor can make up (at least partially) for the extra work required by a UGF. If you are at home and bored and want something that takes a little more work every week, get an UGF.

 

[Morgie]

I just removed the UGF that my dad had in my "first tank" from the time I was about three (early 90s). It was so disgusting and didn't work very well and that was enough for me to never use them again.
They /CAN/ work, but it's so much easier to maintain a HOB or canister

 

[chagoi]

I used them about 30 years ago. There are better was to filter today.

 

[lilbenchy9192]

ive got to agree about the fact that they may not the most effective but then i often find as things are becoming to perfect, to clean, to labour saving, it kinda means u have no reason to play with the tank, personaly im allways fiddling because its what i enjoy

 

[BillD]

Siphoning through the uplift tubes only removes the debris immediately adjacent to the tube (a few inches), not the whole area under the plate.

This is untrue based on my personal observations, by viewing the tank from below while the siphon tube was at work. As far as low maintenance goes, the Hamburg mattenfilter has to be the king. They can go a year or longer with no maintenance.
Sand is not necessarily easier to maintain, more natural, or better looking, nor is it better for plants. All the specialty plant substrates are large grained, because plants grow more easily in a substrate that doesn't compact.

 

[Dale_I]

The truth of the matter is that UGF or not is a matter of personal choice. Sand, gravel, river rock, beads, bare tank, etc, is a matter of personal choice. Let any tank sit for any length of time and stir up the substrate and it's a mess.

The aquarium hobby is truly compromise in every facet. A case could be easily made that taking fish out of their natural habitat and inserting them into failing partial eco-systems (at best) for nothing more than personal enjoyment is cruelty.

Tank maintenance is not optional if you want a healthy environment for your fish. Be it cleaning the top of sand or using a gravel vac on your UGF.

I agree that UGF is old school, but that certainly doesn't mean it doesn't work if done properly. Anything done poorly has issues and nothing is un-reversable.

 

[Fishguy2727]

Almost all the fish we keep in tanks are form waters with sand or finer as substrate, not gravel. Much more natural.

Sand keeps debris on top and it either keeps moving until the filters grab it or collects in a couple piles for easy removal. Much more cleaner.

Sand doesn't compact, at least sands made for aquarium use. Cheapo sands form hardware store, maybe. Plants thrive in it. Not all specialty plant substrates are gravel size.

If you don't have to maintain your filter but once a year, it isn't doing much. It's whole job is to collect debris for you to remove from the system. If this isn't happening it's not filtering.

 

[jpchin]

here are some pics of my aquarium ugf. it's run by 2 power heads. the pvs pipe has holes on the bottom that sucks the water through the grid. the nice thing about this is that i can stick the wand between the pipes to get the gunk out when i do weekly cleaning. it's been set up for 10 months now. i have about 2-3 inches of small gravel on the bottom. the tank is 45 gals. it's 56 inches long and about 23" wide. i have alot of bottom surface that bb has grown on. no ammonia problems since it's cycled. i have about 35 live plants that are doing great. i have rams, dwarf gouramis, glo fish, sailfin mollys, and sa bumblebee cat fish.

 

[ashleynicole]

The other thing about UGF is, you never really now how well the water flow is, and you can get dangerous pockets of anaerobic bacteria underneath. two of the pet stores around here that still use them and I refuse to buy from them, because when you walk in the store they always have 2-3 of their tanks marked off due to disease, fungus, ich or whatever. It is a locally owned store. Honestly the petsmart in my area has much more knowledgeable employees and cleaner tanks than the two locally owned fish stores.

There is superior filtration through a HOB filter that you can see the water being pushed through efficiently. You never really know how well an UGF works. A sponge filter is better than an UGF if you really want more biological filtration in the tank, at least that you can take out and rinse and it keeps the gunk out of the substrate.

 

[Fishguy2727]

You shouldn't get toxic pockets with UGF, even if you had no pump running them. Gravel is course enough to passively allow oxygen to the entire gravel bed.

And a local shop recognizing disease and refusing to sell that to customers is a good thing.

 

[ashleynicole]

Yes but why does this shop always always always have diseases fish? Where are they buying from and what does this tell me about their water quality? I've tested the water from.the shop when I bring my fish home and it is always super high in nitrates. They apparently aren't doing maintenance.

 

[Bubble_B0y]

at the end of the day, it all comes down to weekly maintenance.

Any filter (if not properly maintained) can become ineffective and inefficient.

The UGF is no different - keep up with the regular servicing and you should be fine


If one was going to use an UGF, I'd recommend a powerhead driven UGF; preferably a reverse-flow. This combined with HOB/canister filters for mechanical filtration would be a good combo.

As stated in early post, Air pump driven UGF are worthless

 

[Fishguy2727]

That is a different story. High nitrate=low water quality=stressed/diseased fish. Another issue can be the supplier they are getting them from, but in general they should have control over this.

Yes, any filter can become neglected and turn in to a nitrate factory. But like I said earlier, it is a lot easier to undo this with a HOB or canister than with an UGF.

Just go with sand and be done with it. I could never see myself doing gravel again except with huge fish that will just kick it up into the filter.

 

[Dale_I]

I don't see any benefit in telling people what to do. I would hope we are all intelligent people that can sort through the issues and decide for ourselves what level of involvement we are willing to dedicate to our hobbies. I have a saying in my business that applies here, "Educate an intelligent man and he will make the right choice". It may not be one you agree with, but I don't think you are telling me that I have to change my river rock tank or gravel tank to sand because you like it better. Besides, my 3 and 5 year olds would be crushed if the pink and green colors came out of the tank, or if Arial wasn't sitting on Prince Eric's ship anymore.

I think it may be beneficial to stop the degradation of the thread and get back to the question at hand:

Hats the purpose of an ugf? Is it beneficial enough to actually use one? Can you have live plants with a ugf?

To answer the questions, the purpose is to provide filtration. Bacterial filtration as the water is drawn through the substrate and mechanical as it holds material until you remove it with a gravel vacuum.

Yes, they still hold beneficial results enough that some choose to use them. However, advances in technology have allowed other filtration choices to be less time demanding and some (like me) use a combination of the two.

Yes, live plants can survive very well in a UGF environment.




It should be noted that pictures of the above coffee table tank contain a non-standard UGF system normally used in reverse flow appliations. Standard tank UGF filters normally contain a plate that fits to the bottom of the tank with draft tube(s) pulling (or pushing in reverse flow operation) the water with use of a power head. Very low efficiency units will use a bubbler to create the draft, but the flow created by a draft bubbler is insufficient to maintain a volume that would make a UGF operable.