undergravel filtration question

Folks:

I am asking these questions in order "to log other folks experiences into my brain" instead of the "hard way".

The following questions are based on the literature as well as my thoughts derived therefrom.

1) A portion of the literature suggests that UGF's expedite growth via warmer roots.
Is this a valid assertion?

2) Should someone wish to install an UGF is "suction through" or "discharge through" the UGF appropriate?

3) I really do not understand why in the days of wet/dry, Pythons, etc why an UGF is necessary.
The potential of anaerobic bacteria production, methane gas production , etc. compared to "warm roots" is nothing.

TR
 
1) Are you planting the tank and that is why you are asking about warmer roots? If so it does not help warm the roots. Planted tanks should have a fine substrate, some mix with soil or other specialty substrates that are not UGF compatible. There are special substrate warming heaters, but I have heard they don't make much of a difference.

2) I think between the two that Reverse UGF (RUGF) is a tad better. But again, I wouldn't use them. I wouldn't use them if you gave them to me. In fact, I threw out two this morning cleaning out the basement.

3) UGFs are far from necessary. Most people don't use them anymore, and for a reason. Most have moved on to more advanced and better filtration systems that are less maintenance and less risk of problems.
 
reptileguy2727 said:
I wouldn't use them. I wouldn't use them if you gave them to me. In fact, I threw out two this morning cleaning out the basement. ...
... UGFs are far from necessary. Most people don't use them anymore, and for a reason. Most have moved on to more advanced and better filtration systems that are less maintenance and less risk of problems.
Click to expand...

I appreciate the response reptileguy2727!

I am anticipating setting up a very, very large tank next year at my offices and am trying to "do my homework".

Hence I very much appreciate your comments which are based on your experience.

TR
 
How big?
What do you want to go in it?

My 150 has just a Fluval FX5. It is doing very well, but as the fish continue to grow I will probably need another filter, just to be safe. These are definitely the way to go, unless you can afford the high end Eheims.
 
Boy does this thread contain a ton of misinformation. Where to begin....

1. RUGF is the way to go. But you need to add a 2nd filter such as an HOB. The RUGF will keep particles suspended in the water and the 2nd filter will pull them out. The second filter should be loaded mostly for mech filtration. As noted above the PH for the UGF/RUGF need to have its intake sponged to prevent debris being sucked into the system where they can become trapped under the plate.

2. Despite modern technology, the ugf/rugf are still the best bio filter there is. Why? because your entire gravel bed is your bio media. I have never seen a filter with an equal volume of biomedia available.

3. An RUGF, because it isnt sucking debris down into the gravel will actually reduce maint. as the need to vac is reduced. But you must use a secondary mech filter.

4. UGF/RUGF flow rates should be fairly slow. The slower flow means the oxygen in the water as well as the ammonia and nitrites the bacteria need to eat will be in contact with the bacteria longer as it passes through the gravel. If one needs more current, add a PH or filter for it.

5. To work properly the UGF/RUGF needs a medium sized gravel with a depth of 3 or so inches. Too little or too much will not work efficiently and too fine a gravel will impede the flow through.

6. All filters should be maintained and cleaned regularly, under gravels are no differnt and no more or less work to keep clean.

The one downside to this filtration is the uplift tube(s) and the PH driving them are hard to hide if you are trying to create a display tank with minimal equipment visable.
 
The volume may be higher, but the efficiency is still lower. Just because it is there does not mean it is all covered in nitrifying bacteria. A given bioload only needs a certain amount of nitrifying bacteria, more media for them isn't going to help. The best biological media is Biowheels because they expose the nitrifying bacteria to atmospheric oxygen (MUCH more than what is in the water) without the debris buildup problems of bioballs.

Low flow allows dead spots and can lead to anoxic bacteria developing. The area of the bottom of the tank is VERY large and it takes a lot of flow to keep oxygen levels up throughout the entire gravel bed. Water will take the path of least resistance and that means most of the bed will be bypassed as the water flows through shallower areas of gravel and around clogged areas. And if you have cichlids and they dig a pit down to the UGF plate, forget about any flow through the gravel.

Yes, all filters need to be properly maintained, but UGFs are more work. Weekly vacuumings are REQUIRED. Other filters need it weekly to monthly.

You still NEED another filter even if you have an UGF. So you can either buy a HOB, or you can buy a HOB, and an UGF, and powerhead(s), and spend more time cleaning, and hope you are not going to have problems in a few years. The choice is yours.
 
I can say that I have had a UGF for the past year now and had absolutely no problems at all with them with proper gravel vacing, like should be performed in any tank no matter the filter choice.

Recently switched to a RUGF just to see if there was a noticeable difference and my substrate has never been clearer. I completely agree with twotankamin though, a HOB should be used otherwise the debris will be stagnant in the water.

Too many people are misinformed about UGF's. They arent as bad as people make them out to be and many use them and have successful tanks.
 
The best biological media is Biowheels because they expose the nitrifying bacteria to atmospheric oxygen (MUCH more than what is in the water) without the debris buildup problems of bioballs.
Click to expand...

Tell you what- set up two tanks side by side- one with rugf and the other with an Pmperor or Penquin. Get em cycled and stocked and running well. Then to simulate what could happen if you go away for a day and the power fails, unplug both filters for 12 hours. Which tank do you think will still have most of the bacteria alive?

A biowheel is a great bio media for the limited space it occupies. The wet dry aspect just means that more bacteria will likely live on it than other places in the tank. It is by no means the best bio media. Any hard surface that gets a regular flow of O and ammonia/nitrite will attract bacteria.

Two of the fishkeppers I most respect and who's advice I seek both use undergravel filters. One is well known on the net, has kept multiple tanks for many decades and writes articles available online and in fish mags. (I would post a link to his excellent article on under gravel filters, but AC doesn't permit links to the site it is on.) The other just gave up his final tank recently after keeping and breeding fish for about 55 years as well as owning several fish and pet stores. His last tank was a planted 135 with an RUGF.

The thing about the bio bed in an undergravel filter is not that it all has to be used, but that it offers the greatest possible potential volume/area on which the bacteria can live. Even in a non ugf/rugf tank, a fair amount of your bacteria is on/in the gravel.

The amount of oxygen in the water in a tank where the surface is constantly being aggitated are about equal, same for co2 levels. These gasses will pass in or out working towards equilibrium.
 
There is no where near the concentration of oxygen in water as in their air, that is completely false.

Bacteria will live where it is best for them. Since the temperature in the tank is the same everywhere this is not an issue, although it would be if one area was much warmer than another. So, so far all areas are equal. They will live where there is the most oxygen and food. This means in the filter media where water is constantly supplied, so most bacteria will live in the filter. If you have any type of wet/dry this is even more true because there is SO much more oxygen there. They will live where it is most ideal. This does not mean an even distribution throughout the tank. Not any hard surface will have the same amount of bacteria as another, there are other factors besides surface area that greatly affect the distribution of nitriying bacteria in the tank.

With UGF more debris builds up in the gravel. And since a lot of your nitrifying bacteria are in the gravel it is even more vital that the weekly vacuumings are done to prevent the debris from choking out the underlying nitrifying bacteria, as well as long term nitrate problems.

I never said they don't work. They work, I would never debate that. In my experience most of the people who still use them have been in the hobby since UGFs were the best thing and are used to them, trust them, and perhaps are better at using them than newer hobbyists. It is simply that now there are better options, plain and simple.

In my experience tanks with UGFs are more prone to problems, from water quality and parameters, to disease and other issues. This is most likely at least partly, up to entirely, contributed to by less than ideal maintenance. But this even shows why they are not a good idea. It takes less screwing up and not keeping up with your maintenance to cause problems. What percentage of other filters cause problems for people? What percentage of UGFs end up causing problems for people? More with the UGF that is for sure.

The 90 at my work used to have UGFs. It was properly maintained. Even so, I added a canister and a little while later removed the UGFs and the gravel (replaced with crushed coral). When I did the tank looked like it was full of raw sewage. The visibility was literally about one inch. And yet there was no issue with the tank re-cycling. So much bacteria had colonized the canister that even the 'superior' media of the gravel itself did not matter, the nitrifying bacteria were mostly in the canister.

My tanks are all sand. It is much more natural, looks much better, and the least maintenance. Even without an UGF gravel traps a lot of debris. The fish seem to like it more too. It doesn't trap any debris and keeps debris on the surface. This means the flow in the tank keeps it moving until the filters grab it. This is the best option for substrate setup in my experience, unless you have live plants. I do, but only hardy stuff. If you really want to get into live plants that is a different subject.
 
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