Under Gravel Filters

[Osian]

I've was thinking of placing an undergravel filter in a tank but at the shop they told me they wernt very popular, also i've noticed a few post around the internet where people mention they're removing them. I just cant find out why there's not popular?
Also can i use it with sand and a mesh (geotextile mesh) to stop the sand falling though and clogging up. Or will the send still compact to tightly on top?

I was thinking of placing it in a betta tank as i though the flow would be very minimal and as it would only be a singal fish in a 10 gallon tank. (still not happy that his tank is only 4 gallons)

 

[Colin_T]

undergravel filters are fine as long as you gravel clean them. A lot of people don't gravel clean their tanks and the filters clog up. Then they complain about them not working properly. Any filter that isn't maintained regularly will also clog up and cause problems.

In tanks with lots of rock or wood it is hard to gravel clean the entire substrate. This causes dead pockets to occur and is one good reason not to have an undergravel filter. In this type of tank a thin layer of gravel and an external power filter is a better choice.

For a tank with only a few bits of rock or ornament an undergravel is fine.

Don't use sand because it compacts. Just use a fine aquarium gravel.

 

[waterdrop]

Hi Osian,

A while back I was trying to get some of the experts to help a member spidergravy re an under gravel filter and BTT have some responses. Here they are in case they are of interest:

http/www.fishforums.net/content/forum/23...-Cleaning-Help/

Also, Colin, maybe it was you that I was referring to in one of those questions re simply placing a siphon hose directly up against the undergravel plastic grid to get better cleaning out? (long shot I guess, but worth asking you)

Osian, I don't know if I'm right about this but I sort of get the feeling that the undergravel design has a bit more pronounced problem with the trade-off between debris holding valuable bacteria and debris clogging the flow. The area under the grid is a large blank space that can fill up with muck, clogging the flow. If you manage to vacuum it all out you can start a mini cycle from loss of bacteria. All filters have this problem (the assumption being that the aquarist is not performing maintenance often enough.) With undergravel, the problem is more "out of sight, out of mind" and harder to do when you do get to it. But, if you are the type to be really good about maintenance and you figure out a technique that really works to clean out the undergrid part and the gravel itself builds up a large enough bio-filter then it could work ok. I've always thought part of the problem would be that gravel, even though a large length by width area, would be less surface area for the bacteria than the sponges or bio-media of other filters - but your application sounds like this probably isn't critical.

Thoughts Colin?

 

[Colin_T]

To clean the gunk out from under the filter plates simply push the gravel cleaner all the way down into the gravel until it hits the plastic plates. Then leave it there until the water comes up clean. Lift the gravel cleaner up and move it to another spot and repeat the process.

If you do regular gravel cleans then the gunk doesn't build up under the plates and the beneficial bacteria develop in the gravel. Clean gravel also allows the water to pass through it easier and the water will be cleaner because there is less gunk that the water passes through.

All filters are the same, if they are dirty the water can pick up all sorts of nasties when it passes through the dirty filter material. Clean filter media means cleaner water.

You can have an ammonia or nitrite spike if you do a massive clean on a dirty tank or filter. This is because you remove some of the good bacteria when you clean the gunk out. In a healthy system the bacteria will replace their lost numbers within 24 hours. They divide every couple of hours so it doesn't take long to rebuild a population.

The best way to clean a tank is to drain out 1/4 to 1/3 of the tank water and gravel clean as much of the tank as you can. Normally you only manage to clean about 1/3 of the gravel. The next time you do a water change you gravel clean another 1/3. And the next water change you clean the last 1/3. Then you start all over again.
By only cleaning 1/3 to 1/2 of the gravel you can guarantee you aren't going to upset the filter bacteria too much. And if you gravel clean every water change, the gravel will stay clean and you won't get much gunk building up in it.

The other thing I recommend is not feeding the fish on the day of the water change. This means there is less ammonia to break down and the filter bacteria will have time to rebuild their numbers without having to deal with surplus ammonia.

Undergravel filters do have a huge surface area to hold bacteria. All the gravel in the tank becomes the filter. It takes a lot of foam blocks or noodles to cover the same area.
A drawback to U/G filters is they used to be run on airpumps and the pumps make a noise. However, many can also be run with a water pump. The Aquaclear water pumps are great for this purpose. They have a little V shaped adaptor to sit on top of most U/G uplift tubes. They suck the water through the gravel and under the plates before pumping it back into the main part of the tank. An air attachment can be added to them for more surface turbulence. Or you can angle the outlet towards the surface to increase surface turbulence.
When operated by an air pump the water flow through them was pretty slow. Using a powerhead fixes that problem and the noise created by an airpump.

Not all U/G filters are capable of being operated by a powerhead/ water pump. Some that are designed for small tanks can only be run with an air pump.

 

[T1KARMANN]

undergravel filters are a thing of the past time to move on

their are much better solutions on the market now for filteration

undergravel are from the 80s

 

[OohFeeshy]

If it's betta-friendly you're after, then I probably wouldn't go for a UGF. There's a fair amount of current, plus lots of air bubbles, and you can't always cut the flow down well. Not to mention any problems with cleaning and the large volume the system takes up. Something like a HOB might be better, the flow is adjustable and you can cut the current down even more (there's a thread in the FAQ section), and the media is easily accessible to clean.

 

[Colin_T]

undergravel filters are a thing of the past time to move on

undergravel are from the 80s

actually they are from much earlier than that. They are children of the hippies and can be found back in the 60s.

 

[T1KARMANN]

i ment people stopped using them in the 80s

 

[Colin_T]

oops, sorry, I thought you meant they appeared in the 80s

 

[waterdrop]

yup, I had a big (for me) undergravel in the mid-60's but most of my tanks had HOB or internals. trouble was, looking back, I didn't a bit know how to really maintain really any of those properly. that's why this is all so fascinating to me, a lot must have happened in the 80's when I wasn't tuned in at all.

 

[Colin_T]

Yep back in the 80s they had the gravel cleaner. It might have appeared before that but it didn't appear here until the 80s. When I first started work in the LFS they would have been lucky to sell one or two gravel cleaners per month. They were covered in dust and no-one knew what they were. After finding out what they were and how to use them, I started selling them by the dozen. Well almost. But sales picked up pretty quickly once people knew about them. We actually got to a stage where the boss was bringing in huge shipments of them every month and we were selling out within a couple of weeks.
We had a couple in the fishroom to use and also to show people how they worked. As soon as people saw the gunk coming out of the gravel they would buy one. And they weren't just bought by people with U/G filters. Everyone who had a tank bought one because they could clean the gravel without having to remove it from the tank. That used to be a horrendous job. Every 6 months you would drain the tank and put the fish in a bucket. Carry everything outside and start washing.
Boy I wish I had invented them. Heck, even if I had a dollar for everyone I sold.

 

[waterdrop]

Now wait a minute. You must be referring the the python type thing. I had a gravel cleaner back in the 60's and of course we used tubes to siphon then too. But the gravel cleaner was one of those ones where you squeeze the suction bulb at the top and it just pulls the water up the stiff plastic tube and dumps it over into a cloth strainer bag. Those I thought had been around forever.

 

[Colin_T]

The tubes with the squeezy pump thing on top was a fuel siphon originally. Then people used them to drain water from their tanks. They have been around since cars first ran on fuel.

The gravel cleaner has two parts. (1) A length of plastic hose for draining water, and (2) a rigid plastic tube about 12 inches long and about 2inches in diameter. The tube attached to the hose and goes into the tank. Water is siphoned out of the hose and you push the tube into the gravel to suck up the gunk.

The Python siphon has been around for a while but not sure how long. Certainly as long as the basic gravel cleaner. From my understanding it is a gravel cleaner with a second hose attached to facilitate refilling the tank after draining. Someone correct me if I am wrong because I have never had one.

 

[Lateral Line]

But the gravel cleaner was one of those ones where you squeeze the suction bulb at the top and it just pulls the water up the stiff plastic tube and dumps it over into a cloth strainer bag.

I remember those. Never had one as I always did gravel cleaning when doing a water change so used a wide ugf uplift tube connected via a bored cork to my syphon tube thus the crud was straight out of the tank at the same time as the water.

I used ugf's from the mid '60's until perhaps the mid '80's by which time I had changed over to external canisters on all of my tanks, (apart from fry tanks of course - sponges).

The betta comment above is also good, betta's like a fairly still surface environment.

 

[waterdrop]

The tubes with the squeezy pump thing on top was a fuel siphon originally. Then people used them to drain water from their tanks. They have been around since cars first ran on fuel.

The gravel cleaner has two parts. (1) A length of plastic hose for draining water, and (2) a rigid plastic tube about 12 inches long and about 2inches in diameter. The tube attached to the hose and goes into the tank. Water is siphoned out of the hose and you push the tube into the gravel to suck up the gunk.

The Python siphon has been around for a while but not sure how long. Certainly as long as the basic gravel cleaner. From my understanding it is a gravel cleaner with a second hose attached to facilitate refilling the tank after draining. Someone correct me if I am wrong because I have never had one.

Interesting, the term "gravel cleaner" is clearly synonymous in your mind with what I think of as a "gravel siphon", "gravel cleaner" being stuck in my mind as the "hand fuel pump with cloth bag" we have been mutually describing, lol. Its becoming more clear that the young hobbiests starting 80's a later think of "gravel siphons" as "gravel cleaners" and the old piece of equipment has been relegated to the curiosity shelf. (The fuel pump style, both hand-squeeze and battery-operated are still available, as I ran across them while researching the Python, but have clearly faded greatly in popularity it seems.)

A derth in Perth of a siphon named Python?
I, the "re-beginner" have a 50-foot one of these and have used it twice. I mostly got it because I knew I was going to need a length of clear tubing for siphoning anyway. I actually wouldn't describe it as "a second hose attached", but as a single tube, gravel cleaner tube on one end, then long clear tube going to faucet/drain. Then the clever bit is a green plastic tee valve, your long tube coming in to it from the side. The tee attaches to the faucet. The drain end of the faucet has a skirt that clicks up or down to engage a one-way valve allowing faucet flow to create a vacuum suction in your long siphon line or in its other position to send temperature mixed tap water back the same long line to the aquarium. There is a stop/go valve at the aquarium end as an extra facilitator to help a single person walk back and forth to the distant aquarium and do the operation although I find that particular bit has been unneeded by me as once the siphon is established, it holds ok even if I turn off the faucet. Also, since I've now gone on about it, the nice thing about this company as a whole is that they provide a wide range of parts for mix-n-match: an array of gravel tube lengths, an array of long hose lengths, an array of adapters. All in all a very clever product, adding a couple of nice little conveniences to water changes.

(apologies, I know you, Colin, have probably already read descriptions and the others of probably even have one!) I got carried away again.. ~~waterdrop~~