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Combine a Sponge Filter with an Undergravel Filter?

13K views 7 replies 3 participants last post by  Ridewithme38 
#1 · (Edited)
Ok i know alot of you guys don't like undergravel filters and believe they are just breeding ground for dangerous and bad bacteria....BUT if you bias against UGF's odds are you won't be able to answer my question anyway....

Soo, the old story goes, my daughter went to a fair and won two goldfish, it came with a tiny tiny *about* one gallon fish carrier, within 2 days one of the goldfish died....got online and read this is a ridiculously small tank for ANY fish....so rushed out before i was financially able to buy a 'real' tank for the goldfish that was left and bought an Aquaview 360 tank(3 gallon)...i know its still ridiculously small, but within a month or two i'll be upgrading to a 20 gallon long tank, but honestly, hoping i'll be able to upgrade to Platy and Guppy by then

Soo. onto my question, the Aquaview 360 came with an undergravel filter,So through research i realized the process a UGF and a sponge filter use are sorta compatible...an airline runs down an uplift tube and draws water up with the bubbles(or into the sponge with a sponge filter)....Can i just add a sponge to the airline in my UGF's uplift tube and have it operate as a sponge filter AND an UGF or is there much much more to the process?
 
#2 ·
Well your best bet is just to get a airline splitter and a sponge filter to run both, but as for it your idea will work, sure it will to a point. It all depends and the actually placement of the sponge, it should be place below the outflow of the air so the water still gets drawn through it. But you will still need to keep an opening through the sponge to the UGF so it can still draw water that way easy. The problem really arises in this situation the water will have an easier time going through one or another so the other one will be under utilized with water flow.

I'm just kind of guessing here on what your setup plan looks like, it might be easier to say nay or yay if you gave a bit more description or a drawing.

BTW welcome to TFK

Also I hate UGF but I don't let that get in the way of the mechanics I enjoy solving :)
 
#3 ·
Ahh, lets see if i can explain (although i wasn't aware the sponge had to be below the airstone, so that may change it)

Basicly, this is my tank...


That center tube is between 2-3" wide with a airhose running down the center connected to an airstone at the very bottom

My thoughts were, to add a larger airpump, i was thinking TopFin 3000 airpump, to increase the air power then add a sponge right above where the airstone is connected...but now finding out the sponge would need to be below the airstone, would it work if i just replaced the airstone and added the bigger pump with a small sponge filter like this one or would that make the undergravel filter not work?

 
#4 ·
Most air driven filters work on the concept of displacement, basically the water in the intake tube is displaced by the air forcing the water up and out of the tube, causing the lower part of the filter to have a decreased water pressure in it. Since liquids and gases like to equalize pressure this forces water to enter the filter part of the filter and continue the cycle. This is why a filter attached above the air wouldn't work so well.

As for the issue of attaching the filters together its going to take alot of work to get the two to fit together and keep things tight fitting. If you can get the two to fit together tightly and allow water to flow through both and attaching the air to the sponge filter should work. But you have to remember the water will always try and equalize through the filter that is easier to flow through.

Also drilling through the bottom of those sponge filters is probably not an option as I believe the base is filled with lead or sand.
 
#6 ·
Yup drawing is right on it shouldn't work in theory because the water inside the inlet tube is higher pressure so the water probably wont flow through the attached sponge filter. Since your looking to upgrade I would just use the sponge filter and UGF in tandem hooked to different air supplies (or split from the same air supply) the benefit to this is you are planning to upgrade tank size anyways, so you can just move the sponge filter over to the new tank when you get it and you will have alot of the beneficial bacteria you already need so you should only go through a mini cycle. And then you already have the filter you need for the new tank and can keep the UGF inside the 3 gallon if you wanted to keep that one going or use it as a hospital tank.
 
#7 ·
Sponge filters work by using air flow to pull water though the sponge. Placing the sponge in the way of the air (as in your drawing) simply will not work. I have heard of adding a layer of sponge on top of the UGF, under the gravel. Inasmuch as this 3g is a temporary, I suggest you simply use the UGF alone. Just be sure and use a gravel siphon weekly to keep the filter media (gravel!) clean - then it will work great.
Although there are many detractors and ney sayers, the UGF has been an effective and economical filter for 40 years that I know of. However, it will fail badly if neglected and the detritus builds up in the gravel.

Now, you speak of guppy's and platy's in your 20g. Be advised that goldfish are not tropical's - you'll need a heater for the tropicals and not the goldfish. goldfish like cold water, while the tropical's require a steady 75-80 deg. F.
 
#8 ·
Now, you speak of guppy's and platy's in your 20g. Be advised that goldfish are not tropical's - you'll need a heater for the tropicals and not the goldfish. goldfish like cold water, while the tropical's require a steady 75-80 deg. F.
When i got the goldfish i had absolutely no knowledge of fish...i figured, OK this goldfish will die in a week so everything i buy i'll buy for the 'next' fish, which are most likely going to be Guppy's and Platy's...i didn't realize then that goldfish can live 20yrs+ and grow over a foot!

Hopefully i should be buying (Now) a 29 gallon tank starter kit(i can't find a 20 long tank as a starter) within a couple weeks and have it up and running and fully decorated by the end of October or mid-November...IF the goldfish is still around and kicking in its 3gallon by then,i'll have to see if i can find a LFS that can take him or maybe a friends koi pond?...i just don't have the room for a foot long fish, i can't go any bigger then the 31 inches(Length) a 29 gallon takes up and that's not fair to a goldfish
 
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