# 20 Gal diy sponge filter



## Stages (Apr 13, 2010)

So, I just got a 20 gallon tank today and I'm wondering how much surface area I need for a diy sponge filter. Before I measured it, I thought the tank was 10 gallons (I got it for free off Freecycle, and the guy that gave it to me thought it was 10), so I made a sponge filter for about that size.

I have a sponge filter that's about 2.5 inch on each side, and it's buried under a light layer of gravel to weigh it down. I have it hooked up to an air pump that's rated for 20 gallons, and no air stone (the tubing I'm using for the lift tube is just a little too skinny for the air stone to fit in). The gravel layer is about an inch and a half thick, and it's moderately planted and has several PVC pieces for hiding. I have my betta (Franklin) and 6 cories in the tank for now. 

I'm starting the process of cycling the tank, and I know having the gravel and filter is absolutely crucial. My question is, what size sponge should I have for the filter? And is it ok to have it buried under gravel?

Also, on a side note, Franklin got hurt when I transferred him to the cup to switch tanks- part of his fin got stuck in between the tank wall and the cup and some came off. He's acting fine, but do you think I should switch him back into his little tank (1 gallon) for a while to make sure his fin heals ok?


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## xxabc (Feb 1, 2010)

I got a sponge that was from the Pet-Store. It was a sponge that was actually rated 10-30 gallons, so if you see anything like that, I would trust it being for 10-30 gallons. However, in size, it's really not that big. Or, I would've imagined it being bigger. 

If you're not looking for that type of sponge, and would rather go to the dollar store, try dropping off at Petsmart and/or Petco and looking at the size of it, and imitate as BEST as you can. 

See if the cories do not stress him out at all. Be good on water changes and make sure the water is heated. But, if you want to use aquarium salt, he'll probably have to transfer back to the 1 gallon. I don't think cories are good with salt. If you _do_ want to transfer him back, just make sure you can safely heat the 1 gallon and still perform daily water changes (daily mainly to help with healing) to help him heal. 

What I would do is see how he gets along with the cories, but it's your shot.


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## Mister Sparkle (Apr 13, 2010)

I wouldn't recommend burying your sponge in the substrate. You can wedge it up against the wall (lightly) with one of the decorations, if it won't stay in place. 

It sounds like xxabc has a Lee's triangle sponge (just a guess). It's a good one. It fits perfectly in the corner, where it is easily hidden from view. And it'll definitely filter a 20-gallon. There are some bigger ones you can get which are held in place with suction cups...and bigger is never a bad thing in filters. With 20-gallons to work with, you can still maintain a relatively motionless surface. I've really come to appreciate the one's made by Xinyou co. They aren't very instructive, but the products work very well.


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## xxabc (Feb 1, 2010)

I actually don't, although I DID want one. They don't sell it here, so I had to go for the regular rectangular sponges. 

I want another sponge for the sponge filter. Just for aesthetic looks. Ugh...hahaha.


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## Mister Sparkle (Apr 13, 2010)

If you can find the Xinyou ones...they are awesome!


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## brancasterr (Mar 30, 2010)

Hmmm, I have a regular dry mount filter thats rated for 5-15 gallons. I'm wondering if I should change to a sponge filter or add one in addition. They seem to be pretty amazing.


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## Mister Sparkle (Apr 13, 2010)

In my 15-gallon, I run a 40-gallon rated external AND a 40-gallon rated sponge. My water is so pretty it's not even funny!


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