Can a 10-gallon filter be used in a 20 gallon tank?

Question

I'm going to move my tiger barbs from a ten gal. tank to a 20 gal. All I need is the filter, can I use the one I had for the 10 gal. tank?
Will it keep the water clear the same way it did in the 10 gal.?
Or do I need to buy a new filter?

Answer 1

You need to buy a new filter yes, but you don't discard the old one. You can just add on another ten gallon or 20 gallon filter even and will be just fine. The current filter will contain the benefical bacteria you need, and when you tack on a second filter, some of that will migrate to there. You would want additional filtration, but if all you have is tiger barbs, and NOTHING else, you probably will be ok for awhile if you can't get a second filter for now.

JV

FOLLOW UP:

In terms of your water being clear, if anything it'll be even clearer then before initially. You're taking the same population, and doubling the total water volume. The same amount of waste, because waste doesn't matter whether you're in the 10 or the 20, will still be a constant if you are using the same population. Constant meaning it's not going to go up or down just because you moved them. So more total volume to distribute the same amount of waste, at first water should be well clear. Then as you only have a filter rated at 10 gallons, waste accumulation will not be reached at some spots and begin to accumulate until you do your water changes, and possibly, later on the water will get a more cloudy appearence. You certainly are not going to hurt a thing using that ten gallon filter in conjunction with a second, just place the second filter on the opposite end where the first one is. I actually think you'd benefit more by having two filter then tank, then just a single one rated for the tank capacity. Filtration in excess of your tank size, 99% of the time is a great thing, unless someone's actually trying to use a massive cannister filter in something so small, like a 5 or 10 gallon tank, in which you'd create a massive current the fish would die from. Keep that old one and just add on a second one of at least 10 gallons or more and you'll be just fine.

Going without is going to cause problems down the road, and there really is no need whatsoever, unless broken to ditch the old filter for a newer bigger one.

Answer 2

You need a new filter. The old one is too small to work effectively. Problem is, all the beneficial bacteria is in the old filter. I'd run the old filter in the new tank, with the new filter too for several days, maybe a week. Moving the gravel from the old tank to the new one will help too.
More than likely, your old heater will not keep up either. While a 50 is fine for a 10 gal., it will hardly impact the temp of a 20. You'll need a 100 watt heater before it gets cold.

Answer 3

Depends on how populated the tank is. If you are keeping the same number of fish in the tank, and it's not overpopulated, then sure. Keep your old filter. The filter is not as important as some folks would have you believe. The important thing is regular cleaning and partial water changes. The filter is basiclly there to remove larger debris from the water, but the biggest polluter in a fish tank is ....the fish. Thier excrement usually sinks to the bottom, and siphoning it out of the gravel is important in any tank. If, sometime down the road, you decide that you need a bigger filter to help with the build up of leftover food, etc... then you can always go get one.

Answer 4

Yes you can use 2 smaller filters. You can actually get away with a smaller filter if you dont have many fish. But the filter sizes are pretty vauge. I would suggest you set the tank up with the 20, get it cycled. It will be OK for a few fish. Then save up for a good 30gal size filter and run both for extra filtering goodness. Ian

Answer 5

Everyone is answering this on the assumption that the filter you already have is the appropriate size for a 10 gallon tank. Maybe it is, but maybe it's not. Without you having said what size filter you have, this question can't really be accurately answered, so I'll just give you this. The rule of thumb is that all the water in your tank should pass through the filter at least four times each hour. But, in general, it is suggested to choose to go with the next higher flow rate. For example, a 10 gallon tank requires a flow rate of at least 40 gph (gallons per hour), so you would have a 50 gph filter that was good for a 10 gallon tank. But, if the filter you have now is rated 80-100 gph or higher, you don't need to get a larger one for the 20 gallon tank. If it's less than 80 gph, you need to get one rated at about 100 gph.

Answer 6

Theoretically you could push it if you did a lot of water changes. Staying with the ten gallon one will cause both you and your fish stress, i recommend getting a larger filter. Personally i get filters with an adjustable flow because you can get them larger than you need and turn down the water speed for more filtered water(to make up for a decreased flow the filter re-circulates water, making it cleaner). Plus when you decide in a year to purchase an even larger tank you may not have to worry about buying a new one.

Answer 7

It is always better to use a filter rated for a tank larger than you have than one that is rated for a smaller tank. The ten gallon filter will work in the 20 gallon tank but it won't work as well. It won't be as effective in the larger tank. Filters aren't that expensive, get a new one designed for a 20 gallon, even one rated for a 30 gallon tank would be better.

Answer 8

no because its not big anough to filter the whole tank, buy a 20 gal one or another 10 gal one you can have 2 x 10 gal ones.

Answer 9

New filter. I do have a 30 gl filter on a 20 gal tall tank with fancy goldfish but I would not do a smaller filter on a bigger tank.

Answer 10

I don't recommend it because the filter should be atleast 10 gallons more in capacity from the tank size. You could use it while cycling the tank and then add another filter.