Switching from 3.5 gallon to 10 gallon - can I just move the filter?

[Linda N]

I have a 3.5 gallon cycled tank that has a few red cherry shrimp and a few pygmy corydoras. It has a sponge filter in one corner - probably 3 inches in diameter and 4 inches tall. I also have the HOB filter that came with the tank. The water regularly tests 0 ammonia, 0 nitrites and minimal nitrates and the inhabitants seem to be doing well. I change out half the water once a week and midweek will do 1 gallon of water switched out. I want to upgrade them to a 10 gallon tank so I can get a few more pygmy corys as I just love them. Can I just move the two existing filters, gravel, wood and live plants (and the snails that snuck in on the plants) to the new (still to be bought) 10 gallon and not do a cycle? Biological load will not be much more - am hoping the existing bacteria in the 2 filters and gravel will allow to just move everything and not spend time cycling.

 

[Guppylover3x]

I have a 3.5 gallon cycled tank that has a few red cherry shrimp and a few pygmy corydoras. It has a sponge filter in one corner - probably 3 inches in diameter and 4 inches tall. I also have the HOB filter that came with the tank. The water regularly tests 0 ammonia, 0 nitrites and minimal nitrates and the inhabitants seem to be doing well. I change out half the water once a week and midweek will do 1 gallon of water switched out. I want to upgrade them to a 10 gallon tank so I can get a few more pygmy corys as I just love them. Can I just move the two existing filters, gravel, wood and live plants (and the snails that snuck in on the plants) to the new (still to be bought) 10 gallon and not do a cycle? Biological load will not be much more - am hoping the existing bacteria in the 2 filters and gravel will allow to just move everything and not spend time cycling.

Hi and welcome to the forum.

It is recommended you take the filter and filter media over whenever upgrading tanks. This prevents the cycle starting again, if the filter is suitable and big enough for you new tank I’d definitely recommend moving this over.

The beneficial bacteria is built on this media which makes it important to the cycle.

You can check the water capacity your filter can manage on the instructions, online, or via the direct company.

Best of luck.

 

[Linda N]

Thank you - I was hoping that was the case. I will move all of the gravel, plants and wood to the new tank along with both cycled filters.

 

[Colin_T]

Can I just move the two existing filters, gravel, wood and live plants (and the snails that snuck in on the plants) to the new (still to be bought) 10 gallon and not do a cycle?

Yes.

Put the new tank wherever it is going.

Set the new tank up with gravel, ornaments, plants, etc.

Move the water across too. You want the new tank to contain at least 25% of the old original water and 50% is better.

Put the filters and fish into the new tank. Get the sponge filter running, then top the tank up with clean dechlorinated water.

Turn the power filter on.

Do not feed them until tomorrow.

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If you haven't bought the tank yet, try to get the biggest one you can.

In Australia and the US there are several different sizes of 10 gallon tank. I'm not sure what they have in the UK, but if you can get the biggest tank you have room for and can afford, it gives you more space for more fish and shrimp.

eg: in Australia we have tanks that are 2ft long x 10 inches wide x 12 inches high, and we have tanks that are 2ft long x 12 inches wide x 12 inches high. We can also get tanks made to size and I know a number of people that have tanks that are 2ft long x 18 inches wide x 18 inches high.

These tanks all take up a similar amount of space but the tanks that are wider and higher hold a lot more water, so it's better for the fish.

 

[Linda N]

Well I went in a slightly different direction. Instead of getting a 10 gallon to move the residents of the 3.5 gallon to, I got a 20 gallon. I'll move everyone from the 10 gallon I already have into the new 20 gallon and then everyone in the 3.5 gallon will move to the 10 gallon I already have - LOL. I have another really small tank with a few Endler's in it who will join the pygmy corys and red cherry shrimp in the 10 gallon so I'll only have 2 tanks to maintain instead of 4. I'll put the media that came with the filter for the new 20 gallon into the filter that's already in the 10 gallon so it can be colonized by bacteria in the existing tank.