Changing Filter

[Hunterprey]

Hey sup guys, can use a lil help, still new to the hobby

Im planning on getting an underwater filter to replace my current filter. One that is compatible to a 20-40g tank. I read in the topics here in this site that the good bacteria are in the filter. Im thinking of getting the new filter and let both my old and new filter running so the new filter can cycle. Would that work? Can you just replace your filter after your tank has cycled for 5 1/2 weeks?

Im planning to transfer the new filter, water and gravel (If I have to, I'd rather get new one) from my 20g to my 40g that I will get in like a month or so, so I don't have to do the whole cycling thing again, Will that work too?

Appreciate the help, this site has been very helpful

 

[drobbyb]

If you run the filters both in the same tank, the bacteria will colonize the new filter. It takes about 6 weeks.

 

[Hunterprey]

Thnx very much, so it should work then.

 

[arobinson1984]

I personally wouldnt get an undergravel filter, they are old technology and are a nightmare to maintain.

If you are trying to save tank space you would be better with an external cannister filter

Andy

 

[waterdrop]

I agree with Andy. There's nothing wrong with the principles of undergravel filters but the execution of maintaining them properly is very difficult for beginners and often does not work out well.

~~waterdrop~~

 

[OldMan47]

Welcome to the forum Hunterprey.
I would expect an underwater, internal, filter to work fine in a smaller tank and move easily to a larger tank. I am talking about a filter like my Fluval 4+, not an undergravel filter. Cycling an undergravel filter and then expecting it to transfer easily to a larger tank will be disappointing. Because you will redistribute the gravel in the new tank on a new filter plate, it will not be in the well developed bed that it formed in the old tank and will take a while to recover its layer of useful bacteria.

 

[Hunterprey]

Thnx for the welcome

And Im sorry for the misunderstanding, I think I meant underwater, internal filter, coz i just bought a Fluval U3, it seem to work really good. Im running my Fluval U3 with the filter that came with my aquarium that's already cycled, just waiting for my new filter to cycle too b4 I transfer it to my new tank, should that work?
Thnx a lot for the help guys.

 

[OldMan47]

Be sure to test whether the new filter is cycled by using a bit of ammonia when you get it in the new tank. I had one that I ran side by side with another filter for a month. When I moved it to a new tank I got to find out the hard way that it was not ready. I then spiked the filter with filter squeezings and got it cycled fairly quickly but had to deal with 90% water changes for a few days to keep my fish alive. Unless you are determined to do this the easy way, without using the ammonia and testing, your method takes much longer than a simple filter clone would and is less reliable.

 

[arobinson1984]

Thnx for the welcome

And Im sorry for the misunderstanding, I think I meant underwater, internal filter, coz i just bought a Fluval U3, it seem to work really good. Im running my Fluval U3 with the filter that came with my aquarium that's already cycled, just waiting for my new filter to cycle too b4 I transfer it to my new tank, should that work?
Thnx a lot for the help guys.

That ok then

I thought you by underwater, I thought you'd got mixed up and meant undergravel lol

My fault

Andy

 

[waterdrop]

Yup, me too, I read the top post then read Andy's and got mixed up too. We always use the term "Internal filter" for the filters under discussion rather than "underwater," not that there's anything wrong with that as a descriptor, lol.

~~waterdrop~~

 

[Hunterprey]

LoL sorry for the confusion, I'll remember it now "internal filter"

And thnx for the tip guys, great help.