# Upgrading filter



## bmoore09 (Nov 20, 2010)

So my son has a 20-gallon tank. He has a nice selection of fish in there, but I think he can add more (aqadvisor says he's at around 40% capacity). Problem is, he has a pretty low-range filter. It's an Aquatech 10-20, so I want to upgrade the filter so he can add more fish and make sure the tank has proper filtration.

The tank has been established for a while, so his ammonia/nitrite/nitrate readings are where they should be. But I know I can't just switch out the filters since all the good bacteria is in the smaller one. What would be a good strategy to make the switch? 

I was thinking that I would just run both filters for maybe 6 weeks so the new filter can build up the proper bacteria amounts. I can't leave both filters on the tank forever, as the tank is too small for that...but I figure for the short term it's ok. Then after 6 weeks go ahead and take the old filter off and the new one should do the trick? 
Or will that just create another cycle and raise my readings? I know I can't be the first person to do this, so any advice on the best tactic on the switch?

Thanks


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## KG4mxv (Oct 25, 2011)

Well I wouldn't go too large unless the new filter has a flow control. 
and yes running both filters would work fine.


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## bmoore09 (Nov 20, 2010)

KG4mxv said:


> Well I wouldn't go too large unless the new filter has a flow control.
> and yes running both filters would work fine.


Thanks..but eventually I want to NOT use the old one. I need to know the best strategy for getting rid of the old one and just use the new one.


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## KG4mxv (Oct 25, 2011)

Sorry I wasn't clear your plan of running both filers is good for a few weeks then getting rid of the old one.


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## beaslbob (May 29, 2009)

Sorry I can't help. I don't use mechanical filters, just live plants.

Sorry


my .02


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## Mikolas (Jan 16, 2010)

Get an AquaClear 50 or maybe a 70 if your fish can handle the flow. Get the sponge media from the old filter, put it inside the fish tank and leave it there, get the bio-crystals from the old filter and put it in the AC50 (it should have space to put it in). Leave the sponge inside the tank for a few weeks, and then take it out, you should be fine.


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## bmoore09 (Nov 20, 2010)

Mikolas said:


> Get an AquaClear 50 or maybe a 70 if your fish can handle the flow. Get the sponge media from the old filter, put it inside the fish tank and leave it there, get the bio-crystals from the old filter and put it in the AC50 (it should have space to put it in). Leave the sponge inside the tank for a few weeks, and then take it out, you should be fine.


So no need to run both filters at first?


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