How long to establish a new power filter?

[sdrone]

I moved a 20 gallon aquarium last weekend. I kept the existing power filter and a few of the plastic plants, etc. I replaced the gravel with sand, and covered that with existing water from the aquarium.

The aquarium is 95% new water. Test results show ammonia at 0.25 and IIRC nitrites at 40ppm.

I've added a 2nd filter, an Aquaclear 30. So I'm running 2 filters now, with the idea that eventually I'd get rid of the original powerfilter.

How long should it take to establish bacteria, etc. in the new filter? 2 weeks? a month?

 

[meegosh]

I would say a month just to be safe. There is no harm in running two filters so the longer the better.

 

[Andrewz00]

when i converted from a HOB to a canister... i left the media from the established HOB filter in a nylon bag in the back of the tank for almost a month.... didnt notice anything negative. again, longer wouldnt hurt...

 

[Floyd R Turbo]

The water from the existing aquarium doesn't transfer bacteria, unless it was siphoned from the gravel. The bacteria live on surfaces. I'm guessing your 40ppm reading was NitrAtes, because NitrItes measure 4-5 ppm on the extremely high side. Your tank is probably cycling, or mini-cycling, since you kept the existing filter (and media too?). Are there fish in it?

 

[sdrone]

I kept existing filter and media. I kept 4 small panty-hose-bags of gravel from the old tank in addition to plants and a piece of driftwood; they're sitting at the back of the tank. I ended up not using water from the gravel; it was freaking black. I covered the sand with tank water from the old tank.

I may not wait until this weekend to do a vacuum/water change. Food etc. is shaking off the old plants and driftwood and collecting on the sand.

 

[BigJim]

+1 for a month's time. Better safe than sorry. I seeded a cartridge for a 5g in my 29g filter for a month and had no problems when I switched cartridges in the 5g.