Q about install of new filter.

[Thanes]

Just a quick question,I put a new canister filter on tank with new media( mostly clay & some sponge.) & have let it run for 4 weeks with the old filter & media still being used,would the new filter media now be ok by itself as in the bacterial side of things?I have given the media 1 rough clean since it was installed.Any thoughts would be appreciated.
Cheers Brian.

[nemo1981]

I would think it would be fine by now.
4 weeks is plenty of time to get a good bacteria growth.

Does the tank have fish?

[GTR73]

Be sure to transfer most of the media from the old filter to the new one if possible.

Bacteria colonies in a tank will grow and decrease according to the biological load, so currently both your filters support that load. If you take one filter away you run the risk of halving the bio filtering capacity for the tank, so to negate this just remove the media from the old one and add to the new one and you should have no problems.

When I replace an old filter I just transfer all the established media from the old to the new filter straight away, and take the old one out immediately. Only difference is I lose a minimal amount of bacteria that coated the plastic surfaces of the old filter but the majority of bacteria is in the actual media. So never had any dramas doing it this way many times over the years. As long as the established bacterial colonies in the old media remain intact doesn't really matter what filter they get transferred to.

[Paul]

why not take all the guess work out and buy a test kit?

[climber05]

a test kit is not gonna tell you if  your filter is cycled or not. eg ammonia might read 0ppm but if there isnt't sufficient ammonia eating bacteria in the tank and you add fish the ammonia level will spike very rapidly bringing you back to the beginning of the cycling process. just add a small amout of fish to begin with and test ammonia every second day for 2 weeks. if everything is cool slowly add more fish. sorry i read the post wrong. i was presuming there was no fish in the tank. ahh well.
cheers
chris

[Thanes]

Thanks for the replies,the only thing I can take out of the old filter & put in the new is some ceramics,the rest wont fit properly.So I'll change some ceramics over & we'll see what happens.The new filter has actually been on for about 6 weeks & the old filter is still clean after last clean(about 3 weeks ago)because the newie is twice as powerful it doesn't get to filter much dirty water anymore.So thanks again I appreciate your opinions.
Cheers Brian.

[waltec]

6 weeks is more than enough to allow the colonisation of bacteria but as previosly mentioned the amount of bacteria is dependant on demand, so because you have been using 2 filters, they will have been distributing the load, and as the new filter is bigger it should have a higher quantity of bacteria.  when you remove the old filter you will actually be removing its bacteria from the total filter system.  The new filter's bacteria will multiply to pick up the shortfall but this takes time.  Just be vigilant of your fishes behavour and mabye do a couple of small water changes over the next week or two...  You are in a much better situation than if the filter was straigt out of the box (it has had a great headstart)

Matt

[GTR73]

Moving over the ceramic is an excellent idea. This is probably where most of your bacteria colonies are living in your old filter, so moving the ceramic should cover you.