Cycling with an established filter - yet ammonia won't go down. Am I being too impatient?

hazyvonne

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Hey everyone! I have 2 established tanks - a 55g, and a 20g. Recently I saw a good deal on a 10g kit, and well, you know how it is - what's one more tank? 😁

My 20g has been running two filters for about 9 months - a 10g HOB filter and a 20g HOB filter. So as I was setting up my new 10g tank, I took the established filter media cartridge out of the old 10g HOB filter and put it in the new one (and the new filter media cartridge in the old filter). I also had some extra sponge hanging around in my 55g, and I put that in the new tank as well (right beneath the filter). Then I took the intake sponge from my 55g tank and squeezed all that brown sludge into the new 10g tank as well. This is going to be my new quarantine/hospital tank, so I put no substrate in, only some plastic plants and two pieces of driftwood (also taken from my established tanks). Water temp right now is about 82.5 degrees. When I filled the tank, I used 50% water from my 55g and the rest fresh, conditioned water. I then added ammonia up to around 3ppm. It's been 8 days, and the ammonia has not gone down. Nitrites are zero. PH is between 7 and 8. I thought that by using the old, established filter, it would basically be almost instantly cycled? Was I wrong? Since it's a hospital tank, I thought that's what I would do if ever needed? Just pop an old filter in and have it ready to go for emergencies? Does anybody have experience with this? Thank you!

to make it easier to read, here's a summary of what's in the new tank
. new 10g HOB filter with old filter media cartridge
. old sponge from the 55g under filter
. intake filter squeezings from the 55g
. 2 pieces of driftwood from established tanks
. 50% water from the 55g
. water temp at 82.2
. ph between 7 and 8
 

Essjay

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Does the donor tank have live plants? If it does there won't be many bacteria in the filter media.
A couple of years ago I set up my quarantine tank with media from my main, planted tank. I added ammonia to check the QT was OK to add fish, and ended up doing a 7 week fishless cycle. Plants take up ammonia faster than the bacteria leaving little for the bacteria to use, so they only grow a few in the background.

The bacteria also spread out in a tank after the initial cycling period with many being in the substrate rather than the filter media.



Edit to add - next time I wanted to quarantine fish, I used some floating plants from the main tank and also bought a couple of bunches of elodea (anacharis) which were left floating. I checked every day and never saw a trace of ammonia or nitrite.
 
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hazyvonne

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Thank you for your replies! Yes, all other tanks are heavily planted. I constantly have extra anacharis (they grow soooooo fast) so I might just chuck some in the new tank to help with the ammonia. Well, I learned something and will try and be patient :)
 

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