cycling question

[akg]

I'm starting a 5 gallon tank because I want to move 3 pesky danios (very pretty little glow fish) out of my 10 gallon tank. When I got the 5 gallon tank, I took the Top Fin 10 filter out of the 10 gallon and put it right into the 5 gallon (and got a Top Fin 20 for the 10 gallon.) I also have a goldfish in there (my daughter rescued it from a carnival with the toss of a ping pong ball.) One guy at a LFS said with the filter from the established tank, the new tank should be cycled on the first day, but I thought I should wait a bit before putting the glow fish in there. ("Goldy" is destined for a pond or one of the water lily containers on my patio.)

Here's the thing - the 5 gallon has been set up for a week, which I know isn't long at all, but I never cleaned out that old filter - it was beautifully gunky when I put it in the 5 gallon. Testing shows ammonia at zero, nitrites at zero, but the nitrates are also zero. Something must be eating up the nitrites, so why don't I see evidence of any nitrates? What am I missing??

Thanks in advance for any help!

-akg

[Twistersmom]

Not sure, but if the bacteria does not have ammonia to feed on, it will die off.
So the filter in the 5 gal came off of a cycled tank?
If this filter has not had a source of ammonia for a week, the beneficial bacteria may no longer be there.

[lateinningmagic]

I don't know the technical terms, but as I understand it cycling works something like this:

1. Ammonia is introduced into the tank. Either by dosing when starting a fishless cycle or by the waste of fish
2. Ammonia eating bacteria develops and results in NitrItes being formed
3. Another type of bacteria comes along. This bacteria feeds on NitrItes
4. As the NitrIte feeding bacteria does its thing, it results in NitrAtes

NitrAtes are the least toxic to fish, and either because no bacteria in the aquarium eats it or, no bacteria eats enough (I'm guessing here) of it you should be reading NitrAtes at all times once your tank is established. (Unless you have enough plants to use it?)

Anyway, the LFS guys was right. You tank would have been ready to go the minute you put the filter from the established tank into the your new 5 gallon. The bacteria is mostly if not all gone now that its been starved for a week. Since the the first bacteria has no ammonia to eat, it dies. Since it died, no nitrItes were formed, and the second bacteria died. Since the second bacteria died, no NitrAtes were formed. That is why all your test are reading 0.

[akg]

OK - I'm digesting that information. But I've got a rather large goldfish in there (it must be close to 2 inches long) shouldn't Goldie be producing enough ammonia to keep the biological filter alive?

[yourchoice]

If you filled the tank with new tap which has no nitrates it could take a little while(give it a week) to see nitrates.The cycle should still be alive .

[lateinningmagic]

OK - I'm digesting that information. But I've got a rather large goldfish in there (it must be close to 2 inches long) shouldn't Goldie be producing enough ammonia to keep the biological filter alive?

Missed the part about the Goldfish being in there. You should still have bacteria in there.

[Zaffy]

There is bacteria in the gravel of the goldfish tank, that will stay alive. You'll have a mini cycle while the bacteria population grows to it's previous level.

You also transferred an established bacterial colony to the 5g when you moved the filter (assuming you kept the filter material). You'll also have a mini cycle in that tank. It's possible that the bacteria you added is more than the danios produce, this might give you the results you're seeing, but you should still see Nitrate build up over the next days/weeks.

[akg]

OK - that makes me feel better. I will say that the goldfish wasn't really active or eating the first few days he was in his new digs, but I would have imagined that he was still producing waste. He's now looking much happier and is eating when I feed him. After reading your answers I was worried that he would end up cycling the tank, which wasn't my intention. I just figured a sizeable goldfish could handle the new tank better than 3 small danios. When I start seeing nitrates, I'll move the goldfish to a new home (either a friend's pond or one of my water lily containers) and move the danios in.

Thank you for the info!

[akg]

I know it's still not that long - but I tested the water again yesterday - still no nitrates. There's no ammonia or nitrites - so where are my nitrates?!?!?

[Rbishop]

Are you using a good liquid test kit?