ammonia is back

[PlatyGirl76]

:help: On the first day my aquarium finished cycling I added three cherry barbs. A few days passed and I added 6 bloodfin tetras and 4 peppered cory cats. Everything was going fine until I did a water change to lower the nitrate. I tested for ammonia to see if it was still zero as it had been before the water change and to my surprise it was .25ppm. I thought by doing a fishless cycle that the amount of BB produced would be able to handle any amount of waste produced by the fish.

What is happening to my cycle if my ammonia is coming back and when will it go back to 0ppm? Did this happen because of the last 10 fish I added? Is there something I can use to help with the ammonia until the BB catches up with the bioload of the fish. Nitrite is 0ppm and nitrate is 10ppm.

[Goes to 11!]

Did this happen because of the last 10 fish I added? Is there something I can use to help with the ammonia until the BB catches up with the bioload of the fish.
To address you comment about the fishless cycle being able to handle any load of fish waste & your first question:
No, You obviously exceeded the capacity of your current bacteria. 10 fish is obviously a lot to add all at once as you are discovering.

To your second question: Water changes, You will have to do them as required [Possibly daily] until you BB capacity catches up to your bio-load. WC - Test, Repeat as required.

[Sursion]

You added quite a lot of fish in a relatively short amount of time. You're just getting the standard ammonia spike. I wouldn't worry about it.

Fishless cycle does not mean that you will automatically never see ammonia again. If you grow enough bacteria for .25ppm worth of fish, and then you add .45ppm worth of fish, you're filter won't handle it, and it will take a while before the bacteria catches up with the new rate. Same as when you have too much, except in that case the excess bacteria will simply die and leave you with the perfect amount.

I don't know anything about your cycle, but 13 fish within a week will cause an ammonia spike.

[TypeYourTextHere]

I am soon to have this problem as well platygirl since i just added 6 neon tetras and two more dalmatian mollies to my tank. A slight amount of ammonia should not kill your fish, but they wont be very happy about it.

[Honey Badger 1]

when you finished the fishless cycle you added three tiny fish, then waited a few days. during this time the bacteria that you grew during the fishless cycle adjusted to the size of the current bioload in the tank. meaning some of them died off. you then more than tripled the bioload with 6 bloodfins and 4 corys. if you had added them all at the time you finished the cycle it might have been ok since you did a fishless cycle. since you waited several days, now you are dealing with a minicycle.
keep testing for ammonia, nitrite, and nitrate. do water changes when needed. the good thing is minicycles are just that, they don't usually take that long.
i don't know how large your tank is or what volume of water it holds, but in the future, if you have room, add fish slowly, only a few at a time.

[Lady Hobbs]

Right on mommy1.!!!!!!!!! Just as I was about to write but you did it better.

[imma24]

I know how eager most of us are to add fish to our tanks (especially if we're new to this). However, as everyone above explained, you need to give your filter time to adjust. Everyone here has their limits as to how many fish to add at a time and then give your tank a week or two to adjust to the increase in ammonia/waste being produced by the fish - all along, testing your water and doing water changes as needed to reduce nitrates or remove ammonia if it builds up.