So I've had my aquarium set up and running for a few months now, started roughly in August, 2012. The tank is a 55 gallon community tank set at 75F. Until last week, I had four Angelfish and an Opaline Gourami. Up until recently, I thought my aquarium had been fully cycled. Obviously I was wrong.
After introducing 13 Zebra Danios, 4 Corydoras Catfish, 1 Blackghost Knife and 1 Bristlenose Catfish, I've been seeing signs of ammonia. I checked the water with my API test kits. I got an ammonia reading of about .25 ppm, Nitrite at 0 and Nitrates at around 5 ppm. I don't know what the pH is.
Once I discovered my water had signs of Ammonia, I started doing daily to second-daily water changes of about 50%. I then realised that by taking away all the beneficial ammonia to kickstart my Nitrogen Cycle, I may have potentially ruined the Cycle all together. I'm scared to continue doing Partial Water Changes because that might destroy the Cycle, but I'm also scared of leaving the water because the ammonia might kill my fish.
What should I do? Should I continue to do water changes, and risk delaying or consequently kill the Nitrogen Cycle all together, OR should I stop doing water changes to raise the ammonia to kick start the Cycle and let the Cycle take place (consequently risk killing my fish)?
Filtration: Two internal filters 300 Gallons Per Hour and 400 G/PH
Ammonia: .25 ppm
Nitrite: 0 ppm
Nitrate: 5 ppm
Fish: 4 Angelfish, 1 Opaline Gourami, 13 Zebra Danios, 1 Bristlenose Catfish, 4 Cory Catfish and 1 Black Ghost Knife. Amazon Swords and Java Moss present.
Advice would be much appreciated,
EDIT: Sorry, I don't think I posted this in the right area!
You have not harmed anything. You had a cycled tank but may have added the new fish too quickly. Best in the future to add fish you want over a few weeks to let the bacteria catch up.
No need to change water so frequently ...only change when you see ammonia. 50% is too much at one time...keep that kind of change for emergencies. Large water changes can change the parameters of the water too drastically and stress your fish. 0.25 ppm is also not an emergency just a wake up call to more frequent water changes for a while.
The most important bit of information you need though, is that here is very little bacteria in the water. You have not done anything to your cycle unless you are vigorously vacuuming your substrate and cleaning your filter..that is where your bacteria lives. All water changes will do is lower the little ammonia you have, and refresh the water with offers and minerals.
So you did the right thing. Keep testing and changing water. Whenever you see ammonia and your fish will be fine.
Thank you for your help. I've taken your advice into account, hopefully I can start seeing an improvement soon!