Ammonia stalled?

[STE.vicious]

Posted a thread about a week ago but didn't really get much of a response. So thought I would try my luck again.

I've now had my tank (125lt) cycling for almost 5 weeks (with 10kg of live rock), nitrite and nitrate spiked (2 weeks ago)and came down to 0 and 10. My ammonia though started at 0.5 and basically stayed there, I got a chromis just over a week ago and had done various 25% water changes. Last Thursday my ammonia tested at 0.25, I tested today and it is still 0.25, any idea why the ammonia will not go down? I assume the tank did cycle because my nitrites and nitrates spiked. Any advice would be great!

 

[Fishfrye]

If it came down from .5 to .25 then your tank is probably nearing the end of its cycle. Just remember end of cycle only means that your tank has built up enough beneficial bacteria to handle the ammonia load that was there at the beginning of the cycle. So adding a fish increases your ammonia load to a new level. Your tank will adjust but it takes time. The fish you added is hardy so hopefully he will make it. Give your system another 5 days, do a water change and retest. Dont add anything else until you are reading zero ammonia. Keep doing water changes every other day or so until your nitrites come down too. Add your fish slowly to give your system enough time to adjust to the bioload and you should be fine. Remember only bad things happen quickly in a saltwater tank, the good takes time and patience.