What could cause a ammonia and nitrite spike?

My Ammonia is 0.4 and my Nitrites are also 0.4. What could cause this? Tank has been up for two years.

 

Do you have any live stock missing?

 

Is all live stock accounted for??? something could be dead in the tank

 

I had a rusty angel die about two days ago. I saw it in the morning when I got up but got it out right away. Everything else is there. I have two mushrooms that have shrunk up but they don't look dead just bad shape. Not sure what to do. Need help fast don't want to lose everything.

 

Do some water changes..

 

Do you think that would help, or just mask the problem?

 

Have you added anything lately? Like LR? or even stur up the sand bed?

 

Ok it's a 90 gallon tank and I just did a 15 gallon water change. Hope this helps. I'll check water perameters in the morning. Thanks for your help.

 

I vac the crushed coral bed when I do water changes. I did add some new rock about a month ago.

 

I moved up from a 55 gallon to a 90 about a month ago. I saved all the water, crushed coral, live rock,everything. It was then that I added a few new pieces of live rock. I had to add one more bag of crushed coral too. But everything seemed fine till now. I have a few corals and an anenome. All seem to look good for now anyhow.