High Water Parameters

[obx fish]

I did a water change today because my water parameters were high...about 15 gallons out of a 75 gallon tank. This evening I did another water test and these were my readings...
Nitrite 0.8 PH 7.5 Nitrate 20 Ammonia 0.3
Can anyone please give their opinion on why this might be happening??? Thanx
The tank has been up and running since March 2002

 

[bang guy]

Although the Nitrite is harmless at that level the Ammonia should be stressing some of your animals. I hope it's just a bad test kit.
If you test kit is accurate then I imagine either something has died, or you are over feeding or your sand bed isn't live anymore and the detritus has built up past the break point.

 

[nm reef]

First I'd be curious what tests you use and how old they are.
Second I would see if a LFS could run the same tests and compare results.
I agree that your nitrites would be toxic if the test results were accurate. Ammonia is high also for a established system. How are your fish/corals doing...any stress related symptoms?