Ammonia Meter Acting Up?

[danifacetastic]

I've had my new tank for a little over a week now. I have the ammonia reader thing that stays in your tank all the time. It hadn't shown ammonia by Friday so I did a 50 percent water change anyway. Now today, on Monday, it went from Safe (2 percent) to Alert (5 percent). What gives? What should I do?

[chavist93]

Remove it from the tank. Trash it. Buy a liquid test kit.