Ok just tested my tap water its got 0.25ppm amonia. exactly the same as my tank for nitrite inbetween 0 and 0.25ppm closer to 0 though and a little colouration towards 5ppm for nitrate but closer to 0You also might want to test your tap water. If the tank is cycled and established you should not show nitrite and ammonia. It's possible that you already have some in your tap and that's why with water changes you still are not seeing a difference
Ok i am goin to continue water water changes daily at 30% to help combate the amonia and ive just purchased 2kg of matrix to help aswell and 2 more locks of java fern to put into the tank to help abit with nitriteNitrates are the least harmful of the 3. So I would focus on the ammonia and nitrites. People have nitrates in the 80+ range(not recommemded) and their fish are fine. Ammonia and nitrites can be deadly in even in the smallest quantities.
Yup, sounds like a case of CTSS....crappy test strip syndrome! I'd be sure to buy an API freshwater master kit while at the lfsSomething is not adding up here. With that bioload in over 180 gals of water, and what sounds like sufficient bio media, I wouldn't think ammonia and nitrites would be an issue. Will be interesting to see what you lfs tests your water at. I would also take a tap water sample with you and have them test that too. If you they test positive for ammonia in your tap, you might want to inquire with your water company to see if they have an ammonia source.