I went into my local petco today to return a yellow cichlid I had purchased a few days earier that for some reason didn't survive the transition. I brought some water to let them test as its required to get your money back. the associate a nice enough older lady tested the water and looks at me and says your ammonia levels are very high above 4ppm and your nitrates are high above 2ppm and she said my nitrates were alarmingly high. I explained to the lady I found that to be very odd because I checked my levels with my master test kit right after I removed the dead fish and all levels were within spec. I asked her if I could get a couple snails and a algea eater to which she denied me because my tank wasn't suitable for life. I chuckled a bit and explained to the lady my other yellow and my upside down cat are doing just fine but she still refused to sell me anything. So I came home retested my ph, ammonia, nitrites, and nitrates, ph 7.6, ammonia 0ppm, nitrites 0ppm, nitrates less than 80ppm I did get my money back so it wasn't a total loss, I just wish they would train the employees how to properly test the water, who knows how many peoples fish they kill with bad info.