tank hasnt cycled at 8 weeks

Question
New to this. After 8 weeks my levels in the tank are below 6.0 ph, ammonia .5 to 1(can't really tell which shade of green it is#, nitrites and nitrates 0. Water from my tap has ph of 7.6 and no ammonia. Don't understand why the ph is so low. Went to pet store around the 3rd week and he gave me nite out and ph tester. Not sure if that affected the cycling process. All fish have died except 1 platy. She #i think its a girl) seems unaffected through the whole process. I read that you don't want to add any chemical like ph up in it while it's cycling. Week ago with water changed called tetra and they said to use another bottle of safestart??? I was doing water changes 2X week and now i'm back down to once. Not sure what else I can do.

Answer
Hello qt, I will need some feedback from you in order to answer your question fully. What types of gravel and decorations do you have in your tank? I have had a similar thing like this occur at work. Sometimes when you add chemicals to a tank like safestart or prime you can encounter false readings on water tests. How much water have you been taking out of your tank when you do water changes? Also, have you cleaned or replaced the gravel or filters during this time? Your ammonia is not out of control but I am worried about your ph. Your ph is a little on the low side. Do not use any nite out or any chemicals that are supposed to reduce nitrates in the water. Or nitrites for that matter. If you could keep in touch with me over the next few weeks and let me know what the levels are, I could better pinpoint what exactly is wrong with the tank. I worked at a pet store in the past and we are supposed to try and sell as much stuff as possible. With that said, I have never been a huge fan of using large amounts of chemicals in water. They can mess up the cycle sometimes. What I would recommend doing right now is a 50 percent water change. Do not add any chemicals except a dechlorinator. If the water is already without chlorine do the change without adding chemicals. Get back to me with the questions I have asked and I will give you a more in depth answer. Thanks! Jordan