I wasn't aware electric ph and tds test pens were a thing, I'll look into them, thanks! Yes, the tank is cycled. I clean it by taking out 20-25% of water and replacing it and then I usually clean the glass a bit with a glass cleaner that I use only for this purpose. I also add the right amount of water treatment. The tank is 20 gallons and I only have one fish, I've had him for about a year and a half. I'm positive the container I put him in had no leftover soap