I set up my 10g in late October with 4 glo danios I did a fishy cycle since I don't know how to do a fishless cycle. I kept up with all the tests using api drops did wc's of about 25% daily as needed .As of February mid month the tank tested as if it was cycled I had 0 ammonia 0 nitrite and 5 nitrate. Since I thought the tank was fully cycled I planned to remove the three danios that made it throught the cycle without issue and put them in my main tank and start quarantining some cories. I bought 5 4 pandas and 1 that looks like a Juli. 2 weeks ago I tested the water and got an ammonia spike abut 0.5 I thought maybe I was overfeeding so have been feeding every other day instead of daily. Sadly I lost one panda corie the others are doing fine. I did a wc about 25% and the ammonia went back down to 0 but this morning when I did my scheduled wc and checked for ammonia again another spike closer to 1.0. I am planning to do another wc later tonight but I don't know what is going on. I tested the tank water and nitrate still shows at 5.0 so why am I getting ammonia readings? So frustrated I thought after almost 3 mos of cycling with the readings I got that the tank was fully cycled could this be a mini cycle I don't know so frustrated. Any advice is appreciated.