My usually very active guppy, had fry the other day and has not been swimming around as usual. She's using her arm fins for swimming n not really her tail. So she's mostly waddling in the same place. She has changed positions in the tank, like she was up the top in the corner last night. And now she's under some plants down the bottom now. I also put some new fish in on the weekend. Some panda Corys and neon tetras. 3 of the tetras the shop gave me were sick and died almost instantly. The rest seem to be doin fine. I've done a couple over water changes over these few days then because of that.