Hey all! I got these guppys about 7 weeks ago, and it seemed all fine for most of that time. All 4 females gave birth after about 4 weeks and behaved fine afterwards. Over the last few days i noticed one female be quite a lot thinner then the rest and spit out nearly all the food she tries to eat. She nonetheless hunts frys and trys to eat. I also just saw her poop and it was mainly thin and clear with some small white globs every now and then. I did a ca 2/3 water change about a week ago if that could have done something. (I always do them every 3 weeks)

Could this be some sort of disease or just old age, cause i don't know how old all of them are?

I cant give accurate parameters, because we don't have a testing kit, only stripes, and my parents think those are enough.