unknown fish death

Sadly my yasha goby died this morning and I am very curious to why it happened, it was eating enough to where I though his stomach was full but I could never tell because of how small it is, all I can say is that it was not starved, he was never aggressive when eating so I had to put it in front...

Hello all! It’s a sad morning for me as I woke up to my first fish casualty. My hopes for this post is to get any advice as to what may have happened so that I can prevent it in the future. It’s a bit of a long story but I’ll try to be concise. My royal gramma was the first fish in my tank...