i have about 30 saulosi mbuna in a 125g species only tank. My parameters are ph 8.0, gh 12, kh 10, temp 78 Fahrenheit, ammonia 0, nitrite 0, nitrate never over 40ppm. I do 2 50% water changes every week. Yesterday out of nowhere one of my male saulosi was twirling like a perfectly thrown football. He then began swimming normally. He ate very aggressively off top of water as he always does. Today when the light first came on he was swimming tilted to one side a little bit. then he ate normally and is swimming normally again. All the other mbuna are all swimming normally with no signs of twirling. Has anyone had any experience with this strange behavior? Should i do anything or just wait and see? Thanks for any feedback