Thanks everyone! Might have to do something as other CO2 diffuser might be playing up and need to trace cords back.
Somehow started early on water change and finished late (like 2hrs just went). Fiddled around with another spot for the buce, I think I'll give up. The catfish pushed it out of the nice cranny I found for it, so I've tied it back on with fishing line to the rock and glued it this time in another spot. Hoping it stays, poor thing never knows what direction it should grow in week by week.
The other one is still in same spot ok.