I had a terrible time with our first BTA, a green one. It kept moving from the spot I thought was best
Then, I started playing around with the water flow and determined the GBTA liked lower water flow in the spot I'd picked out for it.
When we recently moved the GBTA to another tank, we made sure there was lower water flow for it and the RBTA that also went into the tank. Both have stayed where they were put. HTH
