This week I got a new BTA for my 90g tank, my two clarkii clowns had been bashing the crud out of my smaller existing BTA. I acclimated and placed the new one in the tank on Tues and have been watching it move a bit to figure out where it wanted to be. Yesterday evening when I got home from work it looked great and had extended out in about a 10" circle. When I came downstairs a few hours later I noticed that the water in the tank was extremely cloudy. At first I thought it was micro-bubbles, but close examination showed it wasn't. I was able to trash a jet of cloudiness coming from the new BTA, apparently from its foot (though I think it only appeared that way since it was hanging upside down and was behind a rock). I'm currently QT'ing all of my fish in a different tank for Ich treatment, which left just the three as-yet-uncaught fish in the 90. They didn't seem disturbed at all by the cloudiness. It took me a few minutes to realize that it was most likely spawning, so did a quick google and found some video of other btas spawning and it looked the same.
I added some carbon and put on a new filter sock and left it for the night. As of this morning the water is clear and the BTA seemed to be okay. I'm hoping everything is open wide when I get home tonight.
Anyway, just thought I'd share so that anyone who sees this in the future with their BTA might avoid the initial freak out I had.