Thank you all for your comments, and yes that is water, there are large and small fish up to 2' creating ripples and a constant dripping of condensation from the ceiling. It all tends to flatten with the 30 sec. exposure.
I'ts very dark in there, the there are red lights at the bottom of the columns, white lights from the walkways in the deep upper right part of the frame, and the only light straight down the row of columns to the left of the frame is only the spotlight at the walkway. I took 12 shots bracketing the exposures, this was the 9th and scanned with only a touch of levels needed.
I just googled this place , unbelievable that it dates back to roman empire time and this was posted at the same moment I posted the work from Rome ...weird ...amazing history to this place