Nuclear green Paly Die Off rate

I counted the Poles in the three pics posted here came up with 70ish, 70+ and 60+ so a picture does say much they are thinned and I would give it a few days as the really small polups may look allot different than they do now and the very small ones may look like the small ones there can be some that closed all together and look like part of the mat. As for counting I only counted ones I could see clear enough and yes that meant even the back a skirt. I have only seen this in one thank where there was loss like this and it was due to heat loss and the water quality, so I ask how cool was the water and did you test the water? http://www.flickr.com/photos/48470641@N03/4689889238/ in this picture I only count between 70 and 80 ish polups clearly but you can not see the entire rock in any of the pics. Unfortunately it is buyer be ware as we were shown a picture with the add for sale so I would have counted the polups I could see and ask questions.

Bill