Don't think it was 5200
Jeff:I do not think that it was 5200. I have removed mine and it was a SOB, but it came off.I suggest that you get a couple of flat pry bars. Get one started and then get a second one going in the opposite direction. Once you get the seal broken, it will lift.I resealed my tank with Life Caulk and it was the same when I tried to remove the lid the second time. I have recaulked this sucker about 4 times and vowed to never do it again. My final resolve was to have the lid glassed in place. Place two inspection ports in the lid and she should be good to go.Be sure to cut all of the caulking away from the edge all around the tank before you start.