I suggest the OP uses the Search function and start reading, before asking any more questions.
Regular group 24, 27 and 29/31, while hooked up to a pedestal full time, are a much better bet for their type of usage.
Industrial type batteries are what the small minority, off the grid, with generators, charge controller and solar panel crowd prefer, only because they actually USE the deep cycle function on a daily or pretty regular or majority of the time situation.
For the OP GC-2's were the wrong battery being used in the wrong application.