If the floor is holding water [puddling],concrete supply companys will have a product of "Glaze n seal" paint and etching sample in black 1/2 pint can.these are free.Read all info. before use.Tape off 12" sq. area very well.apply the jel with stiff nylon brush. let set tell all action of jel has stoped.hose off with water. It will etch.But you still have to address the puddling.An over lay product will take care of that. If all else fails your expections, floor grinding is last costly resort . $2.50 and up per sq. ft. Good luck.
We all no alot but can only do a little,