Stone Coping - Set in at water level

I am interested in building a pool with a rear wall of stone.

Contractor 1: Tells me that he will build it of stone down into the water level. But, says regular limestone can't be used on the pool (at all) as it will get eaten up (Central Texas Limestone). He insists on using some denser stone shipped in.

Contractor 2: Says that I'll have algae problems if I set the stone down that low. But, that using limestone above the waterline is no problem.

Any recommendations from folks with rock features?

Thanks in advance.

I have no rock features but I would tend to believe them both. Limestone is sure soft and possibly susceptible to damage from pool chemicals.....sounds like he's had some experience.

Algae loves nooks and crannies. That's the toughest spot to get rid of it thereby making it easy to get to the rest of your pool.

Like anything else, these obstacles can be overcome if you're willing to pay a price (maybe not in money but in maintenance time) but it sounds like both these guys could be onto something. I'd proceed with my eyes wide open.:) :)

Dave S.