So here is a question - how do you seal your waterline tile? I made the mistake of using white limestone for both my waterline tile and my coping. The issue with this is the coping will get brown alkali stains on it every couple of months and the only way to clean it is with muriatic acid - yes I know not good for the limestone, but it is the ONLY solution I have come up with to remove the brown stains. Tiles when from brown to white again with a diluted mixture. The stains come from moisture getting into the limestone from BELOW, making it's way to the top, evaporating, and leaving brown residue on the top of the stone. We are BONE dry here in Houston so I am thinking moisture may be working it's way thru the white limestone water line tile and getting into the ground under the coping. Two concerns - 1. is it ok if the sealer gets into the pool water? 2. If I lower the water to below the waterline tile and seal and the sealer drips down the plaster it will leave 'streak' marks as that part of the plaster will be sealed not letting it get wet (we had this issue during build and they had to use some pretty nasty chemical to get the sealer off the plaster). Thanks!!!!
Any other ideas welcome - I don't mind using diluted muriatic acid to clean the limestone on occasion (not good for the stone), but that is just a band aid. Need to address where moisture is getting to under the coping and the only thing I can think of is the waterline tile being wet 100% of time of leaching some moisture into the ground under the coping. On a side note, the coping tiles above the strainers don't have this issue (because there is no ground beneath them). Thanks!!
Any other ideas welcome - I don't mind using diluted muriatic acid to clean the limestone on occasion (not good for the stone), but that is just a band aid. Need to address where moisture is getting to under the coping and the only thing I can think of is the waterline tile being wet 100% of time of leaching some moisture into the ground under the coping. On a side note, the coping tiles above the strainers don't have this issue (because there is no ground beneath them). Thanks!!