Pool was completed about a year ago. After it was filled, we immediately noticed water leaking from the spillway/spa on the coping on just one side of the spa. It only leaks when the fountain is running and water is coming down the spillway. The pool builder has been out multiple times, chipping away stone, and re-grouting on more than one occasion. Their last position was that it was just a nominal amount of water and this is normal. It doesn't seem to me that such a leak is normal.
Their latest proposal is to drain the water in the spa a bit and apply Hyrdroban to the surface of the stone and grout of the spillway. I have a few questions here:
1. It seems that any sealant placed on a porous stone that has water flowing across it will only last for a limited period of time. I don't want a temporary solution that masks the problem temporarily and then it returns. If this solution would solve the problem, how long should I expect it to last?
2. Will a sealant darken the stone or change the appearance compared to other stone around it?
3. Based on the picture that I attached, is this even the right approach? Is that where the water is coming from?
Any suggestions would be appreciated. I am considering getting a third party involved based on the pool builder's lack of success so far here.


Their latest proposal is to drain the water in the spa a bit and apply Hyrdroban to the surface of the stone and grout of the spillway. I have a few questions here:
1. It seems that any sealant placed on a porous stone that has water flowing across it will only last for a limited period of time. I don't want a temporary solution that masks the problem temporarily and then it returns. If this solution would solve the problem, how long should I expect it to last?
2. Will a sealant darken the stone or change the appearance compared to other stone around it?
3. Based on the picture that I attached, is this even the right approach? Is that where the water is coming from?
Any suggestions would be appreciated. I am considering getting a third party involved based on the pool builder's lack of success so far here.

