Installing a pool in the Austin hill country where the only source of water is a large 31K gallon rain water collection tank. Anyone have any experience and/or know of any issues with using rainwater for everything pool related including for mixing with/shooting the gunite, keeping it wet during the curing period, filling the pool, maintaining the water level, etc.? As expected, the rainwater is slightly acidic PH=6.5) with total alkalinity and total hardness both around 50 PPM. Greatly appreciate any advice you can provide...
Using rain water for mixing with cementitious materials is fine.
I don't see significant issues with using to wetting the gunite down prior to plastering.
But I strongly suggest that you do not use it to fill a newly plastered pool. The fill water should have a positive LSI so that no etching occurs while filling.