I am looking at specific solar hot water system and had a sales rep say that hard water is not an issue for 2 reasons. He said the liner of the storage tank is stainless steel so it won't rust through. That makes sense if it's drained reguarly. He also said that because they storage tank doesn't "Boil" the water, it won't scale. ??????????? That statement seemed odd to me and I wasn't sure if it was legitimate. Anyone got any feedback on that? We have VERY hard water here and I would love to avoid a water softener for my customers.