Give them a call. They should be able to give you an honest answer
Yes there are tankless heaters that are made just for that purpose. There is two types. One that circulates the water and heats it slowly after the pool is filled. This would resemble a hot tub or spa. The other type would heat the water as the tub was filled, this works well however keeping the water warm then becomes the issue. Unfortunately we only service residential home at this time. That said here is a link to a product that I have worked on in the past. http://www.inyopools.com/Products/07501352011474.htm#parts
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