Heating costs terrible cannot properly over-winter

When we asked about heating costs for our Endless Pool they were evasive We realised that meant the costs were probably going to be high but the actual cost is much much worse than we ever imagined - and that was in the summer Now it is winter turns out that whoever mentioned draining it down for the winter was mistaken that is not recommended Instead all we can do is turn it down to the minimum temperature which is 15 degrees C I cannot understand why it needs to be that warm it wouldn t freeze at 10 degrees less than that It is costing us a fortune when we aren t even using it I feel we were misled by omission I don t think this is suitable for purpose in this country I would not recommend this company or the Endless Pool