Hello
Hydro Cooling devices dissipate most of the power cunsumption in the cooling water.
So for a 5500W power consumption miner, it will approximatively heating 1 liter of water by 1.3°K per second.

So if you uses it to heat a spa of 1000 liter,  temperature raise of spa will be approximatively of 5°K per hour.   

For permanent use, temperature will stabilise when power loose of spa is equal to power of miner.  Only  a spa will not be enought to cool one hydro miner. You needs at least a swiming pool (or live at the north of alaska in winter...)