We have a hot tub in the UK and they are relatively easy to run, but can be expensive. Some pointers for you:
- The manufacturers generally recommend the water is changed every 6- 8 weeks depending on usage.
- The filters need changing on a weekly basis (buy two and rotate them).
- Chemicals need to be kept up (chlorine/ bromine daily). Too much can cause burns, too little and germs are not kept at bay.
- Other water parameters such as pH, water hardness and alkalinity.
- Water clarifiers ans particle removers need using.
In the UK environment, electricity is about £1- £2 per week to run once warmed and stabilised, then you have the chemicals on top. Keeping the water clean will be the biggest headache, I speak from experience . It is best for people entering the hot tub to have had a shower beforehand. On holiday though, you will probably find that they get in all sweaty and with traces of sun tan lotion on or even make up. Once that gets into the water column, next morning the water will be very cloudy and yucky looking. You can then try throwing chemical water clarifiers at it in the hope it returns to a crystal clear water, or refill it!! Also, you need to make sure that when people get in, the soles of their feet are clean otherwise the grit and stuff sits on the bottom unless you have someone in to maintain it on a regular basis. If they sit in the spa while drinking, it can be spilt in the water. 1 bottle of red wine wasn't noticeable while the chlorine was present except for a burgundy red scum around the water line. Next day once the chlorine had been used there was a red tinge to the water. Same with beer (only a different colour)!! Then you could have the people that over indulge (very easy to do in a hot tub because of the heat and water movement), can't stand up and throw up in the water meaning it has to be refilled again.
If it is to be used by yourself and friends when you are there, go for it, they are good fun. If it is to be used for rentals, I would re- consider. You will have to leave caustic and dangerous chemicals in the property, what happens if the customer's kids get hold of it and drink/ eat it? You have no control what people do in it/ with it.
Just a few thoughts.
Mark