Do I need to clean the pipework in my spa?

Yes, it is necessary to clean the pipework on a spa to do this add a pipework cleaner to the spa and leave it running for an hour then drain the spa and refill it with fresh water. This should be done every 2-3 months. 

Can I use anything to clean the sides of my spa?

No, only specific spa chemicals should be used, as others can have a reaction to the spa chemicals and damage the spa shell. 

 Do I need to drain my spa and why?

Yes, you should drain and refill your spa every three months, because a small body of water will can quickly become contaminated with bacteria, from such things as suntan creams, fake tan and sweat. So a refill of fresh water is needed.