Pam,
I work for a chemical distribution company with a service dept. for spa repairs and the like. When we come across this, what we need to do is super chlorinate the spa for 24-48 hours.
Using a granular chlorine (dichlor or calcium hypochlorite, or just bleach) raise the level of free chlorine to 10-15 parts per million. Most resedential test kits will not test this high so you might need to purchase test strips. Keep the level this high (it will go down quickly with parasites and algae involved) for at least 24 hours. This will kill the pests and any related waterbourne diseases.
Keep the hot tub running on normal mode for the whole period. This will flush out the system. You may need to do this multiple times depending on the severity of the situation. If you need further help just e-mail me @
[email protected]. There are products that will help, but they are expensive and do essentially the same thing that i am recommending.
If this helped, please take the time to vote positively for me on this site. Thanks,
Adam