Vinegar in a Hot Tub?

[angelique]

Can you use vinegar in a hot tub to balance the PH? If so, how much can you use and does it hurt the hot tub?

[Will]

This website dedicated to hot tub maintenance seems to be ok with it:

Scaling. The white, gray and sometimes brown crust that lives on the waterline of the tub, much like a glass of tap water that has sat for a few days. Vinegar is a good idea except it will change the pH of the hot tub. So, the best thing to do is drain the hot tub half a foot and use a sponge, scrub away and catch the run off with a towel.

According to this website about kitchens and bathrooms, vinegar is an acceptable cleaner for porcelain tubs:

Porcelain sinks and tubs. Cleaning hard water scum: Scour the area thoroughly with a solution made of equal parts of vinegar and warm water using a nylon scouring pad.

From How Stuff Works:

Bathtubs
A bathtub ring requires a strong solvent. Try soaking paper towels with undiluted vinegar and placing them on the ring. Let the towels dry out, then spray with vinegar and scrub with a sponge.
Once a year, dump 1 gallon vinegar into your hot tub, and run it. This will help keep the jets from clogging with soap residue.

Spa Solutions seem to be ok with it too:

Adjust PH first: before putting All Natural Spa Magic into the hot tub water, adjust PH first. Check the PH of your tap water; you then know where you are starting from. Adjust the water PH a little at a time; keep checking it as you go until you get the PH between 8.0 and 8.4. To increase PH use baking soda; to decrease PH use apple vinegar

I hope this helps!