For new wooden tubs

The water will slowly turn brown as the wood cures and "teas" into the water.
This is not harmful and is fine to soak in. 
If you wish to reduce this effect, you can put in two pounds of soda ash and run it for 48 hours with
the filter cycles on.  Drain and refil.   It may need to be repeated as necessary.

Do not use Bromine in a wood tub.  It is too strong for wood, and will cause the wood to burn.
Do not use Liquid chlorine or chlorine tablets (tri-chor) for the same reason.  If the wood has hair like feathering, that is a sign of too much chlorine burning the wood.


With a new tub the filters get clogged from the "tea".   This tea contains resins from the wood that need to be soaked in a
cleaning solution.  I recommend soaking overnight in a solution of Cascade.  One cup in five gallons of warm water (not hot).

Rinse well and rotate filters often (about once a week) for the first month.  That is why it is good to have a spare clean filter ready to go.

You can order new filters on line.