Hi,

I opened our pool a few weeks ago. It was a fairly easy open and the water was sparkling clear within a day or two (and still is). However I noticed that after vacuuming and running the dolphin multiple times most of the pool surface still had a light tan/brownish stain. The pool was stain-free when I had closed it last fall.

I have tried multiple tests to determine the next course of action, but am unsure of what to do next. Here is what I have done so far:

1. Added 1/2 Gallon followed by another 1/2 Gallon of a sequestering agent (GLB Sequasol) -- No Change.

2. Brushed, brushed, brushed.... -- No Change.

3. Placed granular clorine in a sock and put underwater on a stained area for 30 minutes -- No Change.

4. Placed PH Down (Sodium Bisulfate) in a sock and and put underwater on a stained area for 30-minutes -- No Change.

5. Tried the ProTeam Metal Magic Test (Sponge soaked in Metal Magic on stained area for 5min, 15min, 30min) -- very very slight change in stain after 30 min.

Other info:

1. I usually top off water throughout the year with well water.

2. My daughers say the pool surface is extremly rough. It has always been very smooth (we brushed endlessly after marcite when we built two years ago).

3. The Pool is a 28,000 gallon gunite with a standard white marcite finish. The spillover spa is a diamondbrite finish. The spa had a similar tan/brown stain on it when opened, but I drained and scrubbed with a mild muratic acid solution (1 part acid, 4 parts water) which seemed to do the trick.

My current numbers:

FC: 1 (was higher earlier, still adjusting the SWG)

CC: 0

TC: 1

Ph: 7.4 (was over 8.0 when I opened)

Alk: 100

Cal: 220

Cya: Unmeasured

I am unsure what to next. It appears that whatever metals were suspended in the water last year precipitated out over the winter. Any help anyone could offer would be greatly appreciated.

Pat.