Tweebdonny,
Your stains are similar to what I was experiencing up until this past monday when the pool company conducted an acid wash to remove my paster stains. Long story short, my pool is approximately 6 months old and during such stains were developing similar in color to yours. I conducted the tri-chlor test and the absorbic acid tests with negative results. I conducted the dry acid test in a sock, which you must be carefull when conducting, and it left a yellow colored streak from the test location to the deep end of the pool. Eventually the warranty dept. for the pool company inspected the stains and determined that the stains were "hydration stains". I was to waite until the winter to see if the stains went away, however, they progressed. So, as stated above my pool was drained and acid washed and the stains are no longer present. My pool is being refilled as we speak because the plaster shell had to remain empty so that the sun and heat could aid in the stain removal. Its been 101 degrees in Houston this week so the drying out of the "hydration stains" should have happened. I will post pics later this date, Im at work as of this post, of what my plaster looked liked when the pool was drained prior to the acid wash so you can see the extent of my problem prior to the acid wash. I hope this helps. :cop:
