Re-occuring brown stains in saltwater, gunite pool

[tlcstlcs]

Problem started 2 years ago when heavy rains forced mulch into our pool. Brown stains appeared throughout the pool. The pool contractor was able to remove them, but they continue to come back. He uses Jack's Magic to remove and although it initially works, the stains come back. He says there is nothing else he can do to permanently remove them. Any suggestions on what I can do next?

 

[JohnT]

Welcome to TFP.

I'd suggest you have your water tested for metals to see if that is the source. Most Jack's products are metal removers.

 

[JasonLion]

Brown stains are almost always iron. When you remove the stain from the pool surface the iron goes back into the water. From there it can easily cause staining again if you don't use sequestrant. Sequestrant binds to the metals and holds them in solution, preventing them from forming stains. However, sequestrant breaks down slowly, so you need to be adding more sequestrant regularly (typically weekly). Staining is more likely to re-occur at high PH levels.

Jack's makes several different products, a couple of kinds of sequestrant (which will also remove stains to some extent), stain remover (which gets the metals off the surface and back into the water), and assorted other things.

 

[tlcstlcs]

Thank you! I will have my water analyzed and I will check into whether the pool company has been using sequestrants. If we keep up with adding the sequestrants weekly, do I have a good chance of the stains not reappearing?

Also, we have emptied and refilled the pool with fresh water since the mulch was cleaned out of the pool, so should I still have the metal in the water?