Pool Tool makes zinc anodes to help alleviate the results of electrolysis in salt water swimming pools. This anode is obviously doing it’s job, though it is so corroded and built up with scale that it is time to change it out so it can continue to remove trace voltage from the pool.
The rust stain seen from this light in the photo above alerted us to the issue, where we investigated to find out if this is a salt water pool, and if it had an anode. The next thing we will verify is the water chemistry to make sure that pH, alkalinity and calcium hardness are all in range!
To remove the stain under the light we can add some Natural Chemistry Stain Free to the area, give it a few minutes to work, brush and the stain will be removed. This needs to be followed up with a metal remover such as FerriTabs or SeaKlear Water Clarifier to remove the metal from the water.