Answer: There are many types of stains. I will go over a few of the common stains. Light Brown/Yellow stain - This is an iron stain. Iron is present in all water and over time falls out of solution and causes these stains. (We offer a stain treatment for iron stains in the early spring) Please call for details.

Green/Grey stain - This is a copper stain. These are not that common but they do happen. Copper is usually introduced into the water from an old heater that is still plumbed into the filter system, or old underground copper plumbing if your pool was built before 1980. The only way to remove these stains is to drain the pool and do an acid wash.

Dark rust colored mark about the size of a silver dollar or slightly bigger - This is a rebar stain. The metal rebar used in the pools construction is starting to rust through to the plaster. Not a serious issue and is really only an eye sore but the pool usually has to be resurfaced to permanently fix the problem.

Small dark spots about the size of a quarter - These are usually caused from something falling into the pool and sitting on the bottom. Pecans, crape myrtle blooms and anything made of metal will cause these stains. Pecan and crape myrtle stains will fade and usually disappear in a few weeks. Metal rust stains will require an abrasive stone to be used to remove the stains. These stones can be found at any pool store.

Fertilizer stains - Fertilizer contains a lot of iron. Be very careful when fertilizing your lawn around the pool. These stains will appear as small little rust freckles on the bottom. Once they appear you must use an abrasive stone to remove them. There may be so many that you will need to drain the pool and do a mild acid wash to remove all of them.

Green Algae that doesn’t seem to brush off - This is an organic stain that usually happens on old rough plaster. If you notice this then call our office and we will have your service tech sprinkle granular chlorine on the area. Granular chlorine has a very high pH like bleach and will make the green stains disappear.

Why was the service tech only in our backyard for 30 seconds?
Why do I have algae on my walls and steps?
Why is my spa green?
What's the white powder at the bottom of my pool?
How long before I can go swimming?
How long should I be running my filter?
Why are my eyes irritated and red?
Is my pool safe if my child has an accident?
Why did my pool turn green/brown after hard rain?
Can you still service the pool if I put a cover on it?
Can I add algaecide to my pool?
What kind of filter do I have and how do I use it?