Algae or Stains in my gunite pool

[rwkelleyjr]

I have a 2 year old Gunite and Salt water pool. Here in Orlando, Fl - the pool is open all year. Regrettably, I haven't been the best pool keeper. But I am attacking with full force now.

Recently got the ph to 7.4 -- down from 8.0.

I have what appears to be some yellow staining on walls and edges of stairs in the pool.

How can I tell if this is a metal problem or an algae stain?

Thanks:confused:

[ds_girl]

I have exactly the same problem. I had some staining when I inherited the pool with a new house. I got a lot more last year when I switched to Baquacil. I learned too late that a metal problem may occur with Bacquacil, and I'm assuming it is metal, but I don't know. The gunite seems pitted at the stain, as it is rough to the touch. I don't have a test kit yet, so can't give numbers. I did have an algae problem, which has cleared up with Bleach treatment. Now I only have the yellow stains, and a few rust marks left from nails I found in the pool when I bought the house.

Any help in removing either would be greatly appreciated.

Thanks!

[derrikm]

Now I only have the yellow stains, and a few rust marks left from nails I found in the pool when I bought the house.

Any help in removing either would be greatly appreciated.

Thanks!

Rust stains from nails? Boy that sounds familiar. I have the same thing and can't figue out how to get rid of them short of using a pumace stone on them, which I don't want to do. Can anybody help with this?

[waterbear]

put some vitamin c tablets into an old sock and hold them on the stains. If they are rust they will dissappear. If this is the case and the stains are widespread you can treat the pool with ascorbic acid (1 lb per 10000 gal.) and a sequesterant (according to label directions) to keep them from reoccuring. If you have spot staining then just use the vitamin c in a sock to remove them and add sequesterant to your water. It is best to do this when the pH is about 7.2 (7.0 for fiberglass and plaster pools).
run the filter for about 24 hours and then bring your TA backi in line if it dropped. Then adjust your pH if it dropped but keep it about 7.4. You might find that your FC levels have dropped also. Bring them up about 1 ppm/day until they are in normal range. DO NOT SHOCK THE POOL FOR ABOUT 2 WEEKS.

If the vitamin C does not remove the stains then they are not caused by iron. To see if they are caused by algae put a trichor tab in a sock and use your pool pole to hold it on the stain for about 15 minutes. If the stain is organic it will bleach. If so then you can spot treat with the trichor and brush, brush, brush!