I have some organic stains in my gunnite pool. Thunderstorms here blew copius amounts of crepe myrtle flowers & seeds in our pool. As a result I have what looks like tobacco stains on the gunnite surface at a depth of 9 feet.

Does anyone have a suggestion for how to clean these stains? I have successfully cleaned some of these stains by scrubbing BioGuard chlorine tablets directly onto the stain.

Help, please? Thanks

Welcome to the forum. dsm,

Chlorine is almost always effective against organic stains. It may take more than amonth in some cases but higher than normal levels of chlorine would be my first attempt to remove anything organic.

After several applications of chlorine (scrub surface with tablet) to affected areas I can reach, I am convinced that chlorine application is the right solution. Now then, how do I approach this on the stains under 9' of water?

Someone here had built a puck holding device to scrub stains with, you'll have to search.

You could get an 8 foot section of pvc and some granular chlorine, pour the chlorine down the pvc over the stain and let the granules settle over the stain and try and brush the following day.

Elevate your chlorine levels about 50% above where they should be and HOLD THEM THERE for at least two weeks. I think you'll see the stains start to diminish. I would hold the FC up for 30 or more days because it's a cheap fix if it works.

Can you post current test results.

Latest update. Prior to reading the suggestions here (thank you) I decided to increase my chlorine by adding 3 more cups of granulated chlorine, and let it settle on the affected, stained areas. I am pleased to report that this morning virtually all of the staining has been removed.

Next thought, is it likely that these stains could have become permanent had I not reacted & pursued a solution as quickly as I did? BTW, the crepe myrtle trees are gone. Any landscape suggestions?

No, the stains would have gone away eventually even if you did nothing, though it might have been a long time.

That is my area of expertise. How close to the house? How close to the pool? I assume you would prefer a smallish evergreen that can withstand the harsh summer as well as winter temperatures there. Or maybe a deciduous tree is acceptable if it grows far enough from the pool and is small enough to not result in too many leaves overall. Choices?

Then there is the question of flowers... as you have discovered, flowers bring with them the problem of what happens as the flowers fall. Dead flowers are bad enough and fruit or nuts can be worse.

Finally, I do not know if your soil is as alkaline as that of Ft Worth, soil there can be harsh and some plants will not tolerate it. Is your soil of concern in that regard?

Thanks anonapersona. In Flower Mound our soil is a little sandy. 30+ years ago this was a peanut farm. I don't have the thick black gooey clay you find in Dallas County.

The crepe myrtles (2) had grown to 25' height with 25' spread, groomed to a tree form. The root balls were planted 8-9' from pool water edge. There was no overhang of tree limbs over the pool.

Your assumptions about plant choice are generally accurate. I have a 1 acre yard so I have lots of room to move further from the pool. One thought might be row stand of Belinda's Dream or CareFree Beuty earth kind roses. I'm open to suggestions and I'd like to replace the landscaping. It added character to the area.

Is this spot seen from the house? Is this before the pool or after, as seen from the house or sitting area? Do you require the shade? What is the general style of the home and landscape? with a yard that big my first thought is to bring in grasses.

My crepe myrtle and wax myrtle seed stains don't last more than about 12 hours just with proper chlorination of the pool water. Any organic stain such as this will disappear over time with chlorine.

I have a crepe myrtle by my pool and had the husband cut it way back in the spring. I hate dipping crepe myrtle flowers out of the pool. Now If I could just get him to cut down the 100 ft. tall pine trees that drop needles in the pool it would be a great thing! LOL!

Back door opens to a 25x23' concrete patio, covered by a pergola. Sit on the patio, look across the pool to an expansive backyard. The crepe myrtle were on the far side of the pool, framing the view of the backyard under the canopy spread of the limbs.

Have been thinking about grasses for a long time, actually. But I also like the diversity & contrast of height in the landscape. Only the dog uses the shade, and not often at that.

One easy substitute for a crepe mrytle is the wax myrtle. It is a fast growing shrub that can quickly reach 12 to 18', rounded, evergreen, is brittle and ice will certainly break limbs. The old fashioned Japanese ligustrum can be trained to a small tree form, I've always found the fragrance of the May blooms to mean the start of swim season to me. If you soil is a bit on the dry side the Texas Mountain Laurel is lovely, if slow growing. If you actually need a tree you can look for the Evergreen elm, Ulmus parvifolia. Bamboo can be lovely, provided you are certain to get a clumping bamboo NOT the running type. Red tip photinia actually makes a gorgeous nearly-tree if you just leave it alone and do not shear it into a cube like everyone seems to need to do. It will have both red tips and white blooms at the same time, I've seen one that was over 20' tall and a perfect oval form. Finally, the native yaupon will eventually have a form similar to the crepe myrtle if you trim it as it grows taller. A japanese black pine is a possiblity if the overall design of the yard will allow that, could be lovely with an attractive bunching of grasses.

If there was situational shade from other buildings or other trees, and you could tolerate the falling leaves, a japanese maple can be lovely, if the sun is not too harsh and it gets water. Very pricey.

I suggest that you visit the Dallas Arboretum and look at the trees and shrubs there to see what things look like at maturity. You may find more inspiration there.