Why is it happening? Can I prevent it?
The mineral content of your water increases every day. This is due to evaporation, which removes only distilled water and leaves the minerals behind. In time, these minerals begin depositing on the walls of the pool, creating pool staining.
Unfortunately, it is not possible to prevent staining completely, but here are some tips to help minimize it:
– Drain your pool periodically to keep the mineral hardness down. If your pool water hardness is high, it will accelerate straining.
– Keep your pool clean! If dirt and debris is left on the plaster it will cause staining. We highly recommend that all swimming pool systems have an automated vacuum connected to the filter system.
POOL STAINING DIAGNOSE
Look at the color of your pool stain to classify the cause. There are various stain colors that commonly appear in pools, and identifying yours will lead you in the right direction for treatment. Depending on the cause of the stain, you will need a unique removal plan.
- The two main stain categories are metal and organic based stains, which come in a variety of colors.
- These color combinations include green-brown, red-blue, blue-green-black, green-brown-red, pinkish-red, or brown-black-purple. Try to distinguish which color combination your stain is.
Watch for organic stains on the floor of your pool. These are likely caused by leaves, berries, algae, worms, dead animals, or other organic debris that will leave stains if allowed to settle on the pool surface. If they are not removed right away, they will sink down and begin to decay on your pool’s floor. Fortunately, organic stains can be easy to remove.
- Organic stains are typically green, brown, or bluish-purple. It may be easy to diagnose organic stains if you can see organic debris like leaves settled at the bottom of your pool floor.
- If an organic stain is suspected, try applying a small amount of chlorine directly to it. An organic stain will dissolve easily with a soft head brush, whereas a metal stain will stay put.
Be on the lookout for inorganic or metal based stains. These substances can inadvertently be introduced into pools from well water or corrosion from copper pipes. It only takes the copper from the size of a penny to be oxidized in your pool and cause major stains. The types of metals that can sneak in your pool includes rust, manganese, iron, and copper. If there are rust colored stains on the pool wall below a ladder, the source is probably a metal, and you should examine the ladder for corrosion too. Check near the stairs, around the drain, and under the lip of the pool for discoloration. Stains that appear reddish brown or very dark are typically related to metals in your pool water.
- The metals that commonly cause pool stains are iron, manganese & copper. Copper is from ionizers and corrosion of copper and brass pipes. This will result in blue, green, teal, black or dark purple stains. Iron is from well water, corrosion of iron pipes and fittings and will result in rusty brown, gray or greenish-brown stains. Manganese is from well water and will result in pink, dark brownish-black or purple stains. Calcium comes from plaster, grout, mortar, or cal-hypo chlorine shock and shows as white crystals.
- If you have a metal based stain, it is important to know exactly which metal is causing you problems in order to properly treat it.
- A common cause of blue-green copper pool stains is improper chemical maintenance. Low pH and high chlorine levels can also erode the copper heat exchanger in a pool heater. Maintaining proper water balance makes it easier to keep metal stains from developing.
Seek out professional assistance. If you want to leave the stain removal to the experts, use your yellow pages to find pool specialists or pool retailers in your area. You will need to take a pool sample to their location so they can test your water and determine exactly what kinds and levels of metals are plaguing your pool. The professional can then recommend a special additive designed to remove your metal stains.
Use test strips to test the water at home. Take a water sample from the middle of your pool. Once you have your water sample, quickly dip one, dry test strips into the water. Without shaking off the excess water, hold it still in the air for about 15 seconds. The strip will then change colors, and you will need to match up the colors of the strip to the back of the bottle to get your readings. There are many different types of test strips you can buy that check for various things, but you really only need to check for pH, alkalinity and free chlorine.
- Use test strips at least once a week. Bring a sample to your local pool store once a month to have it professionally checked, especially when opening and closing your pool.
Try a liquid test kit. There are very advanced liquid test kits, but for a home pool, you can stick with pH and chlorine or phenol red and OTO chlorine test kits. Liquid tests kit can be very accurate but you have to be able to translate the color outcomes well. For example, once you drop the chemicals into your water sample, they are going to change a color, and depending on how bright or dark it is, you have to accurately match it to the directions on the package for a proper treatment plan. Beware, it can be difficult to decipher the different colors and color shades.
- OTO chlorine is the chemical that tests for total chlorine. It’s a yellow liquid you add to your sample. The more yellow, the more chlorine there is in your pool water.
- Phenol red is a red chemical you add to a small sample of water to check the pH balance. The redder the water, the higher the pH balance is.
- With a liquid test kit, it’s hard to see the low end of the colors. Make sure you use a white background to examine the colors to be accurate.
Determine if your fill water is the problem. If you fill your pool from a well, test that water directly before filling your pool. If you determine that there are high amounts of metals in that water, drain your swimming pool to about 1/4 or 1/2 way, and refill it with softened water. You will then need to circulate the water for at least 48 hours and have it re-tested. If there is still a high concentration of metals, repeat the process.
- If your fill water is acceptable, metals are most likely being introduced into your pool water through corrosion. Check all pool equipment for corrosion to make sure they are not leaking metals into your pool water.