by Rob Cox, May 16, 2011
Help! My Swimming Pool is a green algae pool!
Algae Pool ~ This time of year the complaint is common for pools left untended or sitting all winter. Even with a good winter pool cover, pools with insufficient algaecide levels or with high debris loads can allow algae to bloom easily.
Algae is always in your pool, or trapped in your filter, at a micro-level. Keeping it suppressed with good water chemistry, coupled with circulation and filtration.
Following are some tips you can use to fight the Algae Pool and restore your green pool to clean and clear pool water.
1. Clean the Pool: Using leaf rakes on a pool pole, drag the bottom and surface until all of the debris is removed. Lowering the pool water level may make this task easier. Getting rid of the floating and sunk debris is extremely important, as this organic debris consumes the chemicals you are using to kill algae, and also harbors algae itself. Furthermore, it can provide a food source for the algae to thrive in your pool.
2. Consider Draining a portion of the pool water: and replacing with fresh water. If your pool looks like the pool in the picture above, very dark green - drain a portion of the water using the filter pump, a small submersible pump, or set up a siphon if you have a hill nearby. Never drain more than half of the pool without safe pool draining techniques. If you have a small filter/pump on your pool, and wish to keep chemical costs low - the cost of replacing the water can work out in your favor.
3. Lower your pH: Algae likes a high pH, and has trouble with lower pH. In addition, chlorine works most effectively - or has the most efficacy, at lower pH levels. Before shocking the pool to remove pool algae, adjust your pH using a good quality test strip or pool test kit. Add pH decreaser, as needed, to lower your pH into the range of 7.2
4. Shock the Pool: Use any of the available granular for plastered pools, but for vinyl lined pools, use only fast dissolving shock made specifically for vinyl liners. The use of a chlorine accelerator, like Yellow Out is indicated in algae pools with a deeper green color. Using a chlorine booster product will dramatically increase the efficacy of your shock treatment. Follow the instructions on your shock on how much to add to your pool, but generally speaking, it's around 1lb per 10,000 gallons for superchlorinating. For deep green algae pools, however, this amount may be doubled or tripled. Be careful not to mix different types or brands of shock chlorine together in the same bucket, but different types can be added to the pool separately. Shock your pool until a blue/gray color occurs.
5. Filter your Pool: Non-Stop until water clears. Keep an eye on the need for backwashing. If your filter is struggling, using a clarifier chemical can help to coagulate suspended particles. If the filter is having trouble keeping up with the demand, and the water is blue/gray, but not clearing after 4-7 days, consider the filter media. Sand and Filter Cartridges need to be replaced every so often, so now may be the time!