Green Pool Water

A. I removed my cover and my pool is dirty green.

We suggest the following procedure:

1. You should be able to see the bottom. Remove debris from the pool floor with a large leaf net . Make sure you can see the pool bottom before vacuuming to waste to avoid clogging the lines.

2. Adjust the pH to 7.2 to ensure that the water clears completely.

3. Shock the pool. This means (super) chlorinating the water to kill off any bacteria and algae. If your pool is very dirty, it may need MANY gallons (several 10 L pails) of liquid chlorine (shock) over a period of days before the water clears. Start off by adding 10 Liters (one yellow 3 gallon pail) for above ground and 30 liters (three yellow pails). Continue this process by adding 10 liters ( 3 gallons) at a time until you notice the water changing colour to either cloudy white, light green or clear. YOU CANNOT OVER SHOCK A POOL! The more you add, the quicker it will clear! Note…shock is available in liquid or powdered form, but we recommend against using powdered shock (it works too slow and could compromise the efficacy of the free chlorine). Add a high-quality algaecide such as CLEAN & CLEAR MINERALS from C-Pool Minerals to the water at this point. This will speed up the clearing process and ensure that the algae does not return.

4. Run your sand filter 24 hours a day and backwash daily for the quickest results. Green or cloudy water will quickly clog a filter, therefore you may have to backwash your filter twice daily until the pool clears. Run the backwash cycle for 60 – 90 seconds. The more you run your pool, and the more you backwash the filter, the faster the pool will clear up. If you have a D.E. filter, remember to add a new D.E. to the skimmer closest to your filter after each backwashing. A D.E. filter is more work than a sand filter, but the D.E. filter will clear a green pool about 50% faster than a sand filter. A cartridge filter will need washing several times a day and if it clogs the system will shut down so keep  the cartidge clean and swap with a backup cartidge is you are able.

5. If you follow these instructions and your pool does not clear up within 4 or 5 days, your filter may not be functioning properly. See our blog on POOL FILTERS. The pool will never clear up if the filter is not working properly.

B. My pool was opened OK, can see the bottom in the shallow end, but still has cloudy green water. See the blog, CLOUDY POOL WATER

We suggest the following procedure:

1. Adjust (if necessary) the pH and Alkalinity levels of the water using pH Plus (baking soda), pH Minus (muriatic acid) and (optional) Alkalinity adjustment (should be OK if the pH is normal). These levels must be within the proper ranges or the water may not clear completely.

2. Shock the pool. This means (super) chlorinating the water to kill off any bacteria and algae. If your pool is very dirty, it may need MANY gallons (several 10 L pails) of liquid chlorine (shock) over a period of days before the water clears. Start off by adding 10 Liters (one yellow 3 gallon pail) for above ground and 30 liters (three yellow pails). Continue this process by adding 10 liters ( 3 gallons) at a time until you notice the water changing colour to either cloudy white, light green or clear. YOU CANNOT OVER SHOCK A POOL! The more you add, the quicker it will clear! Note…shock is available in liquid or powdered form, but we recommend against using powdered shock (it works too slow and could compromise the efficacy of the free chlorine). 

3. Add a high-quality algaecide such as CLEAN & CLEAR MINERALS from C-Pool Minerals to the water at this point. This will speed up the clearing process and ensure that the algae does not return. 

4. Run your filter 24 hours a day and backwash 2 times a day for the quickest results. Run the backwash cycle for 60 – 90 seconds. The more you run your pool, and the more you backwash the filter, the faster the pool will clear up. If you have a D.E. filter, remember to add a new D.E. to the skimmer closest to your filter after each backwashing. A D.E. filter is more work than a sand filter, but the D.E. filter will clear a green pool about 50% faster than a sand filter. A cartridge filter will need washing several times a day and if it clogs the system will shut down so keep  the cartidge clean and swap with a backup cartidge is you are able.

5. If you follow these instructions and your pool does not clear up within 4 or 5 days, your filter may not be functioning properly. The pool will never clear up if the filter is not working properly.

C. My pool was clear to start, all parameters OK,  then hot humid weather came and the water turned emerald green.

We suggest the following procedure:

1. Chances are that the CYA levels have spiked if you were using chlorine pucks.

CYA is a stabilizer additive to Triclor chlorine pucks and is released into the water as the puck dissolves. CYA is short for cyanuric acid. In water content concentration of up to 70 parts per million, it helps chlorine effectiveness, but over 70 ppm, the opposite is true. The amount of time to kill bacteria lenghtens as the concentration of CYA increases. The ideal is 40 ppm.

The danger of CYA buildup is loss of efficacy of the free chlorine needed to fight both algae and bacteria. If you are using triclor for disinfection ONLY , and have an algaecide in place, then CYA will build up quickly. If you don’t raise the free chlorine level correspondingly, algae will begin growing. This is also the reason that during the summer a pool starts out with no algae and eventually it has algae. You need more free chlorine. 

Trichlor can be used as a sole chlorine source but you need to keep higher and higher levels of free chlorine as the CYA level goes up.

2. Check all parameters, pH, hardness, CYA, free chlorine etc. are OK. If not, adjust them. 

Shock the pool. This means (super) chlorinating the water to kill off any bacteria and algae and raises the FREE CHLORINE levels. Start off by adding 3 or 4 gallons, and if you see no results overnight, add 3 or 4 more gallons the next day. Continue this process until you notice the water changing colour to cloudy white, light green or clear. YOU CANNOT OVER SHOCK A POOL! The more you add, the quicker it will clear! Note…shock is available in liquid or powdered form, but we recommend against using powdered shock (it works too slow and could compromise the efficacy of the free chlorine). 

3. Add a high-quality algaecide such as CLEAN & CLEAR MINERALS from C-Pool Minerals to the water immediately. If C-Pool is already in the water, double the weekly dosage and broadcast.

4. Run your filter 24 hours a day and backwash 2 times a day for the quickest results. Run the backwash cycle for 60 – 90 seconds. The backwash should be a greenish cloudy colour. The more you run your pool, and the more you backwash the filter, the faster the pool will clear up. If you have a D.E. filter, remember to add a new D.E. to the skimmer closest to your filter after each backwashing. A D.E. filter is more work than a sand filter, but the D.E. filter will clear a green pool about 50% faster than a sand filter. A cartridge filter will need washing several times a day and if it clogs the system will shut down so keep  the cartidge clean and swap with a backup cartidge is you are able.

5. If you follow these instructions and your pool does not clear up within 1 or 2 days, your filter may not be functioning properly. The pool will never clear up if the filter is not working properly.