Cloudy water is one of the most common problems pool owners face. There are three main causes of cloudy water.
- No chlorine or bromine
- Filter not functioning properly
- Dissolved air
In this blog post we will advise you on how to restore the sparkling look to your water.
The first thing to do is check your chemical levels and in particular the chlorine, pH, alkalinity and stabiliser (cyanuric acid).
If the chlorine or level is low, shock the pool with 500 grams of chlorine shock per 10,000 gallons of pool water. (For a very cloudy pool it may be necessary to use double this amount or more.) Leave the water to circulate overnight and re-check the chlorine level to ensure it is at least 5 ppm. If the stabiliser level is very high on the test strip then you will need to replace a portion of your water with fresh water to bring it down. For all the other parameters make sure they are within the required limits as stated in the table below.
||7.2-7.6 (7.2-8.2 if you are using Bromine)
If all your parameters are within range then the cause of the cloudy water is probably down to fine particles of debris or material passing through the filtration system. When the water passes through the filtration system the role of the sand, EGFM or cartridge is to trap any debris or material and prevent it from returning into the pool. Sometimes these particles are so fine that they pass straight through the filter and re-enter the water. These fine particles are the cause of the cloudy water. This is particularly common when you have had to shock your pool to kill a lot of algae or if you have had a lot of people using your spa.
In order to eliminate these particles and restore water clarity a flocculant needs to be added to the water. The flocculant (also known as a coagulant) enhances the removal of the fine particles by clumping them together so they form a flocculus (floc) which is more easily trapped in the filter.
If after checking your chemical levels and adding a flocculant you still have cloudy water, then you need to check your filtration system is working properly. If you have an above ground pool or spa then remove the filter cartridge and give it a thorough clean. If you have an in-ground pool you will need to check that your pump is working. You can do this by seeing if there is water coming back into the pool via the inlet. If the pump appears to be working then back wash the filter and then remove the lid to check the level of the sand. When checking the level of the sand always use a tape measure as when the filter is full of water it looks as though the sand is closer to the top than it is. Your filter should be two thirds full of sand. Whilst doing this also observe the state of the sand. It should be clean, reasonably level and should have no gaps or holes in it. If the sand level is not as described above, the filter should be emptied and the distributor at the bottom should be checked and repaired if necessary. Finally new sand or EGFM needs to be added to the filter.
The last and least common cause of cloudy water is dissolved air. This is caused by a leak on the suction side of the pump where air is sucked in and dissolved in the water when it passes through the pump. When the water gets back to the pool it forms very small bubbles which are suspended in the water making the pool look cloudy. Pools with dissolved air also tend to foam when the water is disturbed. The most common place for a leak to occur is the lid of the strainer. To check for this turn off the pool pump and close the valves. Remove the strainer lid and examine the seal. Wipe the seal and put some vaseline on the seal before putting the lid back.
The other common place for air to get in is the mechanical seal. Check under the pump for evidence of water leaking. If it is leaking you will either have get a replacement mechanical seal or a new pump.
If the strainer and pump are OK check all the pipework from the pool to the pump for leaks on joints or cracks in pipes.