Cloudy Water In My Salt Water Pool

by Eva

Cloudy Water In My Salt Water Pool

by Eva
(Wyoming)

I have a 14,000 gallon salt water pool. We have been experiencing cloudy pool water for months now.

We are located next to a river and our pool has a hydrostatic relief valve.

As you know there is alot of flooding going on right now and even though we are not flooded, the river level is much higher than normal.

We cannot maintain an acceptable pH level without chemicals, nor can we maintain an adequate amount of chlorine without chemicals.

We have shocked several times, used a sequester, backwashed (even though the sand filter did not have a high head preesure).

We have been reading our pool every 2 hours the past two weeks to try and get ahead of the problem and still the water is cloudy. When I backwashed I let it run for a full hour emptying about half the pool.

We refilled, added the correct amount of salt, adjusted the pH, and the chlorine, and let it run 24 hours, then I did the tests on the water.

These are the results:

pH 7.2

Alkalinity 210

Calcium hardness 200

My pool temp is 83 degrees (normally 80) and my salt content 3000 ppm. My pool guy came in and had me shock it again but it has almost burned off and there is still no change. When I drained the pool I noticed no rust stains or algae.

I vaccum the pool every night and brush the walls daily. I have cared for this pool for the last 2 years and have not had this problem before. I dont know what more I can do.

Is the river water contaminating my pool via the hydrostatic relief valve? I have inspected my high pressure sand filter and found the sand to be pretty much level and filled to the proper level with the right grade of sand. There were no holes in the sand that were visible. We chemically dose the pool throughout the day. What are your thoughts?




Thanks for the question Eva. And very nicely written. First, for other visitors that may not know, a hydrostatic relief valve is located in the deep end of the pool. It can be found under the main drain or a box on the bottom of the pool.

Its purpose is to relieve the build up of pressure from underneath the pool. If the pool was drained with a high water table, the pool may float up or crack.

The hydrostatic relief valve then opens and allows the ground water to enter the pool. This keeps the balance of the pressure between the
ground and pool (equilibrium) and to relieve any built up pressure underneath the pool.

That being said, I would suspect that you may have a faulty hydrostatic relief valve, but there could be a hundred reasons why your pool water is cloudy. Considering that, I have never personally repaired a hydrostatic relief valve. My pool route was in Arizona where it only rains about 8 inches per year, so I didn't have an issue like yours.

Other pool guys that I knew were familiar with them, but they really never discussed it because it didn't pertain to Arizona. The flooding will cause the water to rise to the top. We have that problem in Oregon where we get about 40 inches of rain per year. I drain the YMCA pool each September, do repairs, refill and balance it out.

We can't do it in January because of the water table being so high. Be sure when you shock you're getting to the super chlorination level.
Check the chlorine stabilizer/cyanuric acid (CYA) and try to keep that between 30 - 50ppm.

Use a good metal sequestering agent only when you have metal (iron and copper) in the water. Take a sample of pool water to your local pool store for analysis. If metals are found, you can use a good metal sequestering agent like Jacks Metal Free or Metal Wizard.

These agents won't get rid of the metal, but it keeps it in solution, or suspension, until it can get filtered and backwashed out.

Be careful backwashing so much. Each time you backwash you lose a little bit of sand. Sand filters need just a little bit of pressure to run properly.

If you need to lower the pool level, try putting the valve to WASTE or renting a pool pump. This bypasses the filter and you won't lose any sand.

Another thing would be the alkalinity. 210ppm is a bit high and might be contributing to your cloudy pool water. You want it in the range of 80 - 100ppm. Your calcium level is in line, but don't allow it to go higher than 250ppm or you'll run the risk of burning up the salt cell.

It sounds like you've done everything right the last 2 years, and if the only variable is the flooding, then I would suspect it is a faulty hydrostatic relief valve that is allowing river water and possibly contaminants into the pool.

I would encourage you to find a local pool store that can handle the repairs. I can't tell you how because that is one area I've never worked on.

Hope this helps and good luck with your pool.

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