Persistent Cloudy Water...now worse

[TN Vinyl Pond]

Thank you for your help! I have used nothing in the pool but 6% bleach, Borax, baking soda and granular stabilizer. My filter runs about 7.5 lbs of pressure after a backwash and doesn't really seem to rise very much even after vacuuming or letting it run for a week or more. I have back washed about once a week or so even though the pressure doesn't really seem to rise more than a pound or so.

[Watermom]

I'm wondering if your gauge is working properly.

When you backwash, is the discharge water dirty?

Do you know if your sand filter has enough sand?

Have you tried turning the pump off and seeing if anything will settle?

Have you had any periods of time where your chlorine dropped too low?

[TN Vinyl Pond]

I'm not sure about the gauge working correctly although I just bought it new and installed it.

Yes the water does run dirty for four or five minutes when back washing.

I do not know if the filter has enough sand although the previous homeowner claims that it does but considering the source... I DON"T KNOW.

I have not tried turning off the pump.

Yes, until I got the CYA built up it would drop to almost zero after a day in the sun.

Thanks

[Watermom]

You might check to see if your filter has enough sand in it. How old is it, any idea? You typically do lose sand over time with backwashing.

Let's also have you do the overnight test. This evening, test your water and add enough bleach to get back to shock level. Then, in the morning within two hours of sunrise, test chlorine again and see how much you lose overnight. Also, please test CC in the morning. Report these readings. If you are still losing more than 1ppm of chlorine overnight and have more than 0.5ppm of CC, then you are still fighting something in the water.

Then, tomorrow, we may see about turning the pump off for awhile to see if anything will settle to the floor that can be vacuumed to waste.

[TN Vinyl Pond]

I will have to check the sand. I know the filter and pump were replaced about two years ago but there is still no telling what is in it. I know that when I try to vacuum algae some blows through and the water becomes more cloudy. I tried to test it with DE though and didn't notice any of that coming back in through the return.

Added bleach last night to 15PPM, this morning tested 14PPM and no sign at all of CC.

[Watermom]

Good news on your morning testing results. Yes, do check the sand level.

[TN Vinyl Pond]

I have never been into a filter. How would I determine if it would be better to replace the sand or just add more? Also what level do I fill it too?