What caused the cloudiness

[Dcsmitty]

This is my 3rd summer with an in ground pool. The first 2 summers I had minimal issues and a bout of cloudiness that cleared up with a shock treatment. I use a home test kit and test my water once a month at the local pool store.

However about 2 weeks ago I developed cloudy water that I couldn’t clear. The day it started to cloud the chlorine was really low. I tried multiple shock treatments and clarifiers but no luck. The water was just cloudy, no algae growth, no slimey water. I couldn’t see the bottom of the 3 ft shallow end cloudy.

I took a sample to the local pool store to get some advice (I will post a picture of the results). The results showed low chlorine, ph on the low side and sky high phosphates. I added their recommendations and after a week the pool was still extremely cloudy. I know it will be asked I typically backwash my sand filter weekly, but during this episode I backwashed and rinsed every morning. Also I replaced the sand mid summer 2022 with zeo sand.

After some googling I decided to try a flocculent. About 24-36 hours after the water was cleared. I then vacuumed to waste 2 times cleaning the flocculent from the bottom. Pool still ended up a little cloudy after the vacuums. I then double shocked and 3 days later the pool is now crystal clear.

Today I took another sample to the pool store and the results are very similar to those a little over 2 weeks ago. The phosphates still show 3000 even after over 2 quarts of phosphate remover. My question for the experts is, what caused the cloudiness? The water samples are similar and one was extremely cloudy water and the other sample is crystal clear.

Here is a picture of the test results. The result column is from today.

 

[Newdude]

Hey Smitty and Welcome !!!

You mentioned testing at home. What are you testing with ?

 

[Dcsmitty]

Home pool test kit with the drops, not the strips. Test chlorine, ph and alkalinity with it and the other stuff at the store

 

[JJ_Tex]

Welcome. Can you post your results? If you don't know, we don't think much of pool store testing or their advice.

Generally speaking, the cloudiness is suspended algae in the water. Algae is caused by chlorine being too low and you will need chlorine to kill the algae. Note the pool store will try to confuse you and sell you all sorts of stuff you don't need like algaecide, flocculant, phosphate removers, clarifiers, and cool-sounding magic potions like "green to clean".

 

[Newdude]

Home pool test kit with the drops, not the strips

Awsome. Which kit ? Does it have the fas/dpd (powder) test for FC, or only the color matching block test ?

Does it have a CYA test ?

If no to either/both, you'll need to add those on as the FC/CYA relationship is paramount to clean water.
FC/CYA Levels

Peep out what we do with the right test kit How Clear is TFP Clear? we'll help yours get there too, every step step of the way.

 

[sande005]

Just using the pool store results as an example (which as you've gathered, nobody trusts) -

Your Cyanuric Acid (CYA) is way too high. More reading here will reveal that the higher it is, the higher your Chlorine must be to have any effect. Pool store core recommendation of 40 is reasonable, but their acceptable range goes too high. If you are really at 105 you're off the scale of what is recommended here, and your Free Chlorine needs to be at least 9, and likely higher. Pools store says you are at .2, or hardly any at all. Hence the algae.

But, before panicking - you need to do your own testing to validate (or not) what the pool store said. Read up in the links about good test kits, and get one. For now, come back with what kind/brand of tests you've already got, and what readings you get. Then we can make a start on recommendations both for test kits (or additions to what you have) as well as some basics on improving things in the pool.