I too had milky water in my pool. I also have a chocolate lab dog who loves the water. I found that with allowing the dog to swim would turn the water milky and that a "slime" would develop on my filter and in my filter housing. I can't deny the dog but I can limit the number of swims. My pool is small so it's not hard for me to fix. I change the filter or clean it real well every day for a couple of days following one of her swims. I also heavily "shock" the water at the end of the day for 2 days after her swim. If the cause of you milky water is a 4 legged friend, this has worked for me.
New answer::
Ah, yuck! Do you realize the germs on a dogs body. Milky and slime more YUCK! Extend the filter run time if you insist on having a dog swim in your pool. As a pool service person, I wouldn't even put my toe in the pool under those conditions. Milky water is caused by many things but lack of filtration is one and lack of a sanitizer is another. You are subjecting yourself to a multitude of germs and bacteria. Diarrhea, e-coli are but a few found in pools. Oh, horrors of horrors!
K
First hit it with a copper based algae side. If that doesn't start clearing it up Go to the pool shop and get a strong clarifier. Turn of the filtration equipment and cast the clarifier evenly over the water and let it settle for a couple of days. you will note that the water is now crystal clear except for a layer at the bottom of the pool. Gently vacuum this layer to waste. Do not put it through your filter. Then top up the pool.
It sounds like you have an algae infestation. Hit it with an algaecide, scrub the walls of the pool and see if the water starts to clear up. If it does not cast a clarifier over it, let it stand for two days without the filter working then vacuum the stuff on the bottom to waste. Don't vacuum it through the filter.
Sweep out any debris. Amend the chemicals and run the pump.
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Milky water should tell you its time for a water change!
Carbondioxide
Water or antifreeze.
stable amounts of glucose iodine does this.
Try hitting it with a clarifier, your pool shop will have it in stock. First hit it with an algaecide then cast a clarifier over the surface of the pool and let it rest without the pump going for at least a full 24 hours. At that time you will notice that the pool water is clear except a layer at the bottom, carefully vacuum this layer out to waste, do not put it through the filter
Water turns milky.
Lime water turns milky when carbon dioxide is added to it.Lime water also turns into Calcium carbonate (Limestone) solution
Same as the ambient air is to avoid shocking the plants.
Hydrogen doesn't turn water milky.
Yes, you should run the pump when you add chemicals to your water,
As shocking as this may sound, you would need a pond that holds at least 1200 gallons of water