Cloudy Water Keeps Returning!

by Arlene

Our TDS were high last year, so we drained the pool about half & they still seemed to be a little on the high side. We are going to drain again this week, but I just want to be sure we are doing the right thing.

I think we are after going over your website for the last 2 days. (thank you by the way) I've had it with the pool stores, I'm pretty sure and am going to order the test kit you recommend and try to keep it maintained myself.

We put 12 gal of liquid chlorine in before our party Sunday & by Monday it registered 0. Put in 8 gallons on Monday night & now we have .3 reading. Water had never been totaly clear. Some days better than others.

Only for about a week could I actually see the bottom at the deep end.

Here are the results from the Pool store analysis.
Sat idx 0.4
TDS 4200
CYA 41
Tot. Chlorine 0.3
Free Chlorine 0.3
ph 7.8
Tot. Alkalinity 140
Adj. Total Alk 128
Tot. Hardness 270

We have a sand filter. Our pool is 16 X 32 in ground with a vinyl liner. Approx 18,000 gal.

Thanks for all your help.

Thanks for the question Arlene

The TDS are nearly 3Xs higher than what is normally considered acceptable. You have 4200. Arizona has very hard water, about 300 - 400ppm, so many people need to do a full drain and refill about every 2 - 3 years. There's alot of debate on whether to drain or not drain the pool when the TDS is over 1500ppm. Without knowing exactly the make-up of the TDS, some say it's pretty useless. High salt levels will give a high TDS but won't make the water cloudy.

The alkalinity (TA) is a bit high, but nothing to worry about. Hardness is a bit high at 270ppm. I recommend between 150 - 250ppm for plaster pool. For vinyl and fiberglass, there's no reason to go over 100ppm.

Here's what you want to look for. I would recommend doing a 1/2 drain and refill, but by doing this you're diluting 1/2 of the chemicals, specifically the CYA and hardness. Without know the pH and alkalinity of the fill water it's a little hard to tell what will happen. Most public water companies keep the pH around 7.2 - 7.4 so that may have little effect on your pool pH.

Test the alkalinity of the fill water and let's use common sense. If the TA is high, maybe over 150ppm or so, then your pool water TA will increase. If it's low, say around 20 - 30ppm, the TA will decrease. The TA
you have right now is a bit high, but nothing to be concerned about. You want it between 80 - 100pm, 120 being the top.

Once you do a 1/2 drain and refill, the CYA will be cut in half as well, maybe down to 20ppm. Shock the pool using dichlor. This is a stabilized chlorine that will put CYA into the pool. When you get to 30 - 40ppm, stop using dichlor and go back to liquid chlorine.

The trick is to get and keep the chlorine above 10 - 12ppm for a period of time. As per your question, you put 12 gallons in and registered 0. Then another 8 and got a slight reading. Once the CYA is in range, you'll need to manually dose the pool with chlorine to keep it at 10 - 12ppm. Make the adjustment at night, then retest int he morning. Be sure to have the pump running 24/7.

You'll notice the chlorine level will start to hold longer and longer. It must if the pH is 7.6 - 7.8, TA between 80 - 100ppm and CYA between 30 - 50ppm. be sure you using enough to get to 12ppm and not too much more. There's no chlorinating difference between 12 and 20ppm, only the amount of chlorine used.

Here's a chart for your size pool:

Swimming Pool Chlorine

Your pool is 18,000 gallons, so bare minimum would be 2 gallons to get it to 10ppm. I'd go 2.5 - 3 gallons at a time and no more. Anything over that and you're wasting money. 1 gallon per 10,000 to bring it to 10ppm is the norm. Filter 24/7.

There could be dozens of reasons why a pool goes cloudy. Most of the time it's an early sign of algae:

Cloudy Pool Water

Get the chemicals in line, then shock the pool consistently. This is where many pool owners fall short. Shocking is not a one time deal, it's a process. By dosing the pool day after day, you'll start to see a difference and the chlorine will hold. Just be sure everything is right and the CYA is 30 - 50ppm. Be sure to document everything (dates, times, amounts, etc...) so you can see a pattern developing.

Be careful when draining a vinyl pool. I recommend doing it in stages, maybe drain 6 - 8" then refill, then drain another 6 - 8". Put the fill hose at the furthest point from where you're draining.

If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.

Contact Me


Hope this helps and have a great Summer.


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Put In Too Much Super Water Clarifier

by Charlotte Brown
(Riverside,Ca. USA)

I have a above ground pool about 1500 gallons. My sister put in a whole bottle, 32oz.'s, and I want to know what I should do and if it will hurt my filter and when can we swim in it.

The bottle said only put 1 oz. to every 5000 gal.'s so now you can see she put way too much in.

Thanks for the question Charlotte

If you have a clarifier that is based on an acrylic acid polymer, it will have a tendency to make your pool cloudy if overdosed. An alum-based coagulant work the best, if you're going to use a clarifier. Try to allow the pool to sit for a few hours, or leave the valve in the RECIRCULATE position.

To can vacuum to WASTE, and keep your pool topped off because you're going to lose water rapidly. If this doesn't work, being that it's only 1500 gallons, you may want to drain 1/3 - 1/2 of the water, refill, and balance the chemicals.

Was your pool cloudy to begin with? If it was, then a clarifier will only cover up the real issue. We need to figure out why the pool was cloudy and how to resolve that without adding more chemicals into the pool and more expenses on your part.

Cloudy Pool Water

With good pool chemistry and weekly maintenance your pool should be crystal clear. A clarifier should only be used in extreme circumstances.

To post a reply, or if you have a similar question, you can see your post (Put In Too Much Super Water Clarifier) on the Q&A page in the "Cloudy, Milky, Discolored Pool Water" category.

Swimming Pool Questions and Answers

Check back to this post for answers.

Hope this helps and have a great Summer.


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