No Free Chlorine & High Alkalinty

by Erin
(Delavan, Wi)

Hi, really glad I found this site and I hope you can help me.

So we had a pool put up in our pervious home and took it down and brought it with us to our new home but it took two years to finally getting around to putting up. Liner and pool were kept in excellent condition and went up as easily as it could, however now a month later and we can't get the chemicals to balance.

Hardness is steady at 200 ppm.
Free chlorine is at 0 ppm
pH is finally down to 7.5
Total alkalinty is holding at 240 ppm
CYA is at 30-50 ppm

At first the pH was at 8.4 or higher, alkalinity was at or above 240 ppm, and free chlorine was at zero. I kept adding chlorine and trying to shock it but the chlorine was always gone within 4 hours.

Cartridge pump was running while adding the chemicals. Except during the night. I was told by a friend that it was because the pH was so high.

I have finally gotten the pH to come down to 7.5 ppm and would have thought with how much Muratic Acid I added the Alkalinity would come down but no such luck, it's still above at or above 240 ppm.

I do not know where to go from here or which to start with, getting the chlorine up or lowering the alkalinity.

Thanks for the question Erin

Your friend is right. Chlorine reacts better when the pH is below 8.0.

Having a high total alkalinity (TA) causes a couple of problems. First the pH will rise quicker. This means you'll be going through much more acid trying to keep it below 8.0.

2nd, the chlorine will be much less active when the TA is high. You need to get the TA down to 80 - 100ppm, 120ppm being the top.

The question doesn't say how big the pool is, but it's 0.8 qrts. of acid to reduce TA 10ppm per 10,000 gallons. You need to reduce the TA by a minimum of 140ppm which is going to require some acid, so be prepared to make several corrections and
have patience with this.

Get a good test kit for yourself. I use and recommend a Taylor K-2006 kit. You can also take a sample to your local pools store to compare what you have.

Pool Water Testing

Water Testing Kit

Get a 5 gallon bucket and fill with 1/2 pool water. Add the acid, mix with a stick and add to the deepest part of the pool with the pump off. Gently sweep the bottom to break up any hot spots of acid. Let it sit for 3 - 4 hours, then pump back on to FILTER for 8 - 10 hours. Retest and make another adjustment.

Pool Alkalinity

Total Alkalinity

The TA may come down 30 - 40ppm, but you'll be on the right track. I tell people not to make a huge adjustment because you may overshoot the mark and need to add bicarb to increase the TA. It might take 3 - 4 applications to get your TA in range. This is where patience comes in handy.

All of your other readings seem good, with the exception of the chlorine. While this process is going on with the TA, you might want to invest in a PolyQuat 60 algaecide. The cheaper algaecides have copper and metal fillers so don't use them. When you get this under control you should be able to stop using the algaecide and go back to normal pool maintenance. An algaecide is not something you need on a regular basis when the chemical readings are in order.

The hardness is fine so there's no need to add any hardness up or calcium chloride.

This sounds like new fill water so it shouldn't be that difficult to get the TA in line.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Cloudy, Milky, Discolored Pool Water" category.

Check back to this post for updates or answers.

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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Swimming Pool Question..Chlorine Is Low..pH Level Is High?

by Christie

I just got my swimming pool completely filled up this morning put a chlorine tablet in the floater.

I tested the pool water with test strips a couple of hours after putting pool chlorine in and everything looked fine except it showed lowest chlorine level 0/0 and pH level at the highest level 8.4.

What to do?

It is an 18 ft. 42 in. swimming pool and holds about 5500 gallons of water.

Thanks for the question Christie

I can probably say your fill water has a high pH level of 8.0ppm - 8.2ppm.

Here in central Oregon we have a pH level of 7.8ppm - 8.2ppm and a total alkalinity of 30ppm.

You need to put enough pool chlorine in to get the level up to 1.5ppm - 3.5ppm, and get some cyanuric acid (CYA) in their as well.

You can do this by using Tri-Chlor pool tablets or Di-Chlor powder.

Di-Chlor to initially get the CYA in there and the swimming pool tablets to keep the level up.

Swimming Pool Chlorine Tablets

Also, get a Taylor Reagent FAS-DPD K-2006 test kit.

It's the most accurate and will give you the best readings.

It takes some time getting used to but it's worth the time investment.

Water Testing Kit

You can adjust your swimming pool pH level using this link:

Swimming Pool pH Levels

Hope this helps and have a great Summer


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