Confused

[newbiepool]

We filled up our Intex pool (6500 gallons 18x48) with well water and finally got it cleared up and we were using bleach but I felt like I was adding it every day so we switched to some chlorine tablets in the skimmer. We had added CYA and today it tested at 55, pH is 7.2, Chlorine is ZERO. I don't know what we should do to get our Chlorine up and keep it up. Maybe it is easier to just use bleach...I'm so confused. Can someone help me figure this out? Thx.

[AnnaK]

Most of us do think it's easier to use bleach. Some people can buy liquid chlorine in 5 gallon carboys at a pool store. That chlorine has a concentration of around 12% and you use less of it, and you don't have the hassle of bleach bottles.

Your CYA is good. The chlorine tablets in your skimmer will continue to raise the CYA and lower the pH and yours is already at the very low end. I'd stop using the tablets. Get some 20 Mule Team borax and add 1 1/2 cups. Let it circulate for an hour, test pH again. What is your TA?

Each gallon of 6% bleach will raise the FC by approximately 10 ppm in your volume. 1/2 gallon would be 5 ppm and that is the level of free chlorine you want to maintain with CYA at 55. How often and how much to add bleach depends on so many things that we really can't tell you. Test FC and pH daily, keep a log in a notebook or digital file, add bleach as necessary to keep the 5 ppm.

If this were my pool I'd put a gallon of bleach in it right away just to forestall an algae outbreak which will happen very quickly without any sanitizer in your water.

[newbiepool]

Thx..I am off to get more bleach and borax. I'll post back TA and pH..thanks! :)

[aylad]

Most folks who use bleach do add a maintenance dose every day, usually in the evening after the sun is off the pool. The only way to use bleach without having to add it daily is to increase your CYA to a higher level so that it last longer--but I would not do that with a metals pool because it will be a total nightmare if you let algae get started because of the high levels of chlorine needed to shock.

[newbiepool]

Our pH is about 7.5, FC 6-10, TA took about 30 drops to get from green to pinkish red. I am using the HTH kit from Wal Mart.

What kind of main dose should we add each eve? thx!

[AnnaK]

I'm not sure how to interpret your HTH test results. pH at 7.5 is good. FC "about" 6-10? With a DPD powder and FAS drop kit there isn't any 'about'. I have never used an HTH kit and so I can't really question or discuss the results.

Wild guess? Add 1 quart chlorine at night, test in the morning. If you're between 3 and 6 ppm FC, you're good. If you're below 3 ppm, add 1/2 gallon, instead. The chlorine demand changes depending on how much the pool is used.

[aylad]

If your FC is higher than the 5 ppm the kit will measure, here are the instructions to force it to read higher levels of chlorine...

http://www.poolsolutions.com/gd/how-to-test-your-pool-without-a-good-testkit.html

[AnnaK]

Thanks for the reminder, Janet. I forgot the HTH kit limitations on chlorine testing. Now I understand the 'about'.

[newbiepool]

I really just need to get the good test kit from Amazon. The FC color was at the top which is 6-10. What about the TA at about 30?

[PoolDoc]

In an vinyl pool, TA just functions as pH stabilizer -- and if you pH isn't bouncing all around, it's not something to worry about.

[aylad]

Just to reiterate, to make sure you didn't miss it--with a CYA of 55, you need to keep a minimum of 5 ppm chlorine in your water at all times. Anna gave you some basic doseages and the results, so you need to test the water daily, and add whatever amount of bleach you need to get back up over 5 ppm. (I would dose it to about 8 ppm in the evening just to give you some wiggle room).

Janet

[AnnaK]

Our pH is about 7.5, FC 6-10, TA took about 30 drops to get from green to pinkish red. I am using the HTH kit from Wal Mart.


Because I am not familiar with the HTH kit I would like to ask you or someone who does use this kit how TA is tested for. The Taylor kit I use values each drop of titrant at 10 ppm. If, with my kit, I counted 30 drops to get from green to red (or pink) I would have a TA of 300. I just want to make sure that we're working with the right number.

[aylad]

Anna, unless they've changed the test, the math is the same as what we use--each drop is 10 ppm.

Janet

[AnnaK]

Thanks Janet.

Newbiepool, that means at 30 drops your TA is 300 ppm. That means your well water is highly alkaline unless you've put something in the pool water to account for this number. In the pool it can show up as total dissolved solids (TDS) and make the water look mildly cloudy. It can also cause scaling or corrosion of metal parts. There are ways to bring that down but if your well water is highly alkaline, every time you top the pool off you're adding it back.

I would like to ask for input from the mods or Ben as to how, or even if, the alk should be managed.

[aylad]

I'm sure Pooldoc will offer an opinion here, but as far as I'm concerned, if the pH is stable, and there are no other apparent problems from it, leave it alone. You can fight the battle to bring it down, but as Anna pointed out, everytime you top the pool off, it's just going to come back up again...so if it's not creating problems for you now, I wouldn't worry about it.

[Watermom]

By the way, Anna, the HTH 6-Way kit just uses an OTO test for the chlorine.