Chlorine Demand

[gfritz1]

Janet - will return from work in kY on Friday and will address the pool.Part of my issues is have been working in KY away from home and treating the pool remotely . I am debating about doing a partial drain on my return to get the cya down a little realizing that it is costly . Whats the advantage of doing this or not doing it? I think the cya is probally higher since these readings as have been eating tri clor tabs at a rapid rate

I am looking at using lithium shock since have a supply but unsure enough to raise the leave to 20 ppm and maintain it. Where can I find a formual to calculate the amount needed to bring my pool to 20 at 23000 gals? If I understand correctly I need to start at night and keep feeding the chlorine to keep at 20ppm until the next morning? Sounds like I raise to 20ppm and keep measuring and adding as it drops to get above 20 for a 12 hr period? Then keep at 5 ppm
As for not using tabs you say use bleach .What amount and at what frequency ? Thanks as cant wait to get this behind me. One more questions A&H Baking soda compared to Borax or to PH+ what is the difference as I really need to get my PH up

[Watermom]

In your pool, each gallon (4 quarts) of plain, unscented 6% bleach will add about 2.5ppm of chlorine. Use that as a reference to help you figure out doses of bleach to add. Each time you test the chlorine, add enough bleach to get back up to shock level. You want to keep doing this until you can go from sundown one evening to within two hours of sunrise the next day without losing more than 1ppm of chlorine overnight. Then, keep the chlorine high for one more day for added insurance and then you can let the chlorine drift down and make sure to keep it between 5-10ppm ALL the time. (See the Best Guess Chlorine Chart in my signature up in post #2 for info on the relationship between CYA and chlorine levels.)

20 Mule Team Borax (laundry aisle at Walmart) is used to raise pH and baking soda is used to raise alk.

[gfritz1]

OK THANKS for the help -I did a partial drain upon returning as took down roughly 15inches and refilled starting Friday soi refill was Sunday and Sunday night and Monday added the 20 Mule Team . It took roughly 8 lbs (2 boxes) plus a 5 lb PH+ I had but it is now 7.8 and holding .AMAZING .Last night at dark with a FC of zero added 8.5 gals of bleach and 2- 15000 bags of shock . FC was above 20ppm and by daylight it was still above 20ppm.Extremely sunny day in PA so pool has been in sun all day .It sparkles. My present readings almost 24 hors after super shock FC 12.5PPM CC 0 TC 12.5 PH 7.8 Hardness 190 Alk 140 and cya 72. So FEEL PRETTY GOOD NOW . The chlorinator is off and empty . So what do I do now to continue ? I know you said no more tri chlor or the shocks others then lithium or bleach. What do I use to replace the chlorinator for daily treatment? I assume still add alegcide on weekend and the shock (bleach-how much?) .This is amazing -await your response - GFritz1

[Watermom]

Just use bleach for your daily chlorine. With a CYA of 72 (how did you get that number??), you need to keep your chlorine levels between 5-10 all the time. You do not need to use algaecide and you also do not need to routinely shock unless you are having a CC reading greater than 0.5, cloudy water or see the beginnings of algae. If you maintain your chemistry properly, you rarely need to shock.

[gfritz1]

CYA was measured with the Taylor Test Kit and looking until the Black Spot disappears. The Pool place got 50 using test strips .

Understand to use the bleach so this means daily check of chlorine level and then based on reading add bleach with each gallon expected to raise my ppm by 2.5

Is there a better time to add the bleach? I normally run pump from 7am-7pm and the swimmining usually is from 2-6 but normally only adults doing laps. I understand need to keep higher but like this weekend grandchildren will be here. Whats the safe limit for them to swim-upper ppm level -----thanks again

[Watermom]

The best time to add bleach is in the evening when the sun is off the pool. In that way, all the chlorine can go to oxidizing the goo in the water and none of it will be lost to the sun. However, it is also ok to add it at other times. Especially when a pool is fighting algae, or has a high chlorine demand for some reason, etc.

Keep your chlorine between 5-10ppm. Your grandchildren are perfectly safe when swimming with chlorine at those levels with a CYA of 70ish. (Actually, it is also fine to swim when chlorine is at shock level but you probably would want to wear an old swimsuit if you did so.) People are often afraid that a chlorine level of 5-10ppm is too harsh; but the fact is that with a CYA of 70, chlorine is no harsher at 5-10ppm than it is at 1-3ppm with no CYA.

[gfritz1]

Well its been 8 days since we did the partial drain and the shock using bleach to above 20ppm . The water has remained excellent and the grandchildren were here for weekend and enjoyed three days of swimming .I am losing about 2-3 ppm per day of FC as each day need to add roughly 1 gal of bleach (6%). Is this normal ? Weather was actually more overcast than sun . I have been able to hold between 5 ppm and 9ppm by moring add of bleach.My new readings Sat were as follow
My cya appeared to increase to 80 which I was suyrprised as no tabs are bing used and teh chlorinator is actually turned off
PH is 7.8
FC was 5.6 and CC was o
Alk was 150
Hardness was 170

Have not added anything other then bleach

[PoolDoc]

I am losing about 2-3 ppm per day of FC as each day need to add roughly 1 gal of bleach (6%). Is this normal ?

That's on the high end of normal . . . but still normal. You may find the results improve if you lower the pH some. If you'll fill out the pool chart

Pool Chart Entry Form

I'll try to look and see what you might do to improve the situation a little.

Something else you can try: adding large doses of bleach in the late evening, via the skimmer. This can help clean out any 'goo' in your filter. Again, if you'll complete the chart, I can calculate doses.