Chlorine

[cardsfan]

Need some advise. Got 6" of rain here Friday and Saturday. Sunday is my weekly shock treatment day so I did. After 2hrs chlorine was .5.Put in 2 3" tablets Monday and chlorine is at 1 today. My question is with that much rain should I shock again. 20,000 gallon inground, 2lbs of shock on Sunday.

Thanks

[polyvue]

Need some advise. Got 6" of rain here Friday and Saturday. Sunday is my weekly shock treatment day so I did. After 2hrs chlorine was .5.Put in 2 3" tablets Monday and chlorine is at 1 today. My question is with that much rain should I shock again. 20,000 gallon inground, 2lbs of shock on Sunday.

Thanks

There are some key pieces of information missing: When you state that chlorine = .5 do you mean Free Chlorine (FC) or Total Chlorine (TC) or something else? Also, what is the level of CYanuric Acid (CYA)? The latter is important because if you're using Trichlor tabs or powder as a chlorine source the pool may already have so much CYA (it's compounded with the chlorine in TriChlor and DiChlor products) that your weekly shock regimen is no longer effective. These short articles may prove useful in determining whether your current process fits best practices:

http://www.troublefr...s_chlorine_pool

http://www.troublefr...cking_your_pool

How do you know when to shock? If the pool is clear (rain or no rain) and there is less than 1 ppm Combined Chlorine (CC or chloramines) as determined by testing (a FAS-DPD chlorine test is easier and much more accurate than test strips) and your FC (Free Chlorine) has not dropped precipitously, there is no need. Though it's tempting to rely on instructions found on shock or chlorinating tablet packages they can't anticipate the pool's current chemistry; that's why procuring and using a high-quality residential test kit (Taylor K-2006, for instance) is paramount.

[AFiremanFirst]

I completely agree with polyvue. I know techs that shock just to be shocking? Why? Chlorine is the most expensive chemical we use. When I shock... and I mean super-chlorinate (ie 10x my chlorine level usually 7.5+ lbs at a time) It's with good reason, like algae. Otherwise I can't support shocking weekly just to be shocking. 100lbs of shock will last me almost all season on 20 pools. Don't through your money way. Your pool is an investment, okay a money pit, anyways. Don't compound your financial obligations to it with wasted shock.

[cardsfan]

Sorry it took me so long to post back with the info I left off. tc .4. fc 0, cya 70, alkalinty 118.. ph was 8 today added ph down. Have not checked ph again since I added it today..

[polyvue]

Sorry it took me so long to post back with the info I left off. tc .4. fc 0, cya 70, alkalinty 118.. ph was 8 today added ph down. Have not checked ph again since I added it today..

St Louis? (just noticing your username)

What type of test kit or meter do you use to get these measurements? If your pool has .4 PPM Total Chlorine and 0 PPM Free Chlorine, you have no active chlorine in your pool. This is precarious because it is the Free Chlorine that does almost all of the sanitizing and oxidizing and prevention (of algae and bacteria/viral growth). With a reading of 70 PPM Cyanuric Acid (CYA) you should have at least 5 PPM of Free Chlorine in the pool at all times. If you reduce CYA (over time via backwashing or splash-out-- or right away, by draining some pool water) the required level of Free Chlorine drops, and you'll have an easier time shocking the pool if the need presents itself.

The relationship between CYA and Chlorine is explored here. In addition to the links suggested in my last post, I recommend that you read ABCs of Pool Water Chemistry. It's not just for beginning pool owners... though its content may be a bit foreign to what you've learned from other sources. You're right, of course, to keep your pH down below 8. Reducing your alkalinity (TA) further should help stabilize the pH.

[cardsfan]

I have a ps234 test kit. Pretty sure my results are good reading because the wife took a water sample late yesterday to the pool store (dont think she trusts me) and their reading were almost the same as mine. They told her something in pool was consuming the chlorine. Their advise was to add 3lbs of shock. And if cholorine does not come up in 24hrs to double the shock treatment. I'm still an newbie with the pool only second year but I think I've done ok. Let me ask you another question, Polyvue, what type of pool products do you use. I used pool life last year but switched to bioguard this year. Probally catch alot of crap over the chemical question. But thanks again for your help. Love the links dont think you can have to much info on pool care.

[polyvue]

I have a ps234 test kit. Pretty sure my results are good reading because the wife took a water sample late yesterday to the pool store (dont think she trusts me) and their reading were almost the same as mine. They told her something in pool was consuming the chlorine. Their advise was to add 3lbs of shock. And if cholorine does not come up in 24hrs to double the shock treatment. I'm still an newbie with the pool only second year but I think I've done ok. Let me ask you another question, Polyvue, what type of pool products do you use. I used pool life last year but switched to bioguard this year. Probally catch alot of crap over the chemical question. But thanks again for your help. Love the links dont think you can have to much info on pool care.

A few years ago, after doing a lot of reading in this forum, TFP and PoolForum, I elected to install a salt water chlorine generator (SWG), so that's what I use to chlorinate on a regular basis. Though I have in the past used TriChlor powder (Leslies' Genesis shock) my CYA levels were very low at the time, so I wasn't concerned about adding too much cyanuric acid in the pool.

If I didn't have a SWG I would use either 12% pool chlorine or 6% clorox unscented bleach or generic equivalent and check the chlorine levels at least twice a week. The SWG lets me test only once a week and only in the winter do I need to supplement its output with bleach. The only chemical I add nearly every week is muriatic acid (MA) 31.45% -- to keep the pH down to a reasonable level.

What else? Calcium chloride to increase CH (rarely needed). Bicarbonate of Soda ("Alk Increaser") to raise TA (rarely needed). 100% Cyanuric Acid granules (aka "stablizer" or "conditioner") to increase CYA. Only add this stuff when the CYA goes down below 40-50 ppm. Sodium Tetraborate (20 Mule Team Borax) to increase pH. I hardly ever need to raise pH.

There are pool owners on this forum and others whose seasonal (annual) cost for chemicals is less than $75-$100. It's hard to accomplish that with name brand chemical treatments. Besides the cost, practicing the so-called "BBB" protocol delivers an easier way to treat pool water.