adjust cya before or after shocking

Hi,
I have an inground pool with SWG and vinyl liner. Since I live in Alabama, we don't really close our pool over the winter. We actually were in the pool in March :) My CYA is 30, and I have a little green algae which I really struggled to get rid of last summer and early fall. Not sure I got it all because it's in there now. My FC is 5, Ph is 7.6, and TA is 80. Should I get CYA to 70 before shocking with bleach to get rid of the algae or should I shock then add CYA?
Thanks so much. The website and forum have been extremely helpful.

Hi Kateyru, and welcome to the forum!!

I would shock with bleach to get rid of the algae, holding it at shock level until you are no longer lose any chlorine overnight (measuring it after sundown and again in the morning before the sun is on the pool). Once the algae is gone, then raise your CYA.

I would go after the algae first and then raise the CYA after you're done, it should take less bleach to get to your shock level with a lower CYA. If dichlor shock is cheap in your area, you may consider using it to start your algae battle - it will add CYA as well as chlorine. Be sure to watch your CYA and pH if you do.

Will do, thanks!

Okay, I added dichlor last night. I tested ph this morning and it is way up...at least 8.2 (as high as my kit goes). I thought dichlor would lower the ph??? Should I add muriatic acid this morning?
Thanks.

What is your chlorine level? If you test pH when they chlorine level is high, you can get false pH readings.

at least 10, it doesn't look much darker than that

10? What are you using to measure chlorine? What kit? How much dichlor did you put in? Do you know how many gallons your pool is?

I am using Leslie Basic Poolcare OTO test kit (made by Taylor). I misread, chlorine is 5 but that's the highest on the kit. I added 37 oz. of dichlor. Pool is about 22,000 gallons. thanks!

According to The Pool Calculator 37oz of dichlor will add 7ppm of FC and 6.4ppm CYA to your 22,000 gallon pool and drop the pH by 0.27. You may be able to use this dose of dichlor 4 or 5 more times before reaching your CYA goal.

I think you're going to need unstabilized chlorine - Bleach (Liquid Chlorine) or Cal-hypo to clean up. The pool is consuming chlorine too fast to reach and maintain shock level with just dichlor.

You'll also need Borax to raise pH after dichlor lowers it. I don't know why you get such a strange reading but dichlor should push pH down.

You'll also need "The Good Test Kit" the Taylor K-2006 (or K-2006C) available from the link in Watermom's Sig. It will let you eaisly measure the high chlorine levels you'll need (from Ben's Best Guess Chart) to finish off the algae in yourn pool.

Go ahead and add one more dose of dichlor if that's all you have on hand but don't use more without getting a reliable reading on your pH.

If your test kit only goes to 5 and is reading 5, then it could mean 5 or it could mean higher than 5. Same with your pH. It could mean 8.2 or it could mean higher than that. What color is the chlorine test showing? Dark yellow, orange, ?? I am not calibrated on dichlor dosages. What did the package say in regards to how much a dose of dichlor would add to your chlorine level? I will tell you that for every 10ppm of chlorine that it adds, it also adds 9ppm of CYA.

You really need to get a better test kit. An OTO/Phenol Red kit is fine for quick daily testing, but when you are trying to clear a pool, it isn't adequate. We recommend the Taylor K-2006 or 2006C (same kit, larger quantities). You can get it through the Amazon link in my signature below. Only order if the seller listed is Amato Industries as sometimes other sellers substitute the K-2005 instead which you don't want.

To get a more accurate pH reading, retest it when the chlorine is low. Repost with new numbers and order a good kit.

I just ordered K-2006 kit. An aside, Amazon vendor was VM Innovations so I went to Amato website to order. I forgot to mention that the PH level yesterday "scared me" so I added muriatic acid. This am the PH is 7.2 and chlorine is same 5, a dark yellow. Should I go ahead and add another 37 oz of dichlor now? I used Pool Calculator to determine amount, fyi. After that, should I wait to get better test kit before doing anything else? I really want to add borates (per sticky note) when I get algae straightened out.
Thank you, thank you, thank you for all your help!!!

PS, I just subscribed to the forum. Thanks for all the help!

As you pH is 7.2, don't use any more dichlor until you can raise it with borax. I was under the impression that you had pretty much the same chlorine before and after adding the dichlor indicating a drop of 5 - 7 ppm. If your chlorine hasn't changed since yesterday, I'd wait to get accurate results with the K-2006. If you chlorine does drop to a level you can read with OTO, then I'd bring it back up to shock level with bleach.

BTW Thanks for subscribing!

So next step is to raise the pH with borax or should I wait on new test kit? If I raise the pH first, then I wait on new kit unless I can read chlorine level with current kit, right? then I would shock the pool? Will bleach be better to use than cal-hypo to shock? Should I leave filter running for now? Thanks!

I wouldn't add another dose of dichlor with the pH at 7.2 as it could push your pH below 7.0. How low does your pH comparator read?

We're not sure how high your chlorine is, just that it's above 5ppm. You need to be at 15ppm for shock level - we'll be able to measure this directly when the K-2006 arrives. If your chlorine reading looks the same today as yesterday, then it's not being consumed fast and I'd be concerned with over-dosing until it can be reliably read.

When you can get a reliable (in range) chlorine reading, you can decide to: 1) Bring pH up with borax and dose with dichlor - or - 2) Dose with bleach or cal-hypo. I would avoid cal-hypo at this point as we have no CH reading (we will when the k-2006 arrives).

To get a ballpark figure of where your chlorine is until your good kit comes, you can dilute your water sample. This is not super accurate, but better than nothing at all.

Testing Without a Good Kit

Either use bleach or dichlor but if you use dichlor, you do need to raise your pH some with Borax or it may drop below 7.0 which you don't want. Yes, to running the pump 24/7 while you are trying to clear the pool. What kind of filter do you have?

Thanks for becoming a subscriber! We appreciate the financial support!

Quote:

---

Originally Posted by BigDave

I wouldn't add another dose of dichlor with the pH at 7.2 as it could push your pH below 7.0. How low does your pH comparator read?

We're not sure how high your chlorine is, just that it's above 5ppm. You need to be at 15ppm for shock level - we'll be able to measure this directly when the K-2006 arrives. If your chlorine reading looks the same today as yesterday, then it's not being consumed fast and I'd be concerned with over-dosing until it can be reliably read.

When you can get a reliable (in range) chlorine reading, you can decide to: 1) Bring pH up with borax and dose with dichlor - or - 2) Dose with bleach or cal-hypo. I would avoid cal-hypo at this point as we have no CH reading (we will when the k-2006 arrives).

---

pH comparator goes down to 6.8. I just checked chlorine and it looks like it is still at 5. Kind of hard to tell as it is 8:20 at night so my indoor light is not as good as day light. I have a sand filter. Should I be running pump 24/7 even if I am not adding anything right now? Glad to help financially...it didn't seem right to get all this advice and assistance for free!
sorry if i replied multiple times...

While you are trying to clear the pool of algae, you should run the pump 24/7. Watch your filter pressure. When it rises 8-10 psi over your clean filter pressure, backwash it.

Morning! PH is 7.2 and chlorine is still at 5. I misspoke yesterday about the color. I would say it is a medium yellow at most and not dark. I'm planning to get distilled water this morning to do the test without a kit since I haven't heard that the 2006 kit has shipped. I am leaving town in 24 hours (Fri am) and will be back on Sunday evening. Any way to shock with bleach (based on distilled water test results) in 24 hours successfully or will I be wasting bleach?
Thanks.

Medium yellow meaning matches the color of the 5ppm on the comparator or darker than that?
A one to one dilution (shot glass method - Multiply result by 2) should give you a good idea if you're in range.
Four gallons of 6% bleach should raise your FC 11ppm which puts you at shock level if the initial is 5ppm.
A three to one dilution (Multiply result by 4) should indicate if you're at shock level.
Run the pump, brush the pool, test again this evening and bring it back to shock as necessary.
Are you planning to leave the pump running while you're gone?

Have a great trip!

Medium yellow meaning slightly darker than color of 5ppm. I just retested chlorine with kit and got about the same as before (slightly darker than 5). Then I mixed 1/4 c. distilled water and 1/4 c. pool water and tested and got 5 ppm. so if I multiply that by 2, I'm at 10. Pool calculator says to go from 10 to 15 ppm, I need to add 1 gal., 3 qts and 1 c bleach (6%, I'm clear on that). After I add bleach and scrub, how often should l check to see if I'm at shock level? Also, is 3 to 1 dilution 3 parts pool water or 3 parts distilled water? Can you see that I am getting anal...
Does this sound correct?
Sure, I can leave the pump running. Thanks, I'm off to visit my daughter and her family. My 2 ADORABLE granddaughters (ages 8 1/2 and 7) LOVE the pool and go in NO MATTER WHAT the outdoor temperature is. Sometimes they aren't in long :) They first went "naked swimming" 2 days after Christmas 4 years ago. One of the funniest thing I have ever seen...lots of squealing!
I'll have to add you to my Christmas card list after all this help :)

Quote:

---

Originally Posted by Kateyru

After I add bleach and scrub, how often should l check to see if I'm at shock level? Also, is 3 to 1 dilution 3 parts pool water or 3 parts distilled water?

---

During the process of shocking a pool, the more often you can check and bump the chlorine back up, the quicker the pool will clear--it is the consistency of shock level that will kill the algae off the quickest. Every 2-3 hours would be great, but that's not feasible for most people, so at a minimum I would say 2-3 times a day, or however often you can. Also, 3 to 1 dilution means 1 part pool water, 3 parts distilled water--the goal is to dilute the pool sample enough to produce levels that can be read by your tester. You'll love the K-2006 kit--it makes this SO much easier! :)

Janet

Today I can test frequently, yea! so will do that. can't wait for the K-2006 kit.
I just realized that different people have responded to me. THANKS TO ALL!!!!!!!!!

Yeah, we're all sorta interchangeable :)

Enjoy your visit with your grandkids :) :)

Janet

To be clear: leave the pump on only if there is no chance that your skimmer and drains won't get clogged with debris and that your filter won't get filled before your return. Otherwise, do what you can today shut it down while you're gone and go at it again when you get back.

BTW, for 1 gal., 3 qts and 1 c, I'd be inclined to put in two gallons. This is not exact.

Quote:

---

Originally Posted by BigDave

BTW, for 1 gal., 3 qts and 1 c, I'd be inclined to put in two gallons. This is not exact.

---

Yep! What he said!

We just had a nasty storm go through so I fished a branch out of the pool, emptied the skimmer basket then checked chlorine. It seems to be at 20. This is 2 hours after shocking. I think the weather is going to be fine till Sunday but, for clarification, if I thought there was a chance that skimmer and/or drains would get clogged or filter would fill, I should completely shut the pump down??? and not leave it on the timer (currently set for about 8 hours per day)?

Sorry, didn't know you had a timer. If you're comfortable having it on when you are away then by all means leave it on or on timer. The concern is that if you're away, unable to check, and something should stop the flow of water, you may end up with pump damage.

That's a little scary...I was thinking that I might "lose ground" so to speak with clearing the algae if the pump didn't run for 3 days. Is it better to just let it run or to use timer given the algae invasion?

I'm hesitant to leave mine running so long unattended. But, mostly because of all the trees around. Especially right now, the trees are dropping an incredible amount into the pool. I have so many 'helicopters' falling out of my maple trees, that if I could sell them for a nickel a piece, I'd be rich!

I got home last night, and pool looks really good! Woot, woot! No green algae, chlorine seems to be at 12 based on dilution test. Do I need to get back to shock level, i.e. 15 or just leave it alone??
Also, I think there is some dead algae in the pool...looks like whitish dust. Do I need to vacuum? Will my Dolphin robotic cleaner get it up? Can I just leave it in there? Weather has cooled down so I won't likely swim for a week or 2 so am happy to avoid the vacuum.
My new K2006 test is scheduled to arrive today.
Thanks to all of you again for all your help.

Welcome home, hope you had a great time.
Since your K-2006 is coming soon, let's do this: Let's get the pool back to shock level and mainatain that until we can get reliable and accurate reading for CYA, FC and CC (with the new kit). If you have 2 gallons of bleach on hand, put 'em in now. Start the pump and leave it running - backwash as necessary when the pressure rises 8-10 above clean. If you don't have the K-2006 by this evening, test CL by dilution again and let us know.

will do!

Just tested with my new K2006. Here are results, FC = 16, CC = .5 and CYA = 30. What's the next step...retest in the morning?

Yep, as close as possible to sunrise. You want to find out if you've lost any FC overnight. The fact that you have .5 CC is significant: it means your chlorine is getting rid of something in your pool. In the morning, if you have lost no FC and have lss that .5 CC, you'll be ready to declare victory. At this point, you'll probably have to maintain shock for another day. You are very close, keep it up. let us know your readings in the morning.

Congrats on the K-2006. I find it sooooo much eaisier than any other kit I've owned.

Do I test FC, CC and CYA again or just FC and CC?

FC and CC. No need to test CYA again for awhile and you don't want to waste that reagent.

I didn't think so but wanted to make sure! Thanks.

This morning test results: FC = 18.5 and CC < .5 Dd I need to add more bleach? If so, how much? Thanks!