OTO, Cloud, HELP!

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T

TL

0
Jun 10, 2010
14
Hello! Just joined today, and I have to say THANK YOU ALL for providing this site and the information it provides. I finally have a place I can go for information that I trust.

My problem, like so many others, is persistent cloud. Had it last year for most of the summer (i had no idea what I was doing, other than keeping Pools Plus afloat), and I am off to a bad start this year. Opened the pool last Sunday, severe white cloud. I have cleaned the pool, scrubbed, and been adding LOTS of bleach. 3 big bottles at night, during lunch, etc. I have read all of pool school and I am following the steps to beat algae. Although it is white, so isn't it dead already? I am on day 4 only, so I realize it is early in the battle. The reason I keep adding more bleach is because I may be reading my test wrong. I have an OTO test (and yes, I have a Taylor kit ordered from amazon, which won't get here until next week) and the instructions say that you add five drops and match the color at 10 seconds. This represents FREE chlorine. Then, wait more than two minutes and the color represents TOTAL chlorine. Subtract and you get the combined. So, when I have been testing, I get about 1-3 ppm at around 10 seconds. A light yellow. Then, if I go work on my pool for 20 minutes and come back, it is dark orange-brown. So, does that mean I have little/no free chlorine but tons of combined? Should I just keep blasting it with the big jugs? Below are my numbers from Tuesday, the day after I had added 6 total jugs. These are the pool place numbers, not the numbers from the OTO test. I have added lots more chlorine, and I am still getting the same OTO test results of light yellow changing to dark orange-brown over several minutes.

20,000 gallon pool, Vinyl liner, Hayward sand filter

pH- 7.6
FC- 0
TC- 7
TA- 120
CYA- 35
CH- 220

If my assumption is correct, that all my chlorine is being eaten up, it sure seems like I am adding a TON of bleach to clear out some dead algae. I have "blind vacuumed" several times, and scrubbed the walls and floor a bunch too. I believe I have most of the stuff off the bottom, but it is hard to tell. I guess I am also looking for advice on how to use the OTO test to get rid of the cloud before the better test kit arrives. We have a party 9 days from now. Thanks for your help, and sorry for the long post!
 
Welcome to TFP!

Based on your description, you appear to be interpreting the OTO test correctly. It shows FC right at first, then starts shifting to show TC eventually. Your results match with what the pool store said, so it all makes sense.

You must have a fair bit of ammonia, or something similar, that is consuming chlorine very quickly. This most commonly happens when CYA has vanished over the winter or when fertilizer gets in the pool. There are two solutions, lots and lots of chlorine, or replacing most of your water. In most cases the chlorine approach is best, but in a few rare extreme cases replacing water can be a better option.
 
Thanks for the quick response! Well, that makes me feel better about the cloud, because it must be the chlorine working on something. Here are the numbers I just got from the pool store.

pH- 8.2 (from all the bleach I've been using?)
TC- 3 ppm
FC - 3 ppm
TA - 160
TH - 130
CYA- 35

I have a bunch of questions about these numbers:
1. I tested my water using the OTO test just before I went to the pool store and had the usual result: light yellow almost immediately, going to orange-brown within 10 minutes. Yet their test says my pool has a nice 3ppm with none combined????? Makes no sense. Pool still has cloud.
2. The Alkalinity went from 120 on Tuesday, to 160 today and all I have been adding is lots of bleach, and 5 lb of Cal-hypo. Does pH going up increase Alkalinity? Would the Cal-Hypo?
3. Total hardness went from 217 on Tuesday, to 130 today. Would the above additions and pH rise account for this big drop in hardness?
4. Is total hardness the same as calcium hardness?


My plan is to drop the pH down with MA, and that should bring the TA down and help the chlorine work. And I will continue to test using the OTO test and base my chlorine addition on the results obtained in the first 10 seconds, no longer.
Thanks again for all your help!
 
1) No, that makes no sense. Someone is wrong, most likely the pool store.
2) TA goes up when PH goes up, so that is normal. Lower your PH and the TA will go back down.
3) Not possible, one of the test results is wrong. Again, I suspect the pool store.
4) No, total hardness includes magnesium and a few other things. Usually about 2/3rds of total hardness is calcium but that varies.

Good plan.

This is another example why we say that it is so important to have your own high quality test kit.
 
Jason- thanks a ton for helping me out and for taking the time to answer my questions! One last set and I will leave you alone for a while :)

I have also been using the phenol red test for pH, and I thought that it was a faint orange color, which is in the proper range. I got the 7.6 value from the store on Tuesday, and like I said, today they say it is 8.2. I got home, and after reading your response about the pool store being wrong, I checked the pH with my fresh phenol red and I swore, along with my wife, that it was a pH of around 7.2. But, I did the stupid thing, trusted the store, and went ahead and added the MA I bought to bring down the pH. Went for a run. Came home, and rechecked the pH and now it is a light orange or maybe even slightly yellow. I think they screwed up their pH reading too, and they just had me bring my pH from somewhere in the 7's to somewhere in the 6's. Is it possible that the store could be so wrong on so many tests? It definitely was not a bright magenta, which is what the pH kit says it should be to be at a pH of 8.2. What would you do in this situation? Bring it up with borax, or aerate to get it up? Leave it and let the constant additions of bleach (being used to clear cloud, which is improving) bring it up slowly? I now officially hate the pool store. Thanks again for your help and recommendations.

tony
 
That raises an interesting question: IF lower pH helps chlorine do its job better, and I am trying to clear a clouded pool, what is the lowest pH that you should hit to maximize chlorine effectiveness safely? Things to consider before answering:

vinyl liner
no ladder or metallic objects in the pool
just the liner and the pump parts exposed to the water
sand filter (hayward)
nobody swimming
no animals either!
 

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OK, I got my new Taylor k-2006, and just tested my water. Currently the appearance is still cloudy, but improving (slowly, if at all). Last night, my wife and I added 6 big jugs of clorox, which according to the poolcalculator added about 26 ppm free chlorine. Here are the results:

FC - 0.4 ppm
CC- 5.8 ppm
pH- 6.5 (approximate, it was yellow and required 22 drops for the base demand test to get the pH to 7.3)
TA - 90 ppm
CH- 140 ppm
CYA - none detected, black dot clearly visible when chamber was full. I know there is some in there because I have burned through about 7-8 Trichlor 3" tabs since we opened, and we used them all last summer as well. Pool store said 26 last week.

My first question is regarding the test results. When I did my TC/FC test, I titrated until the pink color went away, but for both the FC and CC portion of the test, about a minute after the perceived endpoint, the pink returned. Is this typical of this test? I added one more drop for the FC test and the pink went away, but for the CC, the pink came back with a vengeance and after adding 5 drops just to see if it got rid of the pink I quit, assuming the original endpoint was correct. I was constantly swirling, so mixing was not the issue. I know that for both, they went completely colorless. It simply returned after a significant delay. Is this due to CO2 dissolving and bringing down the pH?

My next question is what your recommendations are, assuming my numbers are correct. Get the pH up using borax first, then calcium up, then SUPERDUPERHYPER chlorinate tonight? Taylor recommends super chlorinating when there is CC present at levels higher than 0.5 ppm. They say you go 10X the free chlorine, which would be about 60 ppm for my pool, and around 13-14 jugs (182 ounces) of bleach. What is the best way and order to attack things?

Thanks a ton!
 
Fix the PH first. Ignore the CH for now. Deal with CH once everything is completely back in balance.

I would not "SUPERDUPERHYPER chlorinate" with a vinyl liner. Follow the directions on How to Shock Your Pool at Pool School. That whole x10 rule is simply wrong.

Yes, the pink returns if you leave the solution alone for a minute when doing the FAS-DPD chlorine test. That is completely normal and can be ignored.

You should bring your CYA level up a bit more when you have a chance, something around 40 would be good.
 
Thanks! Ok, I added the correct amount of borax and I will retest in a couple hours. After I added the borax, I waited 10 minutes or so (watched the end of the soccer game!) and then re-read the "how to shock your pool" article in pool school. I went back outside, and added 3 jugs of clorox, which is the appropriate amount to shock my pool to get it up the correct FC level. I brushed the whole pool and skimmed all debris (not much) which took about 15-20 minutes. I then checked my chlorine levels using the FAS-DPD test in my Taylor kit, and here is what it said:

FC- 0.8 ppm
CC- 2 ppm

Is it possible that all the chlorine I added, 15 minutes before, was eaten up already? Is it a good thing that my CC came down from about 6 at noon to about 2 after this latest addition of clorox? Side note, it appears that the cloud is improving, I think you suggestions are bearing fruit! Thanks again! Rather than assume my FC is already down that far, I am going to go for a run and retest and check for your reply/advice. If at that point the FC is still low, I will add 3 more jugs and continue to retest/shock per pool school article. Also:

Should I add stabilizer or just continue to use the pucks I bought until the right level is established? (I go through about 7 a week when running the pump 24/7 on setting 5, which is what I am doing trying to get rid of the cloud)
 
After only 15 minutes it is possible that the chlorine had not mixed throughly and you were testing some water that hadn't been exposed to the chlorine you just added. Of course it is also possible that the chlorine all got used up in 15 minutes.
 
TL,

Yoy are on the right track. It is a very good thing that your CC's are reduced, maybe even lending more creedence to the idea that your FC was used that fast.

Regardless, stay with that article, test and clean frequently and dose with more chlorine as often as it's called for. You will use less and less (FC) and it will deplete slower and slower as time goes on. Just keep it up. you're on your way to a crystal clear pool.

I would add enough stabilizer to get the pool to around 20-30ppm to help your FC hold during the day. I wouldn't use the pucks at all since they dissolve so slowly you will never get a significant CYA increase during this process. Save them for vacations, etc.

Don't stop the process until your water is crystalo clear. This works but you have to stay with it understanding it will take many, many additions of FC.
 
Thanks for the advice duraleigh! I just got back from my run, and my free chlorine was 0.2 ppm, and combined was 0.8. My pH, after adding 20 lbs of borax and waiting 2 hours, had crept up to about 7. So, I added clorox to shock levels again, added some more borax, and we'll see where it's at in an hour. You recommend adding stabilizer, but isn't it true that I don't really know how much I have in there because the CYA that has dissolved into the pool since we opened (8 pucks or so of trichlor, over the last 5 days) might not show up on the test yet? I could have 20-30 ppm in there already, and the pool store said I had 28 ppm the day after opening (4 days ago). Also, since I am intrigued about running a borate pool, so should I be keeping track of how much borax I have used to raise my pH? Thanks!
 
If you look at the bottom of the pool calculator, there is a section for effects of adding chemicals. A 3" puck weighs 8 ounces. Thus a 3" puck raises CYA by3.2, FC by 5.3, and lowers pH by .28. So for 8 pucks would have raised your CYA by 26, assuming you do not have an ammonia problem that is eating the CYA. It also lowered the pH by 2.26, since you are trying to get the pH up you need to retire the pucks for awhile. Stick with bleach or liquid chlorine and add enough stabilizer to get you from 26 to 35 and see how it goes. You CYA is probably still too low to prevent your chlorine from burning off prematurely.

You can go to the effects of adding chemicals section of the pool calculator to see how high your borates should be according to how much you have added so far.
 
zea3,

Your math may have an error. I don't think 8 pucks can raise CYA by 26 in a 20k pool. I am late and need to get out of here but recheck that.

PS - it will not be the first time I have been wrong but that just doesn't "seem" correct.
 
Thanks for the help zea, but I believe your calcs were based on a 10000 gallon pool, so cut those in half for mine. I am going to get some stabilizer tomorrow morning and get that dissolving. I just checked my numbers after the recent addition of chlorine, and my FC was 4.2 and CC was 0.4. Although it is getting darker out now, I think the cloud may be improving. I added 2 jugs of clorox to spike it back up to shock levels, and I will recheck in an hour. I did have a couple other questions that I thought of:

1. Does FC just kill the algae, or will it, given time, destroy the entire body of the algae? The reason I ask is because if we assume this white cloud is from dead algae (which it has to be right?) then the chlorine is working on destroying the body of the algae, not killing it, right?

2. After adding 24 lbs. of borax, my pH is still around 7. Any tips on reading a pH test? Does it take a while for the pH to adjust after adding borax?

3. Any good ways to aerate a pool if your eyelets don't really allow you to shoot water out of the pool and you don't have any fancy equipment or fountains? I do have a 1 horse shop vac.

Thanks everyone!!!
 
Ok, checked it after the last addition of clorox, down to 6ppm FC and 1ppm CC. So, because it's night, I added 4 jugs and called it a night. Based on the pool calculator, that should take it from 6 ppm FC to around 24. I am assuming the chlorine consumption continues so I exceeded the shock amount for the night. Hope to see improvement in the morning.
 

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