More Cloudy Water

[speedjunkie]

Newb here, found this site trying to figure out my water clarity problem. I've been dealing with cloudy water for about 3 weeks now. It's MUCH better, but still doesn't sparkle. My local PS has done a good job of taking my money, but not helping correct the problem.

It's 21,400 gallon (per pool calculator) in ground vinyl pool. It started about 3 weeks ago. It went a couple days without checking the Zeo filter pressure, and I come out and it's pretty well plugged. Very little circulation, starting to smell, looks green. FC was 0. Oops!

I backflushed, added 1 qt Algeacide 60, and 5 pounds of Ca Cl. Clouded right up, and it's been that way ever since. But the green was gone. I expected it to cloud up with the Ca Cl, but not to stay like this.

Over the last 3 weeks, I've added an additional 16 oz of Algeacide, a quart of clarifier, Pool MD (or something like that from Leslies), 4 pounds of oxidizer, 1 gallon of MA, and 8 pounds of Dichlor, plus stabilized tabs, and even replaced the Zeo sand. All but the Dichlor and tabs have been at Leslies suggestion. I even tried the polyfiber stuff for the filter, and that didn't help that I can tell.

I'm pretty well fed up with Leslies at this point. They always showed equal FC and TC while I could never get the same FC readings they get, so I thought maybe my DPD kit reagents were bad. Bought new from them. Tried again, same result. So, I watched him closely the other day and he's putting in more drops than the instructions say to. Now, per my little test, I can fudge the results too if I add too much reagent 001 and 002. Not to mention, I watched him only use reagents 001 and 002, then just write down 5 for the TC. My kit says you have to use 003 for the TC.

Now I'm somewhere between mad and confused. Am I doing the test right? I think so. Are they doing it wrong? I think so, and why? So, now it's time to do this myself.

As of yesterday,

FC 2.0

TC 5.0

TA 200

pH 7.0

Now, my plan is to add about 6 gallons of 6% Walmart bleach to try and get rid of the CC. Then raise the pH with aereation and MA to lower the TA. Does this sound right? It holds FC, it's just the CC that I don't like. I feel this is the major problem with my clarity. Thoughts?

Any and all advise is greatly appreciated! Thanks in advance!

Mike

[chem geek]

Mike,

You didn't show your Calcium Hardness (CH) and I'm not sure why you added 5 pounds of Calcium Chloride (about 25 ppm CH in your 21,400 gallon pool if the calcium chloride was anhydrous and not dihydrate). In a vinyl pool, you don't need to worry about Calcium Hardness and it can be low -- around 125 ppm if you want to avoid possible foaming.

You also didn't show the Cyanuric Acid (CYA) level and it will be difficult to know how much you need to shock (for reasonable clearing time).

As for the chlorine test, you are only measuring Free Chlorine (FC) if you only add R-0001 and R-0002 in the DPD test. You get a Total Chlorine (TC) reading if you then add R-0003. They are doing the test wrong if they put in more drops than you are supposed to since more drops of reagent can result in a darker reading that is artificially high due to excess of R-0001 (phosphate buffer) and especially R-0002 (DPD indicator dye). The comparator tube color intensities are calibrated assuming the tests are done correctly with the amount of reagents (i.e. 5 drops each) given in the instructions.

The pool is most likely cloudy because you didn't completely get rid of the algae. Algae turns from green to gray when chlorine oxidizes the chlorophyll, but more chlorine is needed to oxidize the rest of the algae. See this link for how a pool gets cleared of algae using chlorine alone and notice that after it is green, it turns cloudy and takes some time to clear.

Read and follow the instructions in Defeating Algae. Also, get yourself a better test kit: either the Taylor K-2006 you can get at a good online price here or the TF100 you can get at tftestkits.net here. Take charge of your pool.

Richard

[speedjunkie]

Richard,

Wow, some of that was Greek, sorry. But I'll educate myself, so no worries!

I added the Ca Cl because that's what I had at the time, might have been a mistake.

I'll also get the water checked for CYA, but I know it's around 30 IIRC, I did add stabilizer too, I may have forgotten to mention that.

I have one of these kits. If I need to get the better one, I most certainly will.

I think the pool store is using the more expensive kit. If the Cl tube is the same between the 2 kits, then they definitely did the test wrong, not to mention didn't add the -0003 to get the TC.

I will research the algea more thoroughly, but I don't think that's the issue.

BTW, the pool school is great! Thanks!

Mike

[chem geek]

I added the Ca Cl because that's what I had at the time, might have been a mistake.

I'll also get the water checked for CYA, but I know it's around 30 IIRC, I did add stabilizer too, I may have forgotten to mention that.

I have one of these kits. If I need to get the better one, I most certainly will.

Mike,

I think you may have meant that you had Cal-Hypo which is a form of chlorine, not Calcium Chloride which is used to raise Calcium Hardness (CH). With hard water, Cal-Hypo (CH) can make the water cloudy. Your test kit is almost perfect, but could use a FAS-DPD chlorine test so that you can test chlorine more accurately and test higher shock levels. I suggest you just supplement with just the FAS-DPD chlorine test kit from tftestkit.net here.

If the CYA is truly only 30 ppm and you've shocked with chlorine, then it does sound like your water got over-saturated with calcium carbonate. Use The Pool Calculator to enter your current numbers and see if the saturation index is significantly > 0. That would account for the cloudiness. To lower the Calcium Hardness (CH), you'd have to dilute the water if your fill water was lower in CH (so you should test your fill water).

Richard

[speedjunkie]

I think you may have meant that you had Cal-Hypo which is a form of chlorine, not Calcium Chloride which is used to raise Calcium Hardness (CH). With hard water, Cal-Hypo (CH) can make the water cloudy. Your test kit is almost perfect, but could use a FAS-DPD chlorine test so that you can test chlorine more accurately and test higher shock levels. I suggest you just supplement with just the FAS-DPD chlorine test kit from tftestkit.net here.

If the CYA is truly only 30 ppm and you've shocked with chlorine, then it does sound like your water got over-saturated with calcium carbonate. Use The Pool Calculator to enter your current numbers and see if the saturation index is significantly > 0. That would account for the cloudiness. To lower the Calcium Hardness (CH), you'd have to dilute the water if your fill water was lower in CH (so you should test your fill water).

Richard

Richard,

Yes, I did meant Cal-Hypo in the shock, sorry.

My current test kit doesn't do CYA or CH, so I need to get something to do that too.

I aereated and added a little bleach today since things were a little low. This afternoon:

FC 2.0

TC 5.0+

TA 240

ph 7.2

It will be Wednesday before I can get a kit that will take care of the CYA and CH, so I'll fill in the blanks then. I'll also see if I can get one of the FAS DPD kits to test for higher chlorine levels. That's alot easier than diluting with bottled H2O.

Thanks to you, I'm feeling pretty good about the pool again!

Mike

[chem geek]

Mike,

By any chance are you using non-chlorine shock (potassium monopersulfate, MPS)? If so, then it can falsely read as Combined Chlorine (CC).

Richard

[speedjunkie]

Mike,

By any chance are you using non-chlorine shock (potassium monopersulfate, MPS)? If so, then it can falsely read as Combined Chlorine (CC).

Richard

I put in 4 pounds of MPS about 2 weeks ago per Leslies, in the hopes of freeing up the FC. I had a high CC reading before the MPS, and still have it. The CC hasn't changed with the use of the MPS as near as I can tell.

Mike

[speedjunkie]

So, I got the good Taylor kit today and checked the water.

FC=1.5

TC=5+

pH=7.0

TA=230

CH=400

CYA=60

Ammonia=3

The FC is a little low as I've had to add water. Looks like I have a leak! I've been adding city water, not well water.

So, I'll aereate this afternoon and MA to bring the TA down. Now, as I understand it, the only way to bring the CH and CYA down is to pump water out, and fresh in, correct?

Gotta try and find the leak first, it all may be for nothing. My pipes are under concrete, so there's no way of knowing if the leak is there. Any tips on this little problem? I notice a little air sound coming from the pool sweep. So, I shut it off, turned off the valve, and capped it off at the pool. We'll see if that's the culprit.

Thanks again!

Mike

[chem geek]

I don't know about your leak, but you've got a lot of Combined Chlorine (CC). You say you got the good Taylor test kit today, but the Taylor K-2006 has a FAS-DPD chlorine test that would let you accurately measure the Combined Chlorine -- it wouldn't just be 5+. The ammonia test actually measures the sum of ammonia and monochloramine so 3 ppm ammonia is equivalent to 15 ppm monochloramine (measured as ppm Cl₂ as with all chlorine measurements). So, you need to shock the pool with chlorine to get rid of this. Just raise the FC level to around 25 ppm and hold it there until the FC and TC in your test kit become the same. This will probably only take a few hours, perhaps a day. The FC will drop quite a bit -- just keep adding more until the FC and TC match and the FC no longer drops overnight.

I suspect that at some point your FC got to zero and bacteria converted some of your Cyanuric Acid (CYA) to ammonia. You've since added chlorine to that which makes Combined Chlorine (CC) and that's where you are at now. More chlorine will get rid of this CC.

[speedjunkie]

I don't know about your leak, but you've got a lot of Combined Chlorine (CC). You say you got the good Taylor test kit today, but the Taylor K-2006 has a FAS-DPD chlorine test that would let you accurately measure the Combined Chlorine -- it wouldn't just be 5+. The ammonia test actually measures the sum of ammonia and monochloramine so 3 ppm ammonia is equivalent to 15 ppm monochloramine (measured as ppm Cl₂ as with all chlorine measurements). So, you need to shock the pool with chlorine to get rid of this. Just raise the FC level to around 25 ppm and hold it there until the FC and TC in your test kit become the same. This will probably only take a few hours, perhaps a day. The FC will drop quite a bit -- just keep adding more until the FC and TC match and the FC no longer drops overnight.

I suspect that at some point your FC got to zero and bacteria converted some of your Cyanuric Acid (CYA) to ammonia. You've since added chlorine to that which makes Combined Chlorine (CC) and that's where you are at now. More chlorine will get rid of this CC.

You're right, no FAS. I checked 2 different pool stores. Leslies was the only one that had a kit that would check the CH and CYA. I think the other store had FAS refills tho. I don't see anything in the 2600 kit that I'm missing except for the FAS, is the correct?

I wasn't even having any luck finding someone in town with the high percentage Cl, so I bought 4 more big jugs of bleach. I'll check with the pool calc and see how much I need to 25. I should have enough on hand to get there, but will likely need more to maintain it.

Thanks Richard!

Mike

[chem geek]

Leslie's does have a Chlorine FAS-DPD Service Test Kit, but that may only be available online. A much better price for it is found here. Yes, all you are missing is the FAS-DPD chlorine part of it. If you wanted just that part, you can get it at tftestkits.net here.

[speedjunkie]

Thanks Richard. I'll check with Ultra Modern, but I'll likely just get the supplement kit.

Gotta figure out my leak first tho.

Mike

[speedjunkie]

Richard,

I received my FAS kit today from Duraleigh, good stuff! Per the test kit

FC=.5

CC=1.5

So, it doesn't look like my CC is as bad as I thought, weird. The water is pretty clear, but the FC still drops off over 2 to 3 days, but then again, I'm not hitting it super hard either. Wonder if I still have something growing, even tho the pool isn't green? I'll shock it this weekend tho and get rid of the CC. Might even kill whatever is still there, I hope.

Another odd thing. I've used the pool calculator, but I don't seem to get the same FC levels that it says I should see after adding bleach. I'm using the large jugs (182 oz) from Wally (6%), and don't get a FC rise of more than 1.5 to 2 ppm. Per the calculator, I should be getting 4ppm with a full jug. Any thoughts on this?

Thanks again!

Mike

[speedjunkie]

Ok, so I started with .5 FC, I added 5 182oz jugs of 6%. Per the Pool Calc, that should have brought my FC to 21. Now, it's been about an hour since I added it, but if I let the FC test set for a few seconds, and continue to add drops, I'm up to about 7 on the FC. Do I add drops until it goes clear the first time? Or when it turns pink again, keep adding until it doesn't turn anymore? For now, I'm going back out to add another 4 jugs. See if I can keep the FC way up there. Any advice would be appreciated!

Mike

[chem geek]

If there is CC, then there can be some "bleed through" into the FC portion of the test (this also can happen with high non-chlorine shock, MPS, levels). I'd do the FC test in a reasonably fast fashion with swirling and don't let it settle -- when it first becomes clear and stays clear for at least a few seconds, you are done. If you let it sit and it starts to go pink again, that's probably CC bleeding through.

If you've got something consuming chlorine in your pool, then that could account for the difference in what you think you are adding vs. what you actually get. You could verify the chlorine strength by adding 1/4 teaspoon of 6% bleach in a 2 gallon bucket (make sure it's really clean first and thoroughly rinsed) which should measure 10 ppm FC. If it's significantly less, then your bleach may not be as strong as you think.

[speedjunkie]

Robert,

Per your advice, I took 2 gallons of pool water and added 1/4 teaspoon of bleach. Not much change, so I continued to add bleach. When I got to a full teaspoon, I read 12ppm FC. So, what was already in the bucket, 2ppm, to get a +10 was full teaspoon. So, it looks like the strength is actually 1.5%. Jeez, no wonder it's taking so much and I'm not getting anywhere! So much for Wally store brand bleach. Guess it's time to spend the extra coin on Clorox.

I think you are correct on the CC bleed thru as well. When I got the FC up to 12, it took a long time for it to barely start to turn a light pink again.

I'm also going to let the 2 gallons sit over night and see what it reads in the AM.

What do you think about Lithium shock? It's pretty potent and wouldn't need nearly as much of it.

Thanks again!

Mike

[chem geek]

Mike,

(It's Richard, but I do have a brother named Robert).

Off-brand regular bleach is typically 3% or less. You had said it was 6% so that's what I had initially assumed, but generally speaking only Clorox Regular and off-brand Ultra bleaches are 6%. Clorox Regular has the least amount of "excess lye" in it (it's pH is 11.4) so has essentially no net pH rise after accounting for chlorine usage/consumption. With off-brand Ultra bleaches (with typical pH of 12.5), the pH will rise by 0.1 every 2-4 weeks depending on chlorine usage rates.

Lithium hypochlorite is the most expensive source of chlorine you can buy by far. You need to look at prices per FC delivered, not the % Available Chlorine by itself. Trichlor is the most concentrated form of chlorine at 90%, but per pound it's far more expensive than bleach or chlorinating liquid. Yes, with bleach or chlorinating liquid you are paying for water, but it's cheap per pound. Again, it's the price per FC that is relevant unless carrying the chlorine (i.e. its weight) is a big factor for you. A cost comparison of chlorine sources is shown in this post.

Richard

[speedjunkie]

Richard,

I'll get it right one of these days!

I stopped by Leslies last night and just talked to the kid. He was wondering if something like copper was eating up the chlorine. So, I took a sample in today. This is per them.

FC=2.0

TC=5+

CC=3+

pH=7.7

TA=160

CH=250

CYA=40

TDS=1600

Copper=0

Iron=0

Well, there went the theory on the copper. So, I knew my ammonia was still high at 3, so I took a chance and bought 5 pounds of MPS. Dumped it all in. I just took a few readings after 3 hours or so.

FC=2

TC=2

CC=0

Ammonia=0.5

Right now, I'm pretty happy. It's about bloody time! The CC is 0, and it's actually held FC for over 24 hours. I'll hit it with some more chlorine tonight just for good measure tho, bring the FC up to 5 or so. I'll also add a little MA to bring the pH and TA down.

I also bought a jug of Clorox brand bleach today. Now that stuff is 6%+! I checked it per your instructions. In soft water, it raised it 15ppm. In pool water, it raised it 7ppm. I figure with the fairly high CYA, that's why only 7ppm.

The crappy thing is, I checked the generic bleach, it said 6% right on the bottle. That's why I assumed it was right too!

Glad things finally turned around, I was about to call it quits and fill the pool with dirt!

Richard, I want to thank you again for all your help! You ever get to Wichita, I owe you beverage of your choice!

Thanks again!

Mike

[chem geek]

I stopped by Leslies last night and just talked to the kid. He was wondering if something like copper was eating up the chlorine.

:

So, I knew my ammonia was still high at 3, so I took a chance and bought 5 pounds of MPS.

:

I also bought a jug of Clorox brand bleach today. Now that stuff is 6%+! I checked it per your instructions. In soft water, it raised it 15ppm. In pool water, it raised it 7ppm. I figure with the fairly high CYA, that's why only 7ppm.

The crappy thing is, I checked the generic bleach, it said 6% right on the bottle. That's why I assumed it was right too!

Copper will not eat up chlorine; that's just a bunch of bunk.

MPS certainly will oxidize ammonia, but so would chlorine and it would have been far cheaper. It would, however, take a bit longer for the chlorine (about an hour at hotter spa temperatures; a few hours at pool temperatures).

As for the Clorox in pool water, the pool water must have either had some chlorine demand or it wasn't thoroughly mixed before you measured it. It has nothing to do with the CYA in the water. The FC test measures all of the chlorine including that bound to CYA since the chlorine gets released from CYA in the time of the test (it gets released in seconds as the chlorine gets used up reacting with the dye or FAS reagent).

I'm glad things finally worked out for you. Sounds like the generic bleach wasn't as strong as they claimed (assuming your bucket test showed it to be weak).

[speedjunkie]

Richard,

Thanks again, I assumed the CYA would have an effect on it, since it takes more chlorine the higher the CYA levels are, my bad.

I didn't actually test the generic bleach in tap water like I did the Clorox, just pool water. And it too a whole teaspoon to register 10ppm rise of the generic, where as the Clorox a 1/4 teaspoon registered 7ppm rise.

Thanks again, it's Clorox brand only from now on!

Mike