Thanks To All!! Clear Pool At Last

[karenkr]

First I want to thank all of you-----I finally have a beautiful clear pool. Had my doubts but kept plugging away with the bleach and just like you promised I finally have a Swimming Pool again.
Do have a couple of questions though. Even after draining my pool about 1/2 way I still have a high CYA of 120. I know I should drain again but Im going to try to just maintain a higher chlorine level for right now.
Pool readings: Chlorine: 10
Ph: 7.8 (is this too high)
TA: 160
CYA: 120
Are my readings ok???
Also have a really dumb question. Will calcium hypochlorite raise my cya?? The reason Im asking is our ACE store has a good sale on it and right now it is cheaper than bleach----but I do not want to raise my cya. The package reads calcium hypochlorite 62.4%, other ingredients 37.6% , Available chlorine 60%. Would it be ok to use or should I just stick to bleach?
Again THANK YOU!!
Karen

[aylad]

Cal Hypo will not raise your CYA, so if your Calcium readings are low, it would be a good alternative for you for now. You don't give a calcium (hardness) reading, though--you don't want to go above about 400 because you'll start hving cloudy water problems, especially with the pH and alk that high. (Hardness issues aside, pH of 7.8 is on the high end, but it's okay--same with alk of 160...........it's not okay if you have high calcium levels, though, because the calcium will tend to precipitate out of the water and cause milky looking pool.)

Janet

[karenkr]

Thanks for answering me.
I tried to test my hardness. Put 5 drops in and nothing happened. Did not turn red. Went ahead and added 30 drops of titrant and still no color. Does that mean I have too much hardness or none? If too much what do I do?
Thank you
Karen

[aylad]

Sounds like you don't have any....cal-hypo shouldn't be a problem for you.

Janet

[karenkr]

Thanks
Sure appreciate your quick answer. Should I try to lower my ph some? re-tested ph 7.8, TA 160, Cl 8
Karen

[chem geek]

You can try, but you may find that your pH will want to drift upward because of your high TA. My guess is that you'll have a hard time getting much below 7.5 and staying there without fighting a rising pH (and adding acid to compensate). There isn't a real problem operating at the higher pH you are at though your chlorine effectiveness is slightly reduced (not that much though, due to your CYA).

Speaking of CYA, your CYA is too high at 120. Yes, you can try and maintain a minimum chlorine level of 8, but if you pool is exposed to sunlight, then you'll be fighting loss of chlorine every day. I know you said you already drained by half and wanted to try and keep the chlorine level up, but if you find that you have a hard time doing that (because your chlorine loss is high and you are adding lots of chlorine every day), then read on.

My suggestion would be to partially drain and refill your pool water (again). This will lower the values of all of your pool chemicals including CYA and TA unless your fill water is high in TA (i.e. is very hard water). You can use your test kit to test your fill water, mostly for TA and CH (there shouldn't be any CYA in it). Since there wasn't any CH in your pool, I would guess there is no CH in your fill water and usually that would mean your TA in this fill water would also be low (which is all good).

Anyway, that's my two cents...for what it's worth.

Richard

[karenkr]

Thanks for the info.
Had thought about draining some of the water but right now we are on a water ban. I live in Oklahoma and this is the driest year we have had in a long time. I can get by on adding small amounts of water but not enough to re-fill. So for right now I have to contend with the high CYA. Next year will be different though-----------no more tablets for me!!!!!
Question: Since no hardness shows up should I do something about that? Do I need to add something?
Thanks for the help.
Karen

[chem geek]

Karen,

Is your pool plaster or does it have exposed grout anywhere (on a tile line, for example) or is it a vinyl lined or fiberglass pool? If it's a plaster or exposed grout pool, then you definitely have to have calcium in it, otherwise your pool water will slowly dissolve your plaster and grout. If it's vinyl or fiberglass, then you don't need the calcium.

By the way, if your pool is plaster or has exposed grout, then any dissolving of the plaster or grout would result in your pH and alkalinity increasing over time just as if you were adding soda ash (calcium carbonate) to your pool. Since you have high pH and alkalinity, perhaps this is what was happening with you (which wouldn't be good -- if your pool surface is plaster, does it look pitted or has it been getting rougher over time?).

Richard

[karenkr]

My pool is gunite--is that the same as plaster? The pool is an older one, I would say 15 plus years. We were told earlier in the season by my ex-pool guy that we needed new gunite at about $6000 --cant afford that at this time so we are making do with what we have. There is some pitting-nothing bad that I can tell though. What is wierd though is that if I check with strips it shows my hardness at 400, but with the drop kit the water does not even turn red.
Just re-tested my hardness with drops(added cal-hypo last night) and the water turned a very light shade of pink. After 40 drops of titrant the water turned a very light turquoise blue. So now maybe I have some hardness? When I add the 5 drops it sinks to the bottom and I have to stir to mix--is this ok?
Thanks
Karen

[chem geek]

Yes, gunite is technically sprayed concrete, but the calcium carbonate that we are concerned with is part of Portland cement that is part of concrete, mortar and most grout. So I've been loosely saying plaster/grout when I should really be saying shotcrete/gunite/concrete/mortar/grout/plaster (what a mouthful!). Technically, a pure plaster (not concrete plaster) is calcium sulfate (usually derived from gypsum) which also needs calcium for equilibrium, but sulfate as well (at any rate, this kind of pure plaster isn't in pools -- only concrete plaster is). But I digress...

My understanding of typical in-ground pool construction (and my understanding is quite limited) is that they dig a hole in the ground, place rebar, spray with gunite (actually spray concrete in a mixing technique that has this named gunite) and then finish with a concrete plaster surface with some tile at the top that has grout in between. So technically, the sprayed concrete (gunite) and the concrete plaster on top of it as well as the grout between the tiles contain calcium carbonate. So yes, your pool needs calcium (and carbonate, which is most of your TA) in the water.

As for your calcium test, I don't have the Taylor guide booklet with me, but I do recall it saying something about certain substances interfering with the calcium test, but I don't recall what it is. Perhaps someone else out there on this forum knows what can "bleach out" the calcium test. At any rate, it does appear that you have calcium in your pool and yes, in my experience the deep red drops usually sink to the bottom so you have to mix (shake) to get the pinkish color. If you are doing the test I believe you are, then the 40 drops means 400 ppm calcium hardness which would normally be OK except that you also have high TA (160) and high pH (7.8). That combination in theory gets you close to scaling (precipitating) calcium carbonate though I've learned that this often doesn't happen and you would likely see your water get cloudy first.

At any rate, we've already talked about you doing a partial drain and refill to try to lower both your CYA and your TA and this will also lower your CH as well, so that's really the easiest way to get down to better numbers. After that is done, then you can repost your results and we can see what else needs to be done, if anything. It may be that you will need to get your TA down even more (to 80-100), but work on one thing at a time (i.e. partial drain and refill first) or else you'll go nuts trying to simultaneously get it all right!

[EDIT] WHOOPS! Reread your post about the water ban. OK, here's what you can do instead. Follow Ben's procedure for lowering TA (http://www.poolforum.com/pf2/showthread.php?t=191) by first lowering pH (by adding acid) and then aerating. By significantly lowering your TA to 100, you should be able to have your pH remain somewhat stable at 7.5 and this combination will be better for you given your CH of 400 (it should also have pH rise less and have you adding less acid). With your high CYA, you will need to keep your chlorine up according to Ben's Best Guess CYA chart (http://www.poolforum.com/pf2/showthread.php?t=365), but you'll have to live with that (and adding chlorine regularly) until you are able to partially drain and refill your pool again.[END-EDIT]

Richard

[karenkr]

Thanks
I have some PH Minus left over from the beginning of the summer. Would it be ok to use it. States on side of bottle use 16 oz--thought I would start with 8oz and go from there. or should I buy some acid?
I have been maintaining my cl level about 8 (per chart) and right now my pool is crystal clear. The grandkids do say that it stings the eyes a little if they are in for quite awhile. I am assuming that this is because of the high chlorine level--correct?
Sure appreciate your help and PATIENCE that you have shown me
Karen

[chem geek]

No problem -- we're all here to help each other.

Can you see what it says the active ingredient is in the pH Minus? It might be Sodium Bisulfate which will add sulfate to your pool. Though that's not the best thing in the world, the amount is rather small since you won't use this all the time so I think it's OK to use this stuff and then in the future use Muriatic Acid (which is a liquid). However, Ben's technique for lowering TA usually takes quite a lot of acid, both for the initial lowering and for the continual adding and testing during aeration, so you might be better off getting the Muriatic Acid anyway.

I doubt that the high chlolrine level is causing the stinging of the eyes since you've got so much CYA to "hide" the disinfecting chlorine. Usually it isn't free chlorine that stings anyway -- it's usually a pH that is too low (maybe also if it's too high though I haven't heard that before) or its combined chlorine (CC). Your pH is a bit on the high side so that might be it, but it is possible of course that the chlorine levels are causing this (from the "bound" chlorine to CYA) and I'm just wrong.

Richard

[waterbear]

If your plaster is bad I would stay away from the dry acid....both sulfates and high cya levels have been implicated in pitting of plaster finishes in pools.
What hardness test are you using? It seems like you are either using the Taylor test or Ben's....there are 3 reagents in this test. If you are using a test that only uses 2 reagents then most likely it is testing total hardness and not calcium hardness.
Also, what brand of cal hypo is your ace hardware selling? Our store has the HTH on sale and it is only 48%

[karenkr]

If I dont use acid what should I use(if anything) to lower my ph and TA? My test kit is the one from Walmarts. I read on there that the total hardness test is the measurement of calcium and magnesium carbonate in the pool. Am I testing for the wrong thing????
The brand of cal hypo is HTH and the bag says Super Shock with chlorine at 60%. Its on sale for 2.50 a bag, the gallon of bleach at 10% is on sale for 2.59 for a gallon. Is it still alright if I use the super shock?
Waterbear: you said the acid might harm my pool---what about the PH Minus? Ingredients state Sodium Bisulfate 92% and inert ingredients 8%.
Sorry I am so dumb about these things, it seems like I think I get things straight in my mind then something else pops up and CONFUSION sets in---maybe its an age thing(HA HA)
Anyway thanks for your help and PLEASE dont give up on me.
Karen

[chem geek]

You can use Muriatic Acid which is a liquid that you can pour slowly into your pool near a water return outlet so that will mix the acid quickly with your pool water to prevent damage to the plaster. I didn't know about the problems Evan (waterbear) mentioned about using dry acid, but it makes sense and fortunately Muriatic Acid is the best alternative. There isn't any other way to lower pH other than adding acid.

As for the test kit question, I'll leave that to waterbear since I am not familiar with the Walmart kit(s). If the test kit says it measures Total Hardness (which is Magnesium and Calcium) then that is not what is important to measure -- it is Calcium Hardness that you want to measure. Typically, Calcium is the larger component of hardness so if your total hardness was 400 then your calcium hardness might be 300, but you really need to do the right test to know for certain.

The Sodium Bisulfate is dry acid that waterbear is talking about so based on what he said, don't use that and instead get the Muriatic Acid which is a liquid that typically comes in a quart plastic bottle. [EDIT] I meant "gallon jugs" just like waterbear said below. It's getting late... [END-EDIT]

Are you kidding? We will never give up on you.

Richard

[waterbear]

yep, it tests total hardness...and there are some known issues with the test that have been discussed on the forum before so it is not the most accurate. It is not what you need. You need a calcium hardness test such as the one in Ben's test kit or a taylor K-2006

As far as acid goes, use muriatic...comes in gallon jugs. Be aware that this is just another name for hydrochloric acid so have some repect for it.

[karenkr]

I will get some muriatic acid tomorrow. I am assuming I can get it at Ace?
Oh and should I use the cal hypo or should I stick to bleach.
I have wanted to get Bens test kit or the Taylor kit but I have never ordered anything on line(we dont use or have credit cards) and have been unable to find the Taylor kit locally. We live in a small town and do not have a pool supply store. so I have to depend on Wally world or ACE. Next time we go to the big city "Tulsa" hope to be able to locate a pool store.
Thanks for the info and help--will let you know how it goes with the acid
Karen

[chem geek]

We really don't know what your Calcium levels are yet so stick to bleach if you can, though if you already have some Cal-Hypo you want to use up that's probably OK if it's only enough chlorine for about a month.

[waterbear]

I will get some muriatic acid tomorrow. I am assuming I can get it at Ace?
They should carry it...the one I work in does but we have a HUGE pool dept.
Oh and should I use the cal hypo or should I stick to bleach.
I have wanted to get Bens test kit or the Taylor kit but I have never ordered anything on line(we dont use or have credit cards)
Just a suggestion. If your checking account has a visa ATM card you can use that with paypal and order from Ben.
and have been unable to find the Taylor kit locally. We live in a small town and do not have a pool supply store. so I have to depend on Wally world or ACE. Next time we go to the big city "Tulsa" hope to be able to locate a pool store.
Thanks for the info and help--will let you know how it goes with the acid
Karen
hope this helps.

[karenkr]

Thanks Waterbear
I did find some acid, purchased a gallon. Our ACE store has a small pool supply area. No kits except HTH like I have.
I have not used Pay Pal either. Was wondering if I could send a check, guess I could email Ben and find out. He could wait until it clears if he wants.
Just added 28oz of acid, have 6 boys coming today for a swim party so hopefully that will work. How long does it take before I would notice a change in my PH and TA?
Thanks to you Chemgeek for all your help also
You guys have been great!!!!
Karen

[chem geek]

Chemicals you add to your pool usually mix rather quickly. Usually within an hour, your entire pool will have some of the chemical you've added to it. I did a test using some colored dye and found that when the pump was running and when I poured it over the return jet in the deep end, it spread fairly evenly throughout the pool within a half hour (most of it within 15 minutes).

Now there are some websites that I've seen that say you have to wait longer before measuring pH because it takes a while to stabilize, but I've never seen any chemistry justification for that. All of the reactions that I'm aware of in the pool are very fast (except for chlorine breakpoint). Only the slow pH rise due to outgassing of carbon dioxide is very slow and that will never stabilize since you always keep your pool intentionally out of balance in order to maintain a TA level (with a pH near 7.5).

So my opinion is that you can test your pool chemistry an hour after you've added chemicals and you are likely to get a decent result -- so long as you have your pump running the entire time.

Richard

[karenkr]

Re-tested my pool. The PH and the TA did not change.
PH 7.8
TA 160
Should I add 28oz. more (per Bens chart)? I guess I am afraid I will add too much.
Suggestions???
Chlorine 8 would that have anything to do with my ph?
Thanks
Karen

[chem geek]

Re-tested my pool. The PH and the TA did not change.
PH 7.8
TA 160
Should I add 28oz. more (per Bens chart)? I guess I am afraid I will add too much.
Suggestions???
Chlorine 8 would that have anything to do with my ph?
Thanks
Karen
Karen,

Did you ever tell us the volume in gallons of your pool? 28 oz. of Muriatic Acid into a pool of 16,000 gallons would lower the pH to 7.44 and the TA to 153.5 so either you have a much larger pool or something strange is going on. With the numbers you show, if you have a larger pool than you won't be adding too much.

Are you trying to follow the procedure in this thread (http://www.poolforum.com/pf2/showthread.php?t=191) to lower your alkalinity (TA)? If you want to stop fighting the pH rise and frequent additions of acid, then you'll need to follow the procedure to get your TA down to 100 or maybe even 80. Ben's procedure for lowering TA in the referenced thread has you add a lot of acid to get your pH down and then has you aerate which has the pH rise and you add acid to keep the pH down, all the while your TA will drop.

Let us know your pool size in gallons so I can roughly calculate what should happen when you add acid.

There's also a possibility that your high chlorine level is fooling you with your pH test. Usually a level > 10 will cause you problems, but maybe 8 is enough to cause concern. You are kind of in a difficult situation with high chlorine and trying to measure pH (more on that in my next post).
Richard

[karenkr]

My pool size is 35000 gal. I was gong by Bens chart. Just wanted to lower the TA mainly and bring Ph down to 7.2.
Change of subject: did you see my other post on CYA tablets? Need some help there too!!!!

[chem geek]

With your 35,000 gallon pool and also adding in the 120 ppm CYA that I forgot about (since that also buffers pH), the 28 ounces of Muriatic Acid would have your pH drop to 7.66 and your TA drop to 157 so you might not have noticed this.

Also, as for testing pH with high chlorine, you can add one or two drops of Sodium Thiosulfate (chlorine neutralizer) which is the same reagent you use in your TA test and mix before you add the pH Indicator Solution. Unfortunately, the Sodium Thiosulfate will raise the pH and give you a falsely higher reading, but only by about 0.1 or 0.2 pH so at least you can get rid of the high chlorine to make sure that you aren't really falsely reading a high pH. My guess is that you are reading correctly since your high TA will pretty much force your pH up, but I'm just giving you another alternative to make sure. In general, you don't use Sodium Thiosulfate with the pH test.

I'll check your other post on CYA tablets and respond to that separately.

Richard

[waterbear]

[quote=chem geek

So my opinion is that you can test your pool chemistry an hour after you've added chemicals and you are likely to get a decent result -- so long as you have your pump running the entire time.

Richard[/quote]
I agree with this based on my limited knowledge of chemisty and from my own observations!