very confused

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confused
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very confused

Postby confused » Sat 10 May, 2008 07:57

Well, where do I start. We have installed a used 33' pool. I have done a lot of research online and talked to several pool comp. They have all told me something different. Here are some of the things I am confused about:

1) chlorine-- I know trichlor and dichlor are chlorine with stabilizers. One guy told me I can use both and it probably won't effect my cya (they are both so low in cya) and one lady told me not to use both or my cya would go so high that I would have to possibly drain my pool.

2) I can't find out where to buy regular chlorine besides pool stores. I would use bleach but wow how much would I need for a 33' pool and how often. I read where liquid chlorine evaporates so quickly.

3) I was going to use trichlor 3" tabs but I know I will need to add more chlorine. Can someone help me? I thought about using calcium hypochlorite but the hardness in the pool is 360 already and I read it would make it worse. Maybe I need liquid chlorine or maybe just the bleach.

4) I have also read where you need to shock your pool a lot but most of the pool stores say no no.

5) the alkalinity in the pool is 390 and ph is 8. I think I need to do muriatic acid a little at a time and test again then add more and test again. Am I right?

This ia all looking overwhelming. I am not sure who to ask about anything because I keep getting different answers. I called one pool store today and was tryijng to ask questions along with what I thought was right and he kind of hung up on me.. I guess I stumped him.

I have been trying to read up on pool maint. and chemicals for quite some time now and I feel like I am still at square one. Can anyone please help? :?


another nowbie post

grab a coffe, sit back and read ...

Postby another nowbie post » Sat 10 May, 2008 09:00

Read these forums, soon after they get their coffee they will come and tell ya what to do.

I also started with a new pool this year, knew NOTHINg about them and these guys (Namely chem guy) walked me thru it, and saved me hundreds of dollars.

Once I came here, I spent 26 bucks to clear my pool, now I can see the screw heads on the deep end (9ft) drain cover. Youll be fine. Just AVOID the pool store at all costs, all they wanted was my money. Definatly look at the BBB posts, so much wealth of knowledge there.
chem geek
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Re: very confused

Postby chem geek » Sat 10 May, 2008 13:23

One place to start with education is with these Stickies at TroubleFreePool. The "ABC's of Pool Water Chemistry" would be the first thing to read. The rest of your questions I try and answer below.

1) chlorine-- I know trichlor and dichlor are chlorine with stabilizers. One guy told me I can use both and it probably won't effect my cya (they are both so low in cya) and one lady told me not to use both or my cya would go so high that I would have to possibly drain my pool.

The guy was just plain wrong. The chemical fact is that with Trichlor, for every 10 ppm Free Chlorine (FC) that it adds, it also increases Cyanuric Acid (CYA) by 6 ppm. With Dichlor, for every 10 ppm FC that it adds, it also increases CYA by 9 ppm. So between the two, for the same amount of chlorine, the Dichlor will increase CYA faster than Trichlor. Generally speaking, one should not use Dichlor unless one intentionally wants to increase the CYA level over time via chlorine addition.

Though chlorine usage varies, even 2 ppm FC per day would be a buildup using Trichlor of 36 ppm CYA per month or over 200 ppm CYA over 6 months. This will only get reduced through dilution (not evaporation) so only by splash-out, backwashing, or intentional partial drain/refill. So only small sized pools that have sand filters backwashed frequently tend to keep their CYA somewhat reasonable; larger pools with cartridge filters have the CYA climb quite rapidly.

Even in my own pool that has an opaque safety cover still had the CYA build up to 150 ppm in just a year and a half (at around 0.8 ppm FC per day with a 7-month swim season) at which point I started to have problems with higher chlorine usage which was nascent algae growth -- and I was using a PolyQuat 60 algaecide, but only doing so every other week. That's when I educated myself on the chemistry of pool water and found the chlorine/CYA relationship in a 1974 scientific paper -- yes, this stuff has actually been known for nearly 35 years yet the industry for whatever reason chooses not to educate the public or pool stores about this. I now only use chlorinating liquid except during the start of the season if the CYA is low (I tried using Dichlor this year to raise the CYA -- I think I'll use pure CYA next year even though it's slower to dissolve).

Trichlor is very acidic, especially when accounting for the usage (breakdown) of chlorine which is an acidic process. This means that you would need to add pH Up product (sodium carbonate; same as Arm & Hammer Washing Soda) or 20 Mule Team Borax to keep the pH up. So though Trichlor would at first appear to be the cheapest source of chlorine, it really isn't when accounting for other chemical costs and this is described here.

You can use Trichlor in a floating feeder or inline chlorinator, but if you want to prevent algae as the CYA level builds up then you would need to use a supplemental algaecide such as PolyQuat 60 or a phosphate remover. The maintenance quantity of these supplemental products is around $2-3 per week depending on pool size. Another alternative to keep the CYA in check is to do frequent or significant dilution of the water.

Of course, the least expensive source of chlorine is chlorinating liquid or unscented bleach (the only difference between these being their strength). However, it does take more work since you have to manually dose the pool every day or two unless you have a pool cover in which case twice a week is possible. To automate the dosing of chlorinating liquid or bleach, you can use The Liquidator talked about in this thread. Because the CYA does not build up, there is no need to use supplemental algaecide if the FC is maintained relative to the CYA level. To prevent algae growth, you need to have an absolute minimum FC level that is at least 7.5% of the CYA level if you want to prevent algae growth (this rule works up to a phosphate level of around 3000 ppb or so which is very high). The normal target FC is 10% of the CYA level since this is easy to remember and gives a little safety cushion.

2) I can't find out where to buy regular chlorine besides pool stores. I would use bleach but wow how much would I need for a 33' pool and how often. I read where liquid chlorine evaporates so quickly.

I need more information than just the length of the pool which I assume is the 33' dimension. What is the pool size in gallons or if you don't know that then what is the shape and either width, height and depth at shallow and deep ends or if a round pool what is its diameter and depth?

Liquid chlorine does not evaporate quickly. ALL sources of chlorine produce identical chlorine in the bulk pool water and this includes their rate of loss which is mostly due to breakdown from the UV rays of sunlight, not from evaporation. Evaporation (actually outgassing) of chlorine is mostly an issue at higher water temperatures such as in spas or hot tubs.

A typical pool size is 15,000 gallons which would be 15'x30'x4.5' (depth from 3 to 6 feet) and would require about 4 cups (1 quart) of 6% bleach (e.g. Clorox Regular or off-brand Ultra) to raise the Free Chlorine (FC) by 1 ppm. Daily chlorine usage varies a lot, but 2 ppm is not uncommon so figure 2 quarts per day or 3.5 gallons (4-2/3 96-ounce jugs) per week. It is more convenient to buy 12.5% (or even 10%) chlorinating liquid if you can find it as it's about half as much to carry and use and it isn't always that much more expensive per FC. I get 12.5% chlorinating liquid from my local pool store at around $3.65 per gallon which is equivalent to $1.35 per 96-ounce of 6% bleach and they reuse the bottles which is better than recycling them (there is a small refundable deposit for the bottles and milk-carton case). You might look at Home Depot, Orchard Supply Hardware, and other such big box stores for chlorinating liquid while Costco and Wal-Mart are usually inexpensive sources for bleach. I have an electric opaque safety cover on my pool so my chlorine usage is only 0.5 - 1 ppm FC per day depending on use (1 ppm is use every day).

You can use The Pool Calculator to figure out dosing of chemicals for your pool.

3) I was going to use trichlor 3" tabs but I know I will need to add more chlorine. Can someone help me? I thought about using calcium hypochlorite but the hardness in the pool is 360 already and I read it would make it worse. Maybe I need liquid chlorine or maybe just the bleach.

With Cal-Hypo, for every 10 ppm FC that it adds, it also increases Calcium Hardness (CH) by 7 ppm so you are right that you shouldn't use it since your CH is already a little high.

Nevertheless, you do want SOME CYA in your pool or else the chlorine will break down from sunlight too quickly (and without CYA, a pool will be over-chlorinated and oxidize swimsuits, skin and hair too quickly as is the case with most indoor pools since they generally don't use CYA though they really should use some -- another side effect of incomplete information from the industry that ignores the chlorine/CYA relationship). For a manually dosed pool, a CYA level of 30-50 ppm is common though some people run higher, but you must be more diligent if you use a higher CYA since it takes more chlorine to shock the pool to get rid of algae if you forget to add chlorine.

4) I have also read where you need to shock your pool a lot but most of the pool stores say no no.

A properly managed chlorine pool will hardly ever need shocking (super-chlorination). I can usually go an entire season without shocking or sometimes doing so just once. This partly depends on the bather load of your pool such as after a pool party or if a lot of junk (leaves, etc.) gets in the pool or, especially, if a dead animal or bird poop gets in when you usually want to shock to be on the safe side (though technically it's not necessary and you can just wait and maintain the FC level -- chlorine kills pathogens very quickly). An outdoor pool exposed to sunlight and always maintaining an appropriate FC level relative to CYA is continually breaking down urea/ammonia that are the primary sources of Combined Chlorine (CC), namely monochloramine. I hardly ever measure any CC above 0.2 ppm and never over 0.5 ppm.

5) the alkalinity in the pool is 390 and ph is 8. I think I need to do muriatic acid a little at a time and test again then add more and test again. Am I right?

Your TA is way too high. Is this from the fill water? Test your fill water and be sure to get yourself a good test kit -- either the Taylor K-2006 kit you can get at a good online price here or the TF100 test kit from tftestkits(dot)com here with the latter having 36% more volume of reagents so comparably priced "per test".

With a high TA, your pH will tend to rise frequently. You can lower your TA level by following the procedure described in this post. It will take a LOT of Muriatic Acid and aeration to lower the TA. For a 15,000 gallon pool, going from a TA of 390 to 80 (and a pH of 8.0 to 7.5) will take a cumulative total of 9.3 gallons of Muriatic Acid (31.45% Hydrochloric Acid) though obviously not added all it once. Just the first step to lower the pH from 8.0 to 7.0 would take almost 2 gallons.

By the way, your current numbers of pH 8.0, TA 390, and CH of 360 give a saturation index of over +1.1 which is way too high. Your water is likely to produce scaling so you should get your pH lowered right away and might as well start the TA lowering procedure immediately. Be sure to get yourself the good test kit first since bad test results will just throw you off.

This ia all looking overwhelming. I am not sure who to ask about anything because I keep getting different answers. I called one pool store today and was tryijng to ask questions along with what I thought was right and he kind of hung up on me.. I guess I stumped him.

I am sorry people are not being helpful. You can find a lot of help at TroubleFreePool where lots of knowledgeable people will hold your hand through every step of the process. Before you know it, things will become much easier.
confused
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TA

Postby confused » Sun 11 May, 2008 07:48

I added 1 gal of muriatic acid and the TA went down from 390 to 360. Ph is 7.5. I guess I will add 2 more gal. of acid and then try to raise my PH with borax and then keep doing this til the TA comes down. Is this right?
I am not sure why the TA was so high with fill water.

Thank you so much for the information. I think I will take back the dichlor I bought and just buy bleach. I found 12% bleach at a janitorial store for 19.? for 5 gal. We are putting muriatic acid in right now but some guy told me it would only take 2-3 gal. and to do 1 gal at a time. I think I will go ahead and dump in another one. Our pool is 25,000 gal. and yes it was fill water. I think it will take a lot of bleach to get it going at first. Do you think I should add just a little reg. cya increase along with the bleach and then start using a little trichlor tablets or maybe according to your post just add cya increase and use bleach alone?
I wonder why our TA is so high with fill water. Is this normal? We do have terrible rusty water and all. Our test kit is from Arch Chemicals. It tests 5 diff. things. CYA, PH, TA, TH TC. Have you ever checked out aquagems website? They sell a product called extreme clean. Just wondering if you had ever heard of it? I decided to try it this year for algae, phos. remover etc.

Thanks again for being so nice and willing to help.

If you already got this message I am sorry. I am new to this and am really not sure where to post or reply.
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Postby muss08 » Sun 11 May, 2008 08:54

A couple answers until chem geek get s back to you. It is definitely going to take way more than 2-3 gallons of acid to get your TA in line. The guy may have meant your pH. You want to watch your pH as you are adding the acid. You dont want to let your pH get below 7.2. Lower than this will cause the water to become corrosive. With your TA so high your pH is going to want to naturally creep back up, however, as chem pointed out, aeration will raise your pH up faster allowing you to add more acid quicker. I have never seen TA that high in fill water.
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Postby chem geek » Sun 11 May, 2008 09:38

Is the fill water from a well? Well water can sometimes be high in TA, CH or both. Usually river, stream, reservoir water is not.

To lower the TA, the procedure is to first lower the pH to the next to lowest measurement setting on your pH test, but not lower than 7.0 in any event. So if you pH test goes down to 6.8, then 7.0 is the lowest to go. If the pH test goes down to 7.0, then 7.2 is the lowest to go. muss08 is generally right that you don't want pH to get too low, but you're not going to have the pH low for that long -- perhaps a week at the most -- and corrosion doesn't happen that fast unless the pH is quite a bit lower. At any rate, you can have 7.2 as your bottom target with no problem.

So you first add acid to get down to, say, 7.2 in pH. Then aerate the heck out of the water -- point returns up, use a fountain (submersible pump connected to fountain) or if you have aerating water features like a waterfall, turn them on. If you have an air compressor, you can submerge the hose end into the deep end and if you have a nozzle with many small holes then that will create a lot of aeration. There is also this fountain or this aerator you can use.

The aeration will make the pH rise faster at which point you add more acid to keep the pH down at, say, 7.2. The combination of aeration plus acid addition will lower the TA. When you get to the TA level you want, then you stop adding acid and just aerate to get the pH back up to around 7.5 and you're done.

Richard
confused
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TA

Postby confused » Sun 11 May, 2008 12:30

Thank you so much for all the help. Wow, I finally feel like I am getting somewhere. The water we used was well water. The city would not fill it and it would cost like $2,500 or so to have "the pool lady" fill it. I am going to go ahead and put in the trichlor tabs so the CYA can start going up since there is none.

Thanks again for all the useful tips and who knows, I will probably be back posting soon. Everybody told me there was not much to taking care of a pool but I am starting to wonder what they were thinking. Maybe after this first inital fill things will get better.
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Keep it simple...

Postby njshorepools » Sun 11 May, 2008 13:04

I use tri chlor in all of our pools with no problems with cya. If your cya is low and your using tri chlor u MAY still need to add stabilizer... play it by ear..or eye for this matter... not sure if anyone mentioned this but well water USUALLy has high metals in it. Have it tested for metals or u could get some nasty staining. If you test your water once a week and give your pool a half hour per week of your time it will love u and mainting it will be easy.. its when u let it go for weeks with no love when things go wrong... its like our women... gotta show it some love 8)
a SAFE pool is a HAPPY pool...
chem geek
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Re: TA

Postby chem geek » Sun 11 May, 2008 14:39

confused wrote:Thanks again for all the useful tips and who knows, I will probably be back posting soon. Everybody told me there was not much to taking care of a pool but I am starting to wonder what they were thinking. Maybe after this first inital fill things will get better.

Once you are set up it IS easy. I only add chlorine twice a week to the pool and that's it -- all season long. I have an opaque electric safety cover so don't get much evaporation nor outgassing nor sun in the water so chlorine usage is low. Every pool is different, but it's not much work, especially if chlorine dosing is automated (The Liquidator for chlorinating liquid or bleach or an SWG for on-site generation). Your situation is harder than most because you are starting out with a high TA level; that just means having to add more acid -- either in a short period of time using aeration to lower TA or over a longer period of time to try and keep the pH lower.

As for the other post about Trichlor with no problems, that is true if the Free Chlorine (FC) is kept high enough relative to CYA level or if a supplemental algaecide is used or a phosphate remover used, but these extra items cost more. If you look at pool posts, it doesn't take neglect to run into problems. My own pool years ago had just Trichlor and never got too low chlorine (in an absolute sense), but when the CYA hit 150 ppm after just one and a half years of use then the chlorine demand outstripped the ability of the Trichlor to dissolve quickly enough -- I had nascent algae growth just before getting to the visible stage. You can certainly use Trichlor in pools, but if the CYA continues to build up and you don't mitigate with higher FC or algaecide or phosphate remover, you are much more likely to run into problems. Remember that the 1-3 ppm FC "standard" recommendation doesn't work well when people only have 1 ppm FC with 100 ppm CYA or more. 3 ppm FC is dicey though OK if phosphate levels are lower. With Trichlor, for every 10 ppm FC that it adds, it also increases CYA by 6 ppm. Just 2 ppm FC per day would add 36 ppm to CYA every month or over 200 ppm CYA in 6 months. It builds up quickly unless you have a small pool with a sand filter and regular backwashing or otherwise have lots of dilution from splash-out and partial drain/refill.

So to "confused" you can certainly use Trichlor if you want to as it is acidic and will help keep the pH from climbing as fast from the high TA, but as the CYA builds up you'll need to supplement with an algaecide or phosphate remover at higher cost (around $2-3 per week for either algaecide or phosphate remover maintenance amounts; with phosphate tests, you could use less remover over time depending on your situation).

Richard
John75

very confused

Postby John75 » Sat 10 Mar, 2012 19:43

Hi Paul! Have you checked this guide to swimming pool water chemicals at www.indoorpoolguide.com/water-chemicals

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