ozonator

Problems relating to pH and total alkalinity.
Increase ph, increase TA. Reduce pH, reduce TA.
pH chemistry advice and techniques for the pool.
edpool

ozonator

Postby edpool » Tue 15 Apr, 2008 17:26

Would an ozonator be a great aerator?


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Postby chem geek » Tue 15 Apr, 2008 17:43

Why do you ask? Yes, an ozonator will aerate the water so generally the pH will rise when you have an ozonator (especially in a spa) unless you use an acidic source of chlorine (Trichlor or Dichlor -- yes, Dichlor is actually acidic when accounting for chlorine usage; both of these will add to Cyanuric Acid level).
edpool

Postby edpool » Wed 16 Apr, 2008 17:59

Would you not recommend muriatic acid as a source to lower ph in a spa/pool with ozonator and salt generator? Thanks.
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Postby chem geek » Wed 16 Apr, 2008 20:06

For a pool, Muriatic Acid (31.45% Hydrochloric Acid or its half-strength 15% version) is generally used to lower pH. For a spa, dry acid (sodium bifsulfate) is normally used as the dry version is easier to handle in small quantities. You have to be careful with either, wear protective eyewear, and add the acid very slowly over a return flow with the pump (but not aeration jets) running.

You can reduce the rate of pH rise from the aeration by having the TA be lower, but don't go below 50 in any event. In an SWG pool, one usually doesn't go below 70.

Richard
edpool

Postby edpool » Wed 16 Apr, 2008 20:38

Thanks again. Any good source for acid? I'm spending a lot for acid alone.
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Postby chem geek » Thu 17 Apr, 2008 00:35

You can get Muriatic Acid at pool stores, many hardware stores (OSH, Home Depot), large super-stores like Wal-Mart, Costco, etc. Dry Acid is sold at a subset of these that sell pool/spa chemicals (Muriatic Acid isn't just used for pools, but also as a general acid for acid washing and other uses).
edpool

Postby edpool » Thu 17 Apr, 2008 14:38

One more thing, I was asked to ignore TDS due t salt water system. Is this true?
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Postby chem geek » Thu 17 Apr, 2008 15:25

You still account for TDS when determining the saturation index so that your pool has proper water balance, but yes the TDS will be high in a salt pool and that's fine. TDS by itself is never a problem -- it's what the TDS is composed of that could be an issue. In pools that use stabilized chlorine, a high TDS can mean older water and that can mean high CYA levels, but it's the CYA that is the problem and not the TDS itself. Mostly, TDS is just salt (either sodium chloride and calcium and bicarbonate).

So only consider TDS for the saturation index and don't worry about it for anything else in a saltwater chlorine generator (SWG) pool.

Richard
edpool

Postby edpool » Fri 18 Apr, 2008 06:37

Just to clarify, when you say saturation index, how do I exactly measure it? Thanks.
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Postby chem geek » Fri 18 Apr, 2008 10:34

You can use The Pool Calculator.
shonda

help

Postby shonda » Mon 21 Apr, 2008 11:40

my cl was high but now is .5 light yellow....

my ph is down to 7.2

my water is clear to cloudy can see second step well

my ta is bounced in the past week from 80 to 300 to right now 230

what do I do first....

add acid? liquid ma poured into deep end?
what about the ph going down below soda ash 7.2 do I add bicarb after I add the acid? God help me....then what?

thanks....to all the pool angels!
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Postby chem geek » Mon 21 Apr, 2008 12:38

There is no way the TA bounced from 80 to 300 to 230 unless Alkalinity Up (sodium bicarbonate; baking soda) was added to the water. This sounds like a measurement problem. Get yourself a good test kit, the Taylor K-2006 which you can get at a good price online here or the TF100 test kit from tftestkit(dot)com here. The latter has 36% more volume of reagents so is comparably priced to the first link per test.

First thing to do is to add more chlorine to the water (chlorinating liquid or unscented bleach) as your water is probably turning cloudy due to algae growth. Do not add any acid since your pH is already low. I doubt that your TA is really as high as you say since the pH would likely be rising in that case.

What kind of chlorine are you using? Are you using Trichlor pucks/tabs in a floating feeder or inline chlorinator? The low pH would usually indicate using that sort of chlorine which will not only add chlorine, but also Cyanuric Acid (CYA) to the water. Again, get a good test kit and a full set of numbers since we can't know how much chlorine you will need or what to do next until we know your pool's CYA level. If it's extraordinarily high, then a partial drain/refill will be needed. Otherwise, a higher chlorine level will suffice.

Richard

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