Who to believe - "byhand" or computerized water test?

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Henry_R
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Joined: Fri 20 Mar, 2009 21:41
My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

Who to believe - "byhand" or computerized water test?

Postby Henry_R » Wed 27 Jul, 2011 19:30

Ok, I didn't find another place to ask this so I put it here. I am helping maintain a community HOA pool.
(I had to do this a couple of years ago whilst we were not using the pool since it needed replastering. So I know a little about how to do it but I'm no expert.)

It is a Plaster/Gunite pool. 36'x18' 3.5' to 6' deep. Details should show up in my profile. We just bought a new Hayward sand filter w/ side multiport side mount valve over Memorial Day weekend. It has worked well so far as I can tell. The old filter was as much as 25 year old and the sand of indeterminant age.

Our pool man failed us two weeks ago (July 11th) by letting our pool turn green for the third time in 8 weeks through the tablet feeder going empty. He's been fired when he gave us too many excuses and failed to show up.
Until we find another service we can afford we have to do this ourselves. We had the water tested at a Leslie's pools store which determined the CYA was >100ppm and phosphates were >1000 while chlorine was <1 or 0. This explained the green. That was two weeks ago on Thursday the 14th. They sold us some PhosFree, NoMorProblems and algaecide along with some trichlor and 73% cal-hypo. We also bought a vacuum and hose.

We had a company to bid on the pool who wanted to charge way too much for our meger budget, but they told us we should drain 2 feet of water out to get the CYA down. We did this Saturday(16th) and filled it back up. Using the cal-hypo shock and trichlor tablets in the feeder set at #2 on a scale of 0-10. Vacuumed the dead algae off the bottom. It has remained clean of algae, but not fully clear. Chlorine was in the 2-4 range on Monday (18th) after we refilled it. We've had swimmers in there with no issues nor complaints reported. I put some shock (about 1lb or so) in early on this past Sunday (24th) morning since we had a large amount of bathers on Saturday night and were expecting a small pool party on Sunday evening.

The only thing that has been a concern is that the water is not fullly clear. The bottom drain is barely visible whereas before the issue with the green pool is was usually crystal clear. We are only using the skimmer the bottom drain has been plugged up since the 1980s due to a leak.

Now today (27th), I took a sample of water to a pool store I trust. The last time I went there they were doing the tests by hand. Now they're using a computerized tester (ClearCare(tm) Expert) which shows the TC=9.89(high), FAC=9.89(high), CC=0, TA=113,pH=7.6, CH=363, CYA=47,Copper=0,Iron=0,TDS=1000, Saturation Index=0.3
The man put drops of water on a machine which gave a reading on the computer. Not just entering it manually as I've seen most times.

My neighbor who is also part of the maintenance commitee doing work on the pool took took a sample of water to Leslie's Pools and they did a normal manual test. That test shows the chlorine to be low and CYA very high >100 as it was two weeks ago. They told her to shut off the chlorine feeder and shock it again. They also sold us some clarifier for the loudy water too.

The person at Leslie's is one of the experienced clerks we have trusted in the past, but we are always sold something by her rather expensive, IMO. ex. algaecide when the pool is green. This is why I went to the smaller store for the test.

So this leads to my subject of this post. I have a delema. Who do we believe? The computer or the person?
I'm being instructed by the Board here to follow the Leslie's advice, but I really am not sure if it's accurate
information and I don't want to make the pool have more problems than it has had. The chemistry is almost right and I don't want it to go green again.

I cannot find any information on the computer unit used for the test online. The printout says "ClearCare(tm) Expert pool water analysis system". I tried to find information on this testing system and keep coming up with contact lens care. ARG! :? :?: Is there any one here who knows about it?

The last question I have is how much does water temperature affect the test results? The computerized test results were given based on 90-101 degree water. I had the water outside for a while before going into the store. I ride the bus, but it shouldn't have been 90-101 degrees I don't think. Does this skew the test any?

Sorry to be long winded...

Hopefully someone can advise me.

Thank you,

Henry


Money talks!? All it ever says to me is "goodbye!".
chem geek
Pool Industry Leader
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Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Who to believe - "byhand" or computerized water test?

Postby chem geek » Thu 28 Jul, 2011 00:57

Get your own good test kit -- either the Taylor K-2006 or the TFTestkits TF-100 . Also, read the Pool School to learn more so you don't get "pool stored". You really need to know the accurate CYA level since a higher CYA will require a higher FC level to be effective and if very high then water dilution would be the thing to do.
Henry_R
Swimming Pool Pro
Swimming Pool Pro
Posts: 126
Joined: Fri 20 Mar, 2009 21:41
My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

Who to believe - "byhand" or computerized water test?

Postby Henry_R » Thu 28 Jul, 2011 09:07

chem geek wrote:Get your own good test kit -- either the Taylor K-2006 or the TFTestkits TF-100 . Also, read the Pool School to learn more so you don't get "pool stored". You really need to know the accurate CYA level since a higher CYA will require a higher FC level to be effective and if very high then water dilution would be the thing to do.
I agree with getting the test kit. And I have read the Pool School. I've been through this stuff in the past with this pool, but that was when I wasn't expecting anyone to swim (pool was being kept closed for remodel). Now, it's open and I have to make sure things are balanced and swimable for my neighbors until we find a competent pool service who won't charge us $500 a month because it's mid-summer and they think because we're an HOA we have unlimited money. :evil: Every company has bid that much or more and don't seem to be doing more than the companies we've had in the past.

Problem is my neighbor who is also helping with the pool did not and will not follow what I say and is in charge, not me. She will believe whomever she assumes to be an "expert". And ass-u-mes that the Leslie's pool clerk who seems to be experienced is THE person to ask for issues. Ignoring that everytime there's a problem she comes away with a bill and chemicals costing $$.

I will work on making an order for the TF100. I also have to convince those who will reimburse me for it that we must buy it rather than the cheapo $30 kit from somewhere like Leslie's which they are out of stock of now anyway. And that won't be until tonight. But that kit, even if I ordered it today or tonight will take until the end of next week to arrive. Who's test should I believe in the mean time? I put clarifier in there around 10 pm last night so I expect to have to vac out some stuff now.

[edit] I just checked it and there was brown stuff on the bottom from the clarifier, I gather. I vac'd the bottom and it looks better than before. Maybe that's all it needed to become clear, but I still don't know whether to believe the human or the computer chlorine test. It's going to be around 98 w/ 105 heat index again today.

I also got a lead on the maker of the testing computer thing the guy used. This is it: http://www.clearcarecoverage.com/ [Edit]
Money talks!? All it ever says to me is "goodbye!".
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Who to believe - "byhand" or computerized water test?

Postby chem geek » Fri 29 Jul, 2011 01:34

I honestly can't tell you whom to believe. It's not just poor test equipment, but poorly trained people (i.e. temporary summer help) that can be a problem as well. That's why it's really important to get a quality test kit and do the testing yourself. If you order the TF-100 , you will get it VERY fast -- their shipping is very fast. Amato Industries is much slower and will take about a week, probably similar to Leslie's (but cheaper).

I'm not sure where you are getting $100. The TF-100 is $68 and even with shipping isn't going to be $100. Nevertheless, you really get what you pay for with this kit as it has more volume of reagents that you use the most.
Henry_R
Swimming Pool Pro
Swimming Pool Pro
Posts: 126
Joined: Fri 20 Mar, 2009 21:41
My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

Who to believe - "byhand" or computerized water test?

Postby Henry_R » Fri 29 Jul, 2011 06:57

chem geek wrote:I honestly can't tell you whom to believe. It's not just poor test equipment, but poorly trained people (i.e. temporary summer help) that can be a problem as well. That's why it's really important to get a quality test kit and do the testing yourself. If you order the TF-100 , you will get it VERY fast -- their shipping is very fast. Amato Industries is much slower and will take about a week, probably similar to Leslie's (but cheaper).

I'm not sure where you are getting $100. The TF-100 is $68 and even with shipping isn't going to be $100. Nevertheless, you really get what you pay for with this kit as it has more volume of reagents that you use the most.
I see. The thing is in both cases the person who performed the test is a long time associate of the store. The man who performed my test is a manager of the store and he's no spring chicken. It's a small family owned store. The same can be said of the lady my neighbor delt with a Leslie's; we first shopped there in 2009 and she was there then too.

Anyway, I do want to get a TF100, but I still have to wait for it and I don't have the money until I'm authorized so I can be reimbursed. I did not hear from my HOA last night so I'm waiting.

I'm on fixed money and with the gvmt crap going on in Washington threatening my income :evil: I can't spring money I might not get back right away.

Is there any likelyhood of a local pool store or anywhere else in Houston carrying a TF100 kit? Or is it only sold from that place you linked to above? If it were local we could go in with an HOA check-in-hand and purchase it rather than waiting for shipment. The HOA doesn't have a CC which would of course make thing easier.

BTW, is it worth getting the XL option with that TF100 if order it?
Money talks!? All it ever says to me is "goodbye!".
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Who to believe - "byhand" or computerized water test?

Postby chem geek » Fri 29 Jul, 2011 10:55

The TF-100 is only available online. The Taylor K-2006 might be available at some store, but unlikely since they normally carry the K-2005 which is not the same thing (it uses the DPD chlorine test instead of the FAS-DPD chlorine test you really need). As for the XL, you probably don't need that amount of reagents unless you are cleaning up a swamp and have high FC levels you are testing frequently. The reagents don't last forever -- the DPD powder and FAS-DPD titrating drops shouldn't go for more than about 2 years (Taylor recommends replacement every year, but you can usually go longer if you keep them in a cool dry place).
Henry_R
Swimming Pool Pro
Swimming Pool Pro
Posts: 126
Joined: Fri 20 Mar, 2009 21:41
My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

Who to believe - "byhand" or computerized water test?

Postby Henry_R » Fri 29 Jul, 2011 21:29

chem geek wrote:The TF-100 is only available online. The Taylor K-2006 might be available at some store, but unlikely since they normally carry the K-2005 which is not the same thing (it uses the DPD chlorine test instead of the FAS-DPD chlorine test you really need). As for the XL, you probably don't need that amount of reagents unless you are cleaning up a swamp and have high FC levels you are testing frequently. The reagents don't last forever -- the DPD powder and FAS-DPD titrating drops shouldn't go for more than about 2 years (Taylor recommends replacement every year, but you can usually go longer if you keep them in a cool dry place).
RATS! Ok, I'll have to order it. Wow the shipping is a lot for USPS priority mail which I prefer. FedEx Home is cheapest, but I've had nothing but troubles with them not finding my condo and delaying shipment for days. I've even waited all day home here to have them not show up at all. :problem:

I have to email TFTKits and see if they can send it by FedEx Ground instead. They have a delivery instruction field on the order form, but I'm not sure if they'll follow what I say.
I cannot call them 'fore I have no long distance service on my phone. Oh well so much for getting the kit fast.

How long should it take for chlorine to decay if it really was at 9.89? I'm going to have to ass-u-me that the chlorine was high since we've had bathers in there and it's not becoming a swamp. There are none of the telltale signs of algae that I usually associate with algae forming.

It's been almost two days and I've had the tablet feeder shut off since Wednesday evening and have not added any more chlorine. The water is free of algae, but as before it's not fully clear either.
In the pool light which is LED based I can see what looks like silt suspended in the water.
Money talks!? All it ever says to me is "goodbye!".
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Who to believe - "byhand" or computerized water test?

Postby chem geek » Sat 30 Jul, 2011 02:18

How fast the FC drops depends on whether the pool is in full sun and on the CYA level. At CYA levels of around 50 ppm, 40-50% of the FC can be lost in a long summer day. At 80 ppm CYA, the loss is around 20-25%. At 30 ppm CYA, the loss is around 70%. If you have high bather load then that loss can be higher than that from sunlight.
Henry_R
Swimming Pool Pro
Swimming Pool Pro
Posts: 126
Joined: Fri 20 Mar, 2009 21:41
My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

Who to believe - "byhand" or computerized water test?

Postby Henry_R » Sun 31 Jul, 2011 02:18

chem geek wrote:How fast the FC drops depends on whether the pool is in full sun and on the CYA level.
At CYA levels of around 50 ppm, 40-50% of the FC can be lost in a long summer day. At 80 ppm CYA, the loss is around 20-25%. At 30 ppm CYA, the loss is around 70%. If you have high bather load then that loss can be higher than that from sunlight.
OK. This confirms that the CYA is at least 100 as now two different tests have indicated. I had the water tested again. I have to rely on the pool store people until my kit is ordered and received. :eh:

The test indicated the TC/FC was at least 4 and CC=0 with CYA around 100. pH about 7.5 or 7.6 so it hasn't changed by much. CH has bounced up to 500 for some reason with no addition of chlorine power since last weekend. :? I looked at these results myself and the colors seemed to be right, FWIW. I guess I need to replace some water to get the CYA and CH down, not fun...

I need to add some cal-hypo in the morning based on these numbers. 2lbs I think.
Will if be OK to swim in the afternoon if I shock it in the morning with the water holding
chlorine so well as it is though? It's taken 4 days to drop chlorine from >9.8 to 4.
Perhaps I need to warn people to rinse well after bathing?

Lastly, how does one gauge how much chlorine is added for each notch on the chlorine tablet feeder? When we drained and refilled the pool three weeks ago I set the feeder to #2 to provide chlorine and this was obviously too much since the CYA bounced back up. Is there a formula or something for each setting of how much chlorine it provides?

I know each trichlor tab provides an amount of chlorine and CYA so there has to be a formula for each setting on the feeder. The feeder is a rainbow lifeguard type. It's old probably from the 80s or 90s.
Money talks!? All it ever says to me is "goodbye!".
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Who to believe - "byhand" or computerized water test?

Postby chem geek » Sun 31 Jul, 2011 23:08

The following are chemical facts that are independent of concentration of product or of pool size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

You are right that with your high CYA especially, and to a lesser extent with your somewhat high (though still manageable) CH, you need to dilute your water to lower these levels. As you can see from the above, even at a daily 1.5 ppm FC per day loss which is what you are seeing, that's an increase in CYA of over 25 ppm PER MONTH from Trichlor.

You need to check your county/state regulations since your HOA may fall under commercial/public pools and have very specific requirements for various chemical levels. If there is a maximum FC limit that is lower than I suggest, then you'll have to follow that limit and use alternative means to prevent algae growth, such as using Polyquat 60 weekly (at extra cost).

With your 100+ ppm CYA, if you maintain the FC level at around 10 ppm using chlorinating liquid or bleach so as not to raise the CYA nor CH levels, then you will prevent algae growth unless the CYA level is more like 200 ppm. With your high CYA level, a high FC level will not be harsh on swimsuits, skin or hair. 10 ppm FC with 100 ppm CYA is roughly equivalent in active chlorine level to a pool with only 0.1 ppm FC and no CYA. The only issue with the higher FC level is if people were to drink very large quantities of pool water on a regular basis (which obviously they shouldn't be doing anyway).

You should get your CYA level closer to 50 ppm. You should also consider using chlorinating liquid and getting an automatic dosing system such as a peristaltic pump or The Liquidator . If you want to continue to use Trichlor tabs, then you'll need to use a supplemental algaecide such as Polyquat 60 weekly or a phosphate remover or use 50 ppm Borates. Even so, the regs will probably require you to dilute the water to keep the CYA under 100 ppm.

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