How warm does a water sample need to be to get accurate test results? Will I get accurate test results if I let my water sample warm up inside for 3-4 hours or warm it up quickly by setting the water sample in a container of hot water? I recently tested my pool water which is 65 degrees and it said that my CYA and calcium are much higher than they were 2 weeks ago. I know these results aren’t accurate since I haven’t added any stabilizer, Dichlor, trichlor, cal hypo, or calcium to my pool. I need to get accurate test results before closing my pool so I will know what to add before closing. Two weeks ago, my CYA appeared to be 30 so I was planning on adding some liquid CYA to get it to 40 before closing so I don’t open up to zero CYA like I did last year due to our mesh cover. I also usually have to add some muriatic acid at closing but I don’t trust my PH test results since the CYA and calcium results appear to be so inaccurate.
Testing a cold water sample
- Thread starter Nadadora
- Start date
- Mar 5, 2020
- 3,173
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
The only test that needs the water to be not too cold is the CYA test.
For FC the sample should be as fresh as possible so that FC doesn't decay in the meantime.
pH you want to test at the actual pool water temperature. pH will naturally drop as the water temperature rises. You want to know the pH as it is in your pool, not once the water sample has warmed up.
For TA and CH it doesn't really matter.
For FC the sample should be as fresh as possible so that FC doesn't decay in the meantime.
pH you want to test at the actual pool water temperature. pH will naturally drop as the water temperature rises. You want to know the pH as it is in your pool, not once the water sample has warmed up.
For TA and CH it doesn't really matter.
- Mar 5, 2020
- 3,173
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
- Mar 5, 2020
- 3,173
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
For the CYA test, how warm does the sample need to be to get accurate results? Can I warm up the sample quickly by placing the sample container in hot water or do I need to wait a few hours for the sample to warm up? I need to get an accurate reading on the CYA because I think it might be 30 or below since it was 30 a few weeks ago and we got some rain. When I tested the CYA yesterday, it was showing that the CYA was 50 which can’t be right since I haven’t added anything with stabilizer in it. I don’t have much CYA reagent left so I want to make sure my sample is sufficiently warm to get an accurate reading.
If the CH test isn’t affected by water temperature, do you know why I’m getting highly inflated results? My testing supplies are a year old and have been stored inside. If my testing supplies are too old now, I need to buy more before I open up my pool next Spring so I get accurate results.
- Jun 1, 2018
- 13,991
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
- Jun 1, 2018
- 13,991
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
CH was 300 but it was only 150 a few weeks ago so I know it isn’t accurate. TA was 100. PH appears to be 7.8, FC was 5, CC was .5 (probably due to leaves that I can’t keep out of the pool). If I warm up the sample and CYA is 30 or below, can I get liquid CYA to dissolve in colder water? (I don’t have time to use granular since I’m closing in a few days.) I would like to increase the CYA if it is 30 or below since my 15 year old mesh cover lets in water and doesn’t block out all of the light. Last year, I closed with a CYA of 40 and opened up to CYA of zero and green water so I worry about closing with a CYA of 30 or below. If liquid CYA won’t likely dissolve well in 65 degree water or it seems like a waste of money to use it, I will skip it and just close. I plan on adding polyquat as insurance since the water temperature isn’t below 60 yet and I have a mesh cover.
Granular CYA should dissolve in a sock in less than an hour. It’s cheaper and way more reliable. Hi it could also just leave a floater with some trichlor pucks in it over the winter. That’s worked well for me in the past.
- Jul 21, 2013
- 53,931
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Maybe the 150 reading was the incorrect one?
That is just a waste of money. The 10ppm of CYA you add will not accomplish anything.
Having a bit more CYA will not prevent a green pool opening.
Open your pool earlier before it turns green and get chlorine into it.
Yes, you should be adding PQ60.
Algaecide - Further Reading
www.troublefreepool.com
And closing with warmer water and a mesh cover is contributing to your green opening.
- Dec 13, 2020
- 780
- Pool Size
- 19600
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
With no first-hand knowledge of closing - we let our pool open in NC - the trichlor in a floater idea seems great. When our water drops to ~51F - usually early December - and the SWG is about to stop working, I switch to a floater with the vents completely closed. A couple of pucks last nearly a month and FC stays perfect. Of course that's with the pump going. But two summers ago our pump breaker tripped while we were in Italy on vacation. Had a floater in then, too. This was June. With 6 days of no pump, FC was still in the target range when we got home. Yikes that was great.
Our pool is surrounded by shade trees. Surely that helps a lot, but still...
Our pool is surrounded by shade trees. Surely that helps a lot, but still...
- Mar 5, 2020
- 3,173
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Cold water should make the CYA reading look too low rather than too high.
Are you testing with Taylor reagents?
Are you testing with Taylor reagents?
an1vrsy
Bronze Supporter
- Jul 10, 2018
- 1,153
- Pool Size
- 26000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
What works really well for testing CYA from a pool with cold water is:
- Add pool water to the first line in the CYA sample bottle and cap it.
- Then put the capped CYA sample bottle into your pocket. You'll feel that it is cold. By the time you have completed all of the other tests the CYA sample bottle would have warmed up to room temperature.
- Take it out of your pocket.
- Then add CYA reagent to the upper line, shake for 30 seconds.
- Then get ready to do the test, outside with sunlight, CYA bottle at your waist, sun at your back. Pour the sample into the tube, glance for the dot don't stare.
While 86 degree water is 'cold' in NV, its not cold as far as the testing is concerned. You don't need to stick it in your pocket.
I’m not able to close late or open up my pool too early because I’ve got overhanging and close trees that drop leaves into the pool in the fall and seeds in the spring. Would increasing the CYA from 30 to 40-50 help the SLAM go faster in the Spring? I closed with 40 CYA last year and opened up to 0 CYA this spring and the SLAM took longer than usual. I’d be willing to postpone the closing for a day or two to get some liquid or granular CYA into the pool if it could potentially help make the SLAM go faster. I’m also curious to know if putting a floater of chlorine pucks into the pool in the late winter or early spring might help like someone suggested on here. I’ve always been scared to use one under the cover if the pump is off because I’m afraid it will park itself along a wall or in the skimmer and cause staining in my pool. My fiberglass pool is white and I already have some stains that won’t come out that may have been caused from a pool guy who dumped powdered shock in my pool at opening and didn’t brush afterwards.Maybe the 150 reading was the incorrect one?
That is just a waste of money. The 10ppm of CYA you add will not accomplish anything.
Having a bit more CYA will not prevent a green pool opening.
Open your pool earlier before it turns green and get chlorine into it.
Yes, you should be adding PQ60.
Algaecide - Further Reading
And closing with warmer water and a mesh cover is contributing to your green opening.
an1vrsy
Bronze Supporter
- Jul 10, 2018
- 1,153
- Pool Size
- 26000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
But what do I do when it's snowing in Las Vegas, and the water is 50*?While 86 degree water is 'cold' in NV, its not cold as far as the testing is concerned. You don't need to stick it in your pocket.
If the water is green when you open it, something is wrong. Find a way to get some chlorine in it earlier than that even if you have to pull up the cover to add some directly.
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- Jul 21, 2013
- 53,931
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
No, raising your CYA is not the solution to your green pool problems.
- Jun 24, 2021
- 7,809
- Pool Size
- 30000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60
This is why you get algae in the spring. Closing with higher temps and opening with higher temps is your issue. It is allowing algae growth.
What type of cover do you have on the pool? If you can peel back a corner and test FC and use liquid chorine to chlorinate while covered would help. Drop a sump pump without any hose on it in an opened corner, turn it on, slowly pour in liquid chlorine and sump will distribute. Better yet, also throw in the dolphin if you have one. Maintaining FC once a week while it is "closed," likely will help you avoid algae.
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I put the sample bottle in my pocket like you suggested and also held it in my hand for 10 minutes and I finally got an accurate CYA reading. That was a lot easier than trying to warm up the entire water sample so I appreciate the tip. I’m still not getting an accurate calcium reading after warming up the collection tube so I wonder if my calcium reagents are expired even though they are only a year old.