Hi MD, I will do another set of tests in a week or two. Can you let me know how to do the diluted CYA test please? Also send me the instructions to test the salt. Appreciate itStick with 10ml sample for most every time you test
We only recommend using the 5ml sample when in the middle of slamming & testing a whole lot at high fc levels to help conserve reagents. But You’re not yet in that fight right now.
Were you able to do the diluted cya test?
I also have some more homework for you…
Do the Overnight Chlorine Loss Test at target fc levels FC/CYA Levels
If you pass, you can just exchange enough water to get the cya down to 70-80ppm & proceed with regular maintenance.
If you fail it’s SLAM Process time & that’s more easily accomplished with a bit lower cya level (50/60 ppm or below).
Pool Chlorine Level Keeps Dropping (Please help! Incurring astronomic costs in chemicals)
- Thread starter qsch1
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- Mar 5, 2020
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- Astral Viron V35
The diluted CYA test instructions are here:
www.troublefreepool.com
...and here, also with with a table of other mixing ratios should CYA be even over 200:
www.troublefreepool.com
Salt test instructions are here:
www.troublefreepool.com
Instructions for all tests you can find here:
www.troublefreepool.com
CYA - Cyanuric Acid Test
Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…
www.troublefreepool.com
...and here, also with with a table of other mixing ratios should CYA be even over 200:
Water Testing Instructions - Further Reading
www.troublefreepool.com
Salt test instructions are here:
Salt Test
The Salt Test is used to determine the concentration of sodium chloride (salt) in pool … Read more…
www.troublefreepool.com
Instructions for all tests you can find here:
Extended Test Kit Directions Archives
www.troublefreepool.com
- Jun 1, 2018
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+1. You need water in the vial or nothing happens. I had my own apart on the workbench trying to fix it because nothing happened when I put the pill in empty and pushed the button.
You mathed wrong. Use a 10ml sample, a full scoop and each drop is 1/2 FC.
90+ is sketchy to try and read.
Mix up a batch of 50/50 tap and pool water as your 'sample'. Proceed with the rest of the test as normal and double the result.
So I did the test this morning the regular one and it was still about 100. I am about to do the diluted CYA now. Is it correct that I add 7.5 ML to the bottle (50.50 tap and pool) and then add the agent another 7.5, for the total to be 15? Can I do it like that? The video and instructions say fill it to the upper mark but there are several marks.
- Mar 5, 2020
- 3,221
- Pool Size
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- Astral Viron V35
+1. You need water in the vial or nothing happens. I had my own apart on the workbench trying to fix it because nothing happened when I put the pill in empty and pushed the button.
You mathed wrong. Use a 10ml sample, a full scoop and each drop is 1/2 FC.
90+ is sketchy to try and read.
Mix up a batch of 50/50 tap and pool water as your 'sample'. Proceed with the rest of the test as normal and double the result.
Ok so I did it and it is right, the diluted test is now 50 and I doubled the result, which makes it 100 CYA. I did 7.5 half and half tap and pool, and 7.5 the mixing agent. I get the point of it now, as I realise now that it will give you an easier reading on the bottle.
On another note, I was wondering the relevance of CSI, which I never used, so I untagged it in the app? Let me know if that is fine please.
My results today, which I logged, were:
1.0 FC
1.0 CC (it rained a bit the last days so believe those values would have been slightly higher had it not)
8.5 PH
120 TA
100 CYA
5400 Salt (Wah) my first sat test (with the new kit), way above (what do you recommend min for salt 3400 or 3800?).
The water is super clear, but I have some flat, creeping algae.
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- Mar 5, 2020
- 3,221
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- 66000
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- Astral Viron V35
Which chlorine level were you maintaining over the last week's? Still having problems with chlorine not holding up?
An algae-free SWG-pool could be just maintained at CYA 100. But to go through a SLAM is a challenge.
An algae-free SWG-pool could be just maintained at CYA 100. But to go through a SLAM is a challenge.
I found out the problem with the pool was the cell, which was not producing properly or at all. Since the new cell, the pool cleared up and maintained, but the chlorine level is a bit low. I think this could be a combination of the CYA being high, and the solar driven pool pump, which does not allow the SWG to produce as much as the normal pump. I did not check the chlorine levels since the last time about 4 weeks ago, as the pool was very clear, but it had a little bit of algae which we were able to control.
- Mar 5, 2020
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- Astral Viron V35
If you want to have a chance with CYA that high you need to be diligent with FC being kept above min at all times, try to stay within the target range:
Once you have algae, you will not get rid of it by maintaining target FC, you will have to follow the SLAM Process. And this is a challenge at CYA 100:
You'd be better of draining some water to reduce CYA should you have to SLAM. Especially with your limited access to test reagents.
High CYA is not reducing FC as such. The problem with high CYA is that high FC levels are required to actually have a sufficiently high amount of hypochlorous acid (HOCl), which is the form of FC that is actually sanitizing your pool and killing algae - the rest of what shows up as FC is less efficient hypochlorite ion and absolutely non-sanitising chlorinated cyanurate (i.e. chlorine attached to CYA, that's your reservoir of UV-protected chlorine that still shows up as FC, but has no sanitising or oxidising powers).
Once FC is too low, algae creeps in and creates additional chlorine demand, which can be huge. I suspect that's what you are dealing with.
An Overnight Chlorine Loss Test would be a good starting point from here to assess the situation.
Once you have algae, you will not get rid of it by maintaining target FC, you will have to follow the SLAM Process. And this is a challenge at CYA 100:
You'd be better of draining some water to reduce CYA should you have to SLAM. Especially with your limited access to test reagents.
High CYA is not reducing FC as such. The problem with high CYA is that high FC levels are required to actually have a sufficiently high amount of hypochlorous acid (HOCl), which is the form of FC that is actually sanitizing your pool and killing algae - the rest of what shows up as FC is less efficient hypochlorite ion and absolutely non-sanitising chlorinated cyanurate (i.e. chlorine attached to CYA, that's your reservoir of UV-protected chlorine that still shows up as FC, but has no sanitising or oxidising powers).
Once FC is too low, algae creeps in and creates additional chlorine demand, which can be huge. I suspect that's what you are dealing with.
An Overnight Chlorine Loss Test would be a good starting point from here to assess the situation.
This makes total sense. I can add a bit of fresh water to the pool in the meantime, try to get the level down slowly, and try to keep the algae maintained. We just scrubbed it today, and it looks mostly gone, but I guess it will return. let me sleep on it and think a bit Thank you very much for your help will connect soon and read how to do the overnight chlorine loss test if it is not too complicated?
Couldn't be easier. It simply takes the UV loss out of the equation. If you lose FC overnight, algae is brewing. You want an 8 or so FC after sundown and 1 ppm or less loss right before sunrise.
Protip: if you leave the pump running all night, you won't have to wake up a half hour earlier than sunrise to mix the water well.
- Jun 1, 2018
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This is what I mentioned above: I have a solar half horsepower driven pump, it works only when the sun is up between 8 - 5 (more or less).
I read that earlier and forgot it when the thread continued.
Give it a good stir with a paddle or the pool brush in the morning before testing. I think waiting for the pump to be able to run would make it more likely you fail.So let me get this straight, to do the overnight pool loss test I have to check the FC late in the evening, then in the morning again? I should mix it a bit with the pool brush before doing the test in the morning? Bear in mind that the FC result from yesterday morning was 1.0 - this was early in the day before the pump would have been running fully. And I need to do all of this before the SLAM process?I read that earlier and forgot it when the thread continued.
- Jun 1, 2018
- 16,027
- Pool Size
- 26000
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- Vinyl
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- Hayward Aqua Rite (T-15)
Both tests should be done in the dark - the pm one doesn’t have to be late at night, just after the sun is gone.
In the am set an alarm for 30 min before sunrise.
The point is to eliminate uv as an fc consumer meaning that if fc is consumed during that period the culprit is organic.
The pool water needs to be properly mixed for both tests (pm& am) to ensure accuracy. Its much easier to just leave the pump running overnight if possible.
You want the fc level to be in target range when starting the test.
FC/CYA Levels
You can just go straight to the
SLAM Process if you have visible algae. Those pictures look like visible algae.
The Overnight Chlorine Loss Test is really for seeing if you have a problem when its not actually visible.
It is also the last of the 3 criteria that you must pass to end the slam process to prove that you’re algae free when the pool looks clear. So you will need to do it eventually & any other time you think there may be a problem brewing.
*It is much more practical to perform the slam process with a cya of 60/70 than at a cya of 100 so I would suggest that you replace 40% of your water before starting slam.
- Mar 5, 2020
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- Pool Size
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I would not do an OCLT at an FC of 1. Any observable loss (i.e either 0.5 or 1) I would consider a fail at this level - that's a loss of either 50% or 100%. Even though by reading the OCLT criteria black and white they would a pass. The OCLT criteria where not defined for this.
Raise FC before doing an OCLT, anything else I consider just a waste of your previous reagents.
Raise FC before doing an OCLT, anything else I consider just a waste of your previous reagents.
- Mar 5, 2020
- 3,221
- Pool Size
- 66000
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- Plaster
- Chlorine
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- Astral Viron V35
I would go as far as claiming that with FC 1 at CYA 100 it would be very unlikely to not have algae.
Ok, that all makes sense, I am going to try and get my CYA down, I already added more fresh water today (about 10% so far). What about all those fancy algae-removal supplements? Will the CYA gradually go down over time?
Thanks to all of you, I agree that there is no sense in slamming until the CYA is lower. I added some water to the pool (about 10%), but I don't really want to throw any out as long as the pool is clear. I am on a small island where we have to be fully self-sufficient with our own rainwater supply (I know, annoying). Will the CYA come down on its own after a while? Also, please let me know how the algaecide supplements work and if it makes sense to throw any of these in? I have attached an image. At this point in time I told the gardener that he needed to scrub any algae regularly in order to control it for the time being.
