CYA (Stabilizer) | Minimum FC | Target FC | SLAM |
20* | 2 | 3-5 | 10 |
30 | 2 | 4-6 | 12 |
40 | 3 | 5-7 | 16 |
50 | 4 | 6-8 | 20 |
60 | 5 | 7-9 | 24 |
70* | 5 | 8-10 | 28 |
80* | 6 | 9-11 | 31 |
90* | 7 | 10-12 | 35 |
100* | 8 | 11-13 | 39 |
New Test Results: 10:30 am | Pool 83 degrees | Air 82 degrees
FC = .5 (CC = 0, TC = .5) (yesterday = 1.0)
pH = 7.5 (same)
TA = 90 (yesterday = 100
CH = 425 (yesterday = 450)
CYA = 120 (used 50/50 pool/tap water, doubled result) (yesterday = ? 110)
CSI = -0.10 (yesterday = 0.07)
I guess I'm glad the CYA isn't higher as I thought it would be. Is CYA stored in the plaster and pipes?
Also, I just want to thank you all for your help with this. I really appreciate it!!
Edited to add:
I have Blue Whale Shock Chlorinator / 12.5% sodium hypochlorite
Am I aiming for the FC at 11 - 13 in this chart?
CYA (Stabilizer) Minimum FC Target FC SLAM
20* 2 3-5 10 30 2 4-6 12 40 3 5-7 16 50 4 6-8 20 60 5 7-9 24 70* 5 8-10 28 80* 6 9-11 31 90* 7 10-12 35 100* 8 11-13 39
I'm guessing 13-15, with a minimum of 10, extrapolating from the rest of the chart.New Test Results: 10:30 am | Pool 83 degrees | Air 82 degrees
FC = .5 (CC = 0, TC = .5) (yesterday = 1.0)
pH = 7.5 (same)
TA = 90 (yesterday = 100
CH = 425 (yesterday = 450)
CYA = 120 (used 50/50 pool/tap water, doubled result) (yesterday = ? 110)
CSI = -0.10 (yesterday = 0.07)
I guess I'm glad the CYA isn't higher as I thought it would be. Is CYA stored in the plaster and pipes?
Also, I just want to thank you all for your help with this. I really appreciate it!!
Edited to add:
I have Blue Whale Shock Chlorinator / 12.5% sodium hypochlorite
Am I aiming for the FC at 11 - 13 in this chart?
CYA (Stabilizer) Minimum FC Target FC SLAM
20* 2 3-5 10 30 2 4-6 12 40 3 5-7 16 50 4 6-8 20 60 5 7-9 24 70* 5 8-10 28 80* 6 9-11 31 90* 7 10-12 35 100* 8 11-13 39
What do you suggest for chemicals/amounts & order of application?We can help you with adding Chemicals. Retest your CYA and post a current battery of tests and we can go from there.
You can use the Old Poolmath link at the bottom of the page to determine correct FC levels for CYA levels over 100.Am I aiming for the FC at 11 - 13 in this chart?
Now that's an interesting idea I've never heard mentioned...thanks.I'm thinking if you want to get a good solid exchange heat the pool pretty well so the exchange will have a greater temperature split.
Great idea about the rain suggestion...thank you.With the approved CYA test, any number over 100 is in question and should not be trusted. But let me do some math to help you. Lets say that your pool was 9000 gallons, and your CYA was 200. If you drained 2/3, down to 3000 gallons, those 3000 gallons would still have a CYA of 200. But if you add 600 gallons back to fill your pool, now the filled pool would be down to 67.
Do with a 2/3 drain, using the drain and then refill technique (and this is important to differentiate), the best you can do is to take your CYA down to 1/3 of its original value. And due to test accuracy, lets just say that you thought it was 200. It might have been 400 in reality.
So the fact that you are around 100 still seems fair, even if depressing.
When you say exchange, were you simultaneously draining and filling, simultaneously draining and filling with a tarp separating the new and old waters, or did you drain down, and then fill. I ask, because there is a huge difference in outcome.
The problem with simultaneously draining out water while adding in new water without a tarp separation, is that you are not only draining old water with high CYA, you are draining out new water as well. There are too many factors for me to do the math, but as a quick guess, simultaneous non-tarp actions would take my math example above, and rather than getting rid of 2/3 of your CYA, you might only get rid of 1/2 or 1/3, so your CYA might only go down from 200 to 100 or 133.
If you are going to use rain to exchange water, the best way to do this is like this. If you think that you will get 2" of rain in a week, drain your pool down 2" before any rain comes down. Then let the rain fill it back up. This provides the biggest bang for your buck so to speak.
Not true. And not read on this forum.I read somewhere (maybe in this forum) that CYA is retained in the plaster and pipes...not sure if true or not, but wouldn't doubt it.
Good to know. So basically CYA is a water only problem.Not true. And not read on this forum.
I would say yes.With these numbers, do I just need to add chlorine (2 gallons?)?
FC = .5 (CC = 0, TC = .5) (yesterday = 1.0)
pH = 7.5 (same)
TA = 90 (yesterday = 100
CH = 425 (yesterday = 450)
CYA = 120 (used 50/50 pool/tap water, doubled result) (yesterday = ? 110)
CSI = -0.10 (yesterday = 0.07)
Now that's an interesting idea I've never heard mentioned...thanks.
I'm not sure if you found the answer to this.. You can add chemicals in any order really the only rule of thumb is don't add MA and Cl and the same time, separate them by 30 min or so. Based on your numbers you only really need to add Cl and if you are planning on another water exchange your CH will go down by the same percentage as your CYA.I think my plan today is this:
Do the diluted water CYA test
Depending on results, I may drain some more water. (I'm expecting a very high reading)
Then chemicals...BUT I need help with the order in which to add them.
Do be ware of the risk involved in using a tarp. Children, pets, etc must be banned from the area. Constantly monitoring the pool area is required. We in general do not recommend this method due to the risks.That's where the tarp method comes in since it imposes a physical boundary between the two.