Numbers Check and Advice Please

[KeriCarter]

I will be adding MA to lower PH per K-2006C tonight, but what should I attack after that? I put the numbers into the wheel for the first time, but I’m not exactly sure what that number tells me, other than it’s higher than desired. I really appreciate the help. I feel comfortable with the testing and basic numbers now thanks to you guys!

Crystal Clear
Temp 82
FC 5.2
CC 0
PH 8.0
TA 130
CH 130
CYA 40 (complete scrub and drain twice, was >400)
SI 1.1 (did I read this correctly?)

 

[dfwnoob]

FC 5.2

Save on reagents. Use 10mL pool water and 1 heaping scoop of DPD powder. From here, each drop of R-0871 equals .5 FC. So, if you use 10 drops, that's 5 FC.

If you aren't already, use the PoolMath app to track your results, and it'll give ballpark guidance on what is out of whack and what isn't.

 

[KeriCarter]

Save on reagents. Use 10mL pool water and 1 heaping scoop of DPD powder. From here, each drop of R-0871 equals .5 FC. So, if you use 10 drops, that's 5 FC.

If you aren't already, use the PoolMath app to track your results, and it'll give ballpark guidance on what is out of whack and what isn't.

Thanks! Just added the testing to PM.

 

[Texas Splash]

I would just lower the pH to about 7.6 or so. Always try to keep it under 7.8 to prevent scaling.

 

[duraleigh]

What does your water look like? Is that a pic of it?

 

[KeriCarter]

What does your water look like? Is that a pic of it?

Yes. Of course the kids and the dog were swimming and mucking it up when I took it. Before that it was as perfectly clear and sparkling.

 

[KeriCarter]

I would just lower the pH to about 7.6 or so. Always try to keep it under 7.8 to prevent scaling.

Thanks!

 

[duraleigh]

With all those good numbers and really clear water, I think you need to either go swimming or keep swimming. Dropping your pH into the 7's is the only adjustment I would make.

 

[KeriCarter]

With all those good numbers and really clear water, I think you need to either go swimming or keep swimming. Dropping your pH into the 7's is the only adjustment I would make.

That’s what I was hoping to hear. Thanks!
I’ll be reading about how to close it in a month or so. Time flies when you’re having fun.

 

[duraleigh]

Are those three handsome young men yours? Get them in the water fast! I sense rambunctious trouble if you delay

 

[mgtfp]

I will be adding MA to lower PH per K-2006C tonight, but what should I attack after that? I put the numbers into the wheel for the first time, but I’m not exactly sure what that number tells me, other than it’s higher than desired. I really appreciate the help. I feel comfortable with the testing and basic numbers now thanks to you guys!

Crystal Clear
Temp 82
FC 5.2
CC 0
PH 8.0
TA 130
CH 130
CYA 40 (complete scrub and drain twice, was >400)
SI 1.1 (did I read this correctly?)

Are you referring to the Watergram that comes with the Taylor test kit?

It is used to calculate the Calcite Saturation Index (CSI), which is measure for how saturated the water is with Calcium Carbonate. If CSI>0, then the water is oversaturated with Calcium Carbonate and it tends to scale surfaces. If <0, then the water is undersaturated and tends to be aggressive towards plaster/concrete. Best is to have CSI between -0.3 and 0.3, for a salt pool with SWG between -0.3 and 0.

CSI=1.1 doesn't look right with CH=130. Best to forget about that Watergram and use PoolMath to calculate the CSI. Just enable "Track CSI" in the settings, and then enter the test parameters as measured with the Taylor kit. For your water parameters you should get something like 0.23.

 

[KeriCarter]

Are you referring to the Watergram that comes with the Taylor test kit?

It is used to calculate the Calcite Saturation Index (CSI), which is measure for how saturated the water is with Calcium Carbonate. If CSI>0, then the water is oversaturated with Calcium Carbonate and it tends to scale surfaces. If <0, then the water is undersaturated and tends to be aggressive towards plaster/concrete. Best is to have CSI between -0.3 and 0.3, for a salt pool with SWG between -0.3 and 0.

CSI=1.1 doesn't look right with CH=130. Best to forget about that Watergram and use PoolMath to calculate the CSI. Just enable "Track CSI" in the settings, and then enter the test parameters as measured with the Taylor kit. For your water parameters you should get something like 0.23.

I didn’t think it looked right either. Thank you. I’ll just use Pool Math from here on out.

 

[KeriCarter]

Are those three handsome young men yours? Get them in the water fast! I sense rambunctious trouble if you delay

That is only part of the crew. We are over run by tiny swimming humans.
I tried saying we are done swimming for the day, this one decided the outdoor sink is a good alternative.

 

[pjt]

I’ll be reading about how to close it in a month or so.

You don't keep your pool open year round?

 

[KeriCarter]

You don't keep your pool open year round?

There is a propane heater. We havent been here through a winter so we haven’t used it yet. I wasn’t sure it would raise it to a comfortable temp. Does it use a lot of propane to heat it?
We swam almost 3 hours today with the water temp around 75. I’m not sure how much lower I could stand.
I haven’t figured out how to turn off the water features yet. That would likely help retain some daytime warmth.

 

[pjt]

Closing means stopping normal operations and configuration for cold temperatures: Closing Pool for Winter - Further Reading

In our climate, the vast majority of people keep their pools open year round.

 

[DrewLG]

Does it use a lot of propane to heat it?

FOR PROPANE ONLY, NOT NATURAL GAS:

A quick way to calculate the cost to raise your pool temperature by one degree Fahrenheit is:

Take the volume of your pool in gallons, multiply by your propane cost per gallon, then divide by 8820.​

​

A more accurate way, especially if you have an unusually efficient (or inefficient) heater, or if you also want to know how long it will take to heat the pool:

• Find your propane cost per gallon. Call that C.
• Find your heater's input rating, in BTU/hour, in the manual or on the manufacturer's website. Call that B.
• Find the heater's efficiency, also from the manual or website (if you can't find an efficiency number, use 0.80). Call that E.
• Multiply the volume of your pool, in US gallons, by 8.3 to find the weight of the water in pounds. Call that W.

Then:

• Gallons of propane to heat your pool one degree Fahrenheit = W divided by E, divided by 91500. Call that G.
• Propane cost to heat your pool one degree Fahrenheit = C times G.
• Time, in hours, to heat your pool one degree Fahrenheit = W divided by E, divided by B.

So for my Pentair MasterTemp 400 (input BTU/hour = 400000, efficiency = 0.84) and my pool (8000 gallons), with propane at $3.06/gallon:

C = $3.06
B = 400000
E = 0.84
W = 8000 x 8.3 = 66400

Gallons of propane per degree: G = 66400 / 0.84 / 91500 = 0.86
Cost per degree: $3.06 x 0.86 = $2.63 (the quick way at the top of this post would say $2.77)

Hours per degree = 66400 / 0.84 / 400000 = 0.20, so 5 degrees per hour.

[Edit: Updated with more precise values for BTU/gallon propane and pounds/gallon water. The difference isn't much -- only about 3%.]

 

[KeriCarter]

FOR PROPANE ONLY, NOT NATURAL GAS:

A quick way to calculate the cost to raise your pool temperature by one degree Fahrenheit is:

Take the volume of your pool in gallons, multiply by your propane cost per gallon, then divide by 9100.​

​

A more accurate way, especially if you have an unusually efficient (or inefficient) heater, or if you also want to know how long it will take to heat the pool:

• Find your propane cost per gallon. Call that C.
• Find your heater's BTU output in the manual or on the manufacturer's website. Call that B.
• Find the heater's efficiency, also from the manual or website (if you can't find an efficiency number, use 0.80). Call that E.
• Multiply the volume of your pool, in gallons, by 8 to find the weight of the water in pounds. Call that W.

Then:

• Gallons of propane to heat your pool one degree Fahrenheit = W divided by E, divided by 91000. Call that G.
• Propane cost to heat your pool one degree Fahrenheit = C times G.
• Time, in hours, to heat your pool one degree Fahrenheit = W divided by E, divided by B.

So for my Pentair MasterTemp 400 (BTU output = 400000, efficiency = 0.84) and my pool (8000 gallons), with propane at $3.06/gallon:

C = 3.06
B = 400000
E = 0.84
W = 8000 * 8 = 64000

Gallons of propane per degree: G = 64000 / 0.84 / 91000 = 0.84
Cost per degree: 3.06 * 0.84 = $2.57 (the quick way at the top of this post would say $2.69)

Hours per degree = 64000 / 0.84 / 400000 = 0.19, so around 5 degrees per hour.

You are amazing! Thank you so much for this. I have saved it in my notes.
10x