Math problem

[jimbethesda]

I'm trying to figure out how much calcium my pool will add daily due to evaporation and re-fill. Here are the variables:

Tap water 80ppm
I estimate I'm losing 167 gallons per day
My pool is 20,000 gallons

How many ppms will my calcium increase per day?

Do you take 167/20,000 = .00835 and multiply that times 80ppm? Or am I way off?

 

[JamesW]

169 gallons of water at 80 ppm calcium contains 2 oz calcium chloride

In 100 days, the calcium hardness will raise by 68 ppm.

In one day, the CH will raise by 0.68 ppm.

 

[Newdude]

How many ppms will my calcium increase per day?

So I think I was able to reverse engineer it with a ppm calculator.


PPM = Weight/Gallons X 119,826.427.

80= Weight / 1 × 119,826.427

0.000667632 lbs CH per gallon

0.11149 lbs CH added per 167 gallons of fill
+ .6 CH.

GAH !!! James beat me.

 

[jimbethesda]

169 gallons of water at 80 ppm calcium contains 2 oz calcium chloride

In 100 days, the calcium hardness will raise by 68 ppm.

In one day, the CH will raise by 0.68 ppm.

Thanks!

 

[jimbethesda]

169 gallons of water at 80 ppm calcium contains 2 oz calcium chloride

In 100 days, the calcium hardness will raise by 68 ppm.

In one day, the CH will raise by 0.68 ppm.

So it looks like we came up with the same answer, but took different approaches. .00835 * 80ppm = .67 ppm per day.

 

[mgtfp]

PPM = Weight/Gallons X 119,826.427.

80= Weight / 1 × 119,826.427

0.000667632 lbs CH per gallon

0.11149 lbs CH added per 167 gallons of fill
+ .6 CH.

You guys are messing with my head with your gallons and ounces...

 

[Newdude]

You guys are messing with my head with your gallons and ounces...

Sorry mate. We'd never leave you out on purpose. . An ounce is 1/24th of a Foster's. You need about 5 Foster's per gallon.

 

[mgtfp]

Sorry mate. We'd never leave you out on purpose. . An ounce is 1/24th of a Foster's. You need about 5 Foster's per gallon.

Thanks for that. This puts things in perspective.

Personally, I had to run a quick fact check if the Foster's unit system is compatible with the systems that I am more familiar with, but volume wise they all seem to line up within certain tolerances. Interestingly, once you get to these levels that you call "gallon", the differences between the various systems get more and more negligible and everything kind of blurs into each other.

 

[JoyfulNoise]

@Newdude has been appreciating the subtleties of imperial and SI units lately … ask him how cold his beer needs to be so that it doesn’t matter if it’s °F or °C … then again, if it’s that cold, he won’t be caring much about anything …

 

[mgtfp]

if it’s that cold, he won’t be caring much about anything …

I guess so. I also assume that he prefers to drink his beer and not eat it.

 

[JamesW]

You guys are messing with my head with your gallons and ounces...

Ounces weight or ounces volume?

 

[mgtfp]

Ounces weight or ounces volume?

Now you're just piling on...

 

[an1vrsy]

This is the brainiacs thread. I was lost after the first post. TFP methodologies are to use the 10 mL sample size. To calculate the CH, we have to use the 25 mL sample size. I understand that. This math thread, not so much.

 

[midlifecrisis]

This is the brainiacs thread. I was lost after the first post

I'm still trynna figure out what a calcium is... based on thread context I've got to believe it's a micro-brew?

 

[JamesW]

Here's a good tip:

All metric and standard units are the same at -40.

-40 degrees Fahrenheit is -40 degrees Celsius.

-40 pounds is -40 Newtons.

-40 feet is -40 meters etc.

 

[JamesW]

Actually, I'm against all negative and imaginary numbers.

You can't have a negative amount of anything or the square root of -1 x anything.

When I was young, we didn't even have units; all we had was some, none, more, and less.

We didn't have all of these fancy units so that we could describe everything exactly.

 

[JoyfulNoise]

e^{i π} = -1

 

[mgtfp]

e^{i π} = -1

I think this is the most beautiful equation in existence.

 

[mgtfp]

All metric and standard units are the same at -40.

From my point of view this is absolutely correct, because metric units are standard units.

 

[JoyfulNoise]

I think this is the most beautiful equation in existence.

Unless you’re a physicist, then it -

α = q_e² / 4πε₀ħc