PoolMath Units Question

[jseyfert3]

At the bottom of the page, for Effects of adding chemicals, is the oz weight or fl oz?

I've been using PoolMath for my new spa that I just got set up a couple days ago. This morning, my fc was at 1.8. I wanted to bring it up to 5. I'm still using dichlor, and it said to add 0.2 oz by weight. I generally use a small pocket gram scale for small amounts like this, so I can certainly get much finer than 0.2 oz. At the bottom, I can check how added 0.20 oz will affect the pool (raise FC by 2.9) or 0.22 oz (raise FC by 3.1). But it doesn't say if it's weight or volume oz, or if it switches between them based on what chemical you select.

 

[JoyfulNoise]

PoolMath has some intelligence built into it. If you select a chemical that is typically a solid, the answer is in measured weight. If you select a chemical that is a liquid typically, it’s by measured volume.

It’s more obvious if you use metric units as the metric system does not use the same naming scheme for weights and volumes.

 

[jseyfert3]

Oh thanks. I didn't realize you could switch units on the calculator. I missed that.

 

[cfherrman]

Off topic, but how are those inflatable hot tubs?

 

[LinCa]

Oh thanks. I didn't realize you could switch units on the calculator. I missed that.

ARGH! You're not the only one who missed that! Thanks for bringing it to my attention - I have been busily recalculating everything manually into metric.

 

[JoyfulNoise]

ARGH! You're not the only one who missed that! Thanks for bringing it to my attention - I have been busily recalculating everything manually into metric.

Both the App and the website allow you to setup your pool using either US, Imperial or Metric units.

 

[jseyfert3]

Off topic, but how are those inflatable hot tubs?

Better than no hot tub!

I'll probably post some of my detailed thoughts in their own thread at some point, but in short:

• Heater is underpowered. Limited to 1300 watts since the tubs have to be able to run on a 15 A, 120 V circuit. Takes a while to heat up (~ 2 days for me), and even without bubbles can't hold temp with the cover off. We usually get in around 99-100 °F (don't like to sweat) and in an hour it'll be at 96. Garage is around 45-50 °F right now though and it's sitting on concrete. Probably improved with foam board underneath and higher ambient temps.
• Bubbles are worthless. There aren't any jets (though apparently some more expensive models can have jets), just a bubble ring. They don't have a massaging function, tend to spash when you're sitting in the pool (not good in a garage), and cool the tub very rapidly (it'll take it from 99 to 94 in half an hour when I use them to aerate the tub). So we keep them off. On the plus side they are great for aerating the tub to raise pH, help get out CC's, or for the acid/aeration method to lower TA.
• No seats, though the bottom isn't hard. I'd like to be able to recline in a nice seat.
• No jets.

Otherwise, for soaking in hot water, it works fine. And they are much, much cheaper than a "real" hot tub. Only had it two weeks so far though.

 

[mdogan]

i think pool calculator was created by Jason. There was similar subject and he answered chlorine calculation by weight in the tool.

That is my biggest concern since if by weight we are wasting tons of liquid chlorine unnecessarily since by fl oz difference is alot.

for my case, 12000 gallons pool

by weight 16 oz.....on the scale cup equal around 12 fl oz.

so 32 oz by weigh equal 24 fl oz on scale cup.

this 2 numbers is really too much different, and still I'm not sure....

have a great weekend all of you