Adding MA in front of returns

[yann]

Hi all

A little chemistry question.

Should I switch off my SWG when adding MA to the pool in front of a return?

I believe the chlorine concentration is quite high within the SWG, meaning it's quite high at the return.

What happens when highly acidic solution comes in contact with highly alkaline solution?

Thanks

 

[JoyfulNoise]

In reality, if you do the calculations, the FC concentration is not that high at all. By the time it comes out of the returns, it’s not even that far above target levels.

No need to turn off the SWG. I’ve been doing it that way for years and never once died....

 

[needsajet]

That's a helpful question because some people even worry about swimming near the return jets, but definitely not a worry. Each minute, just under a half gram of free chlorine is added to around 100,000 grams of water

A nice feature of the CCL test kit is the 5 disposable pipettes they include. To get comfort on this, you can use one of those pipettes to draw a sample from inside your return jet when it's bubbling, a couple mls at a time until you have your 10 mls for an FC test. With my pump on low speed, I get a rise of about 3 ppm (e.g. pool 5 ppm FC; water from return 8 ppm FC). I haven't tested pH this way, but I bet the difference is undetectable.