PST and swimming pool

[squidguy]

This may be a stupid question but...

Got some new PST cylinders and was wondering if the zinc coating would react to chlorine or bromine in a pool????

Thanks for your words of wisdom!

 

[Dee]

I've been using a PST HP65 tank in pool sessions for 2-3 years with no drastic effects. The coating has gotten just a tad darker over the years but I can't say whether it's from chlorine, salt water, ozone, whatever....

 

[cybordolphin]

I would personally check the PH and Alkalinity before going in.

You may find that the pool guy has the PH and or Alkalinity extremely acidic. I have seen pools that the pool guy has etched the chrome ring around the pool light (now a nice BLACK color), overnight.

Most pool guys are flakes (I said most). A very high level of chlorine can also cause etching. But it has to be VERY VERY high. And this will generally mean the rest of your equipment will suffer first (wetsuit, BC, etc)

It is very common to see PH and Alkalinity levels way out of line.
PH should not be below 7.6 and the Alkalinity should be between
90 ppm and 110 ppm (110 ppm is preferred)

If you jump into a pool that has a PH of below 7.4 or an Alkalinity below 70 ppm, you are absolutely damaging all the metal parts on your rig. You would be surprised how often you will find this the case.

 

[sheck33]

cybordolphin once bubbled...
I would personally check the PH and Alkalinity before going in.

You may find that the pool guy has the PH and or Alkalinity extremely acidic. I have seen pools that the pool guy has etched the chrome ring around the pool light (now a nice BLACK color), overnight.....................

If you jump into a pool that has a PH of below 7.4 or an Alkalinity below 70 ppm, you are absolutely damaging all the metal parts on your rig. You would be surprised how often you will find this the case.

If a pool is acidic enough to etch metals or really damage equipment quickly would you want to be swimming in it??
I think my eyes are more sensitive to pH then my cylinder is.
And there better not be much bromine in a pool, bromine and chlorine also are very very nasty elements.

 

[cybordolphin]

Yes.... a low PH will effect your eyes. Most people assume the eye irritation is due to chlorine.

I have many times seen a pool light chrome ring ruined in a few hours, as well as pool pump impellars desolved down to almost nothing (brass).... due to acid being dumped into the pools incorrectly.

The etch may not appear right away though... but once the damage is done it is just a matter of time for the etched metal to come off.... where it will then be more noticeable.

 

[madmole]

Pure water has a PH of 7 so It cant be bad to swim in it
as apposed to 7.4. Also its a logrythmic scale so a PH of 5 is 10 times worse than a PH of 6 and 100 times worse than 7

Also PH is a measure of alkalinity (or Acidity), PPM must be a measure off something else (salinity?, BOD?, Carbonates?)

Marine salt water has an alkalinity of 8.4 at an average density of 1.026-1.028and a calcium level of about 400ppm. Pure Water has an PH of 7. Must take my PH meter to the pool and see what it says

 

[sheck33]

madmole once bubbled...
Pure water has a PH of 7 so It cant be bad to swim in it
as apposed to 7.4. Also its a logrythmic scale so a PH of 5 is 10 times worse than a PH of 6 and 100 times worse than 7

Also PH is a measure of alkalinity (or Acidity), PPM must be a measure off something else (salinity?, BOD?, Carbonates?)

Marine salt water has an alkalinity of 8.4 at an average density of 1.026-1.028and a calcium level of about 400ppm. Pure Water has an PH of 7. Must take my PH meter to the pool and see what it says

PPM is a measure of concentration of a substance, it stands for Parts Per Million. 400ppm means 400 calcium ions for every million water molecules.

 

[cybordolphin]

PH and Alkalinity are tested seperately/differently.

We also are not talking about "pure" water. A PH of 7 would probably be ok. But I would not want it any lower for sure.

There are lots of elements introduced into pool water that effect the PH, and Alkalinity.

It would be nice if a pool could/would maintain a perfect PH balance.

If you go to jump into a pool that has either lots of etching or lots of scale (feels like ROUGH sandpaper), its a good indicator that likely the pool is not/has not been well maintained/balanced, and likely you will find the PH and Alkalinity way out of balance.

Once again.... I would not put my gear into a pool that has a very low PH OR Alkalinity.

 

[sheck33]

madmole once bubbled...


Also PH is a measure of alkalinity (or Acidity), PPM must be a measure off something else (salinity?, BOD?, Carbonates?)

pH is NOT a measure of alkalinity
pH is a measure of the concentration of hydroxyl or hydrogen ions. If the pH is high the solution has a lot of hydroxyl ions and is very basic, if the pH is low there are a lot of hydrogen ions and the solution is acidic. A high pH does however NOT imply that the solution has high alkalinity nor does a high alkalinity require a high pH.

alkalinity is a measure of the BUFFERING ability of a solution, in other words how much acid can i add to the solution without significantly changing the pH.

Thre are 3 kinds of alkalinity:

carbonate (CO32-), bicarbonate (HCO3-), and hydroxide alkalinity (OH-). Total alkalinity is the sum of all three kinds of alkalinity

If i jump into a pool i dont care what the alkalinity is, what i want to know is what the pH is!

 

[TCDiver1]

Ch-101 on a scuba board. Thanks sheck33, you dredged up some wonderful memories of organic Chem. for me. Memories it took me years to bury!:book: