when is it not safe to swim in the pool

[waterbear]

I would not swim in a pool that did not have a proper residual sanitizer level in it! Also, I would not swim in a pool with an algae bloom as some forms of algae can produce toxins.

[PhantomAndy]

For the typical pool - I'd say any Cl level below 8-10ppm (preferably in the 3-5 range) is safe.

I don't think swimming in a green pool would hurt you, unless you drank the water. That said - I would imagine it's probably pretty hard to swim in a pool without getting at least a little water down your throat.

My preference, to be on the safe side is to ensure you have 2-5 ppm free Cl, proper pH (7.2-7.5) and water that is clean and clear. If the chemicals aren't right it's probably not going to be clear anyway.

[Brock]

We just refilled our pool and hot tub and the CL was up at 27. My wife really wanted to go in the hot tub so I heated it up and we jumped in. We did rinse off after and I don't think I would want our kids in water above 10. I personally have been in our pool when it was about 50 and I am still pretty normal If in doubt about high CL levels rinse before and after, I have found you soak up less CL smell if you’re already wet and obviously rinsing after helps a lot.

[dalparadise]

The "chlorine smell" is chlorine reacting to things in the water. Thus, if you rinse off before going into the pool, sweat, dirt, etc. on your skin will be rinsed off and will not cause as much reaction with the chlorine in the pool.

Pool water -- even really high chlorine levels -- where there is no Combined Chlorine (reactive chlorine) present has only a faint smell. The "chlorine smell" most people remember from being kids at public pools is the result of a lot of funky stuff in the water causing the chlorine to react.

[CarlD]

I absolutely would NOT let my kids in pool water that was at all green. This is not a lake that's part of the environment, with water flowing in and out--it's more like stagnant water.

Chlorination does more than kill algae--it kills and neutralizes other stuff. The MOST important thing, to my mind, that chlorine does is sanitize fecal matter. Yeah, poop. Every person who enters your pool leaves an infantisimal amount--or more. Gross but true. Proper chlorination renders that sanitary and inert very quickly. If you have algae, you don't have that sanitation. Need I say more?

[tmmort]

I absolutely would NOT let my kids in pool water that was at all green. This is not a lake that's part of the environment, with water flowing in and out--it's more like stagnant water.

Chlorination does more than kill algae--it kills and neutralizes other stuff. The MOST important thing, to my mind, that chlorine does is sanitize fecal matter. Yeah, poop. Every person who enters your pool leaves an infantisimal amount--or more. Gross but true. Proper chlorination renders that sanitary and inert very quickly. If you have algae, you don't have that sanitation. Need I say more?

Great post! Should be a sticky.