And, you know, what do you do in that situation and what causes that?

Well, the first thing is it probably scare you to death because you're you know, what goes through your mind is, oh, my God, I'm going to have to drain this pool and acid wash it for free.

You know, but so don't be don't be nervous about that.

It's OK.

There are some things you can do.

But the reason that it happens is that there's already a stain on the bottom of the pool and you didn't know it.

And usually the stain is copper and it's copper sulfate.

But what happens to a person who swims in a pool where there's no chlorine in the pool? Maybe they're in there for an hour.

But that's not the level that you recommend.

No, and it's not the level that's very effective, to be honest with you.

I think that 50 parts per million is the effective range.

But there is an obscure... detail from EPA and they ran a test and did a bunch of things and produced a 115 page report and ultimately it said that they wouldn't have any problem with 30 parts per million with a no level of concern of 150%.

So when you take You know, 30 parts per million times 1.5, you come up with 45.

So EPA is saying that it's okay to have 45, but there isn't anything that's going to measure 45.

So they agreed that 50 was okay.

What's the reasoning behind that level?

Why is trichlor so bad for the pool chemistry and balancing the pool?

Trichlor can be used successfully in a pool, but the problems that it creates when it becomes the sole source of sanitizer are monumental.

And I say monumental because when cyanuric acid level builds up, it slows down the chlorine.

We finally get so much cyanuric acid in the pool that it slows the chlorine down to where you actually need a lot more chlorine to keep the water safe.

And this is really important to understand.

For many years, cyanuric acid was thought of as just something that protected chlorine from being destroyed by sunlight.

Everybody said, well, it's no big thing if it builds up because it's just protecting the chlorine from sunlight, so it's not a big deal.

What could be a danger of switching from trichlor to Cal Hypo?

Um, but still, that percentage throws people off and they think, "Wow, this stuff is super strong, and I'm getting the chlorine, I'm not getting my money's worth out of it." What do you say to that kind of myth about that 99, 99% number that's thrown out there?

Well, first of all, there is no chlorine product that has 99% chlorine in it.

They, a- and they don't mean to deceive you, but, but there are a number of ways of stating different things, and part of it had to do with what happened many years ago when they started measuring chlorine.

The fact was that when you put chlorine gas in water, that it is 100% chlorine.

Correct? You put it in water, and so it makes some amount of free chlorine in the pool, and then they use that as a gauge to gauge everything else, how it compared to liquid chlorine.

I mean, to, uh, gas chlorine.

Well, the fact of the matter is you, chlorine gas is two atoms of chlorine.

Mm-hmm.

So copper does kill algae, right?

Yes, actually, copper at a low level kills algae.

At a little bit higher level, it kills bacteria.

So you can kill bacteria and algae with copper.

The problem is that there are a number of problems with doing that.

First of all, the level at which it kills algae and bacteria is right at the edge of the level where it causes stains.

So if you use it, you have to use a sequestering agent or a chelating agent in the water to prevent staining.

If it were to get to a certain level and stain the plaster or the pool surface, what's the best way to remove the staining of the copper on there besides draining it and acid washing the pool, which is a pretty harsh level? What about something that you can do while there's still water in the pool?

Why am I still getting algae in this pool? So you want to go over kind of this misunderstanding that happens out there?

For years, we used to just put in two to four parts per million of chlorine in the pool.

And that was supposed to be enough.

And then every summer, we all battled algae and put in algaecides and superchlorinate and shock once a week and all those kinds of things.

And we were doing stuff weekly to bring the chlorine level up to where it would kill the algae.

We started figuring out what the problem is.

And And about eight or nine years ago, I spent a few hundred hours studying what's going on in the pool.

You know, why is the pool cloudy? Why is there algae? So the runtime is a big deal, especially in the season.

What would be the main issue they should look at when they get a pool like that?

Well, you know, I think a pool that's using a lot of chlorine, you need to be a bit of a detective, if you will.

A lot of times it can be the homeowner's fault.

And it's something that either the homeowner is doing or one of the workmen around the house is doing, that they are cleaning something in the pool, they're blowing gas, When they mow the grass, the grass clippings are getting into the pool.

When the guy next door is fertilizing, you know, something is dropping into the pool.

They can also have a pool that's surrounded by vegetation or landscaping.

And that stuff is dropping into the pool.

What can I do to get rid of that? It seems like a permanent fixture in the pool.

used to have to do what was called a total dissolved

residue.

And what that was, was you actually took a volume of water that was measured very carefully to a volume or to a weight and then evaporated the water away from it.

And the residue that was left, you weighed it.

And that's what was called total dissolved residue.

Then they did the same test with pool water and called it total dissolved solids.

But nobody, nobody, nobody wanted to do that kind of a test.

And so for a non-salt pool, what would be the maximum TDS you can get to before you have to drain it? Because I know that a lot of people have problems, like the pool's not holding chlorine or it's getting weird, having weird problems.

But what is a good cyanuric acid level, and why is cyanuric acid even important to have in the pool?

Well, cyanuric acid, we used to think that cyanuric acid, all it did was protect chlorine from sunlight.

But cyanuric acid actually works as a buffer against the pH going down.

It controls the amount of chlorine that's available in the pool to kill things.

And the information has been around for a long time, but we haven't drilled down to the part of, you know, actual use practicality of it.

But the fact of the matter is, if you have any more than 30 parts per million of cyanuric acid in the water, 97% or more of your chlorine is bound to that cyanuric acid.

Now, it doesn't mean that it's not available.

That's

Learn more at swimmingpoollearning.com.

I get asked this all the time.

They say, how come the pH in my pool is going up all the time? My answer usually is, well, probably because your alkalinity is too high.

The alkalinity that's in the pool controls the amount of CO2 that off-gases out of the water.

I want everybody to understand that the control of CO2 off-gassing is alkalinity.

as the pool has too much carbonation in it already.

It's overcarbonated.

But you're also saying in the tech bowls in that the Cal Hypo does not raise the pH up in the pool, and it doesn't stay up, right?