The guy from down the street drops by our house unannounced, just like he always does, and while he's there he looks out back and says: "Whoa, you've got a green pool! I mean, it's really green. Don't you ever clean it? That may be the greenest pool I've ever ."

The guy is pretty fast on his feet, so he is gone by the time I take a swat at him. But he's right. The pool looks like a 28,000-gallon vat of lime Kool-Aid. Which is galling, because just that very morning, like almost every morning, I was poolside with my handy-dandy All-In-One Pool Test Kit, playing Mr. Wizard.

Yeah, I know. I should hire a pool service. All my neighbors have pool services. I have friends in the pool-service business. But it's like this: When I was in college, I flunked two consecutive terms of organic chemistry-this is why I became a writer instead of a marine biologist-so, for me, performing all those chemistry tests to make sure the pool water is as pure as a baptismal font isn't just a chore, it's an act of redemption.

That very morning, the chlorine was right, the pH was balanced and the pool, I swear, was perfect. But what happened in the meantime was what happens most meantimes along the Gulfshore: It rained. It rained a lot. And whenever it rains, the pool turns green.

"It's a rain-borne algae that makes it do that," says Chuck, my man at the pool-supply store, where I no longer consider myself a customer but a sustaining member. Bob hands me a 12-ounce canister of algicide that sells for $19.95. That makes a total of $247,936, more or less, that I have handed over to Chuck since we've been doing business. When it comes time for my grandkids to go to college and they turn to me for help, I will hand them Mason jars and point them to the pool and say: "Go forth, fill up your jars and sell the water to pay for your tuition. I invested in that instead of stocks and bonds and real estate. It's now worth $7,000 a half pint."

I know who is to blame for all our green pools here in Florida. It's Canada. You know how Canada has been complaining for years about U.S. factories polluting the air and creating acid rain that falls on Canada? Well, the Canadians are getting even. The Canadian side of the border is now lined with massive algae factories. After the clouds dump acid rain on Canada, the Canadians shoot them full of algae and send them back south.

The sad result is good and decent people like me spending a quarter of our discretionary income making sure we don't contract cholera, plague, creeping eruption and whatever else you can catch from a green pool.

I even suspect that a Canadian cartel owns all the swimming pool stores. I can tell by the way Chuck sorta snickers whenever I walk in.

So I've stopped doing business with pool stores. I have contracted with the federal government, which has made me a great deal on the leftover defoliants and herbicides it used decades ago to denude much of Southeast Asia.

And soon my pool will be blue. It will be a shade of blue that can be achieved only if you make it impossible for the water to support any form of life whatsoever. Innocent toads will hop in and disintegrate. Wandering dogs will drink from it and howl. The guy from down the street will drop by. I think I'll invite him to go swimming.

Bob Morris, whose latest novel is Jamaica Me Dead (St. Martin's Press), was a finalist for the 2005 Edgar Allan Poe Award for best mystery novel.