The national chlorine shortage strikes Denver

First it was toilet paper, now it's chlorine.

What's happening: There's a nationwide chlorine shortage — and just before summer, when homeowners start prepping their pools.

• Why it matters: The shortage is not only expected to worsen in the coming months, but also to drive up the cost of the chemical used to keep pool water clean.

The backdrop: A few factors are fueling the problem, including a fire last summer at a major pool products plant in Louisiana that's halted all production until spring 2022.

• But the pandemic-induced wave of demand for above-ground pools is also to blame, experts tell Axios.

What they're saying: "Everybody and their momma last year bought above-ground swimming pools, and now they're all buying chlorine," said Justin Vashaw, owner of Denver-based Swimming Services and Supply, which is limiting chlorine purchases to existing customers to prevent from selling out.

• "It's certainly going to be an interesting summer," he said.

What else: Even people out of state — particularly in Texas — are calling Colorado for pool supplies, driving up demand further, said Amy Prieto, the manager at Crystal Clear Pools near Thornton.

• Other pool products like filtration pumps and above-ground pool liners also are growing scarce, she said.

The upside: Experts say there are alternatives to some of the hard-to-find products, including chlorine.

• Pool owners can turn to other water sanitizing supplies like saltwater chlorine generators, hydrogen peroxide and NST tablets — but consult a local pool expert first.

Of note: Denver officials tell Axios they aren't worried about the chlorine shortage because the city uses calcium hypochlorite to clean its public pools.