Mid-Summer Slump: How to Beat July Algae Blooms (And Prevent Them Until Closing)

Hey pool people, Al here! We’re deep into mid-July, the grill is hot, the sun is blazing, and your pool is probably getting more traffic than a highway at rush hour. But then it happens... you go out for a morning dip and spot that sneaky, slimy green tint creeping up the steps. Yep, algae just decided to crash your summer party.

Algae blooms during July and August are incredibly common, but they can be incredibly frustrating—especially when you test the water and see your system is actively producing chlorine. When chlorine alone isn't cutting it against stubborn summer blooms, it's time to shift strategies.

Here is the exact mid-summer routine I use at my own house to beat the heat, destroy the blooms, and keep the water pristine all the way to the end of the season.

Step 1: Trust the Test, Then Drop the Hammer

Before adding anything to your pool, grab your Test Kits & Strips to verify your baseline. If your water shows healthy chlorine production but algae is still taking hold, a standard shock might not be enough.

When this happens, my go-to first line of defense is a high-quality copper algaecide. Copper-based formulas are incredibly effective at aggressively disrupting the cellular structure of algae, knocking down active blooms fast without degrading in the harsh July sunlight. Browse our full selection of Pool Algaecides to find the right formula for your pool volume.

Step 2: Cruise Through August on Maintenance Doses

Killing the initial bloom is only half the battle. August brings sustained high temperatures and frequent summer thunderstorms, both of which introduce organic contaminants that feed new algae spores.

Once your pool is clear, don't just walk away! Keep up with a regular maintenance dose of algaecide every single week through August. This creates a continuous defense layer in the water, stopping new spores from multiplying before they can turn your pool into a swamp.

Step 3: The Late-Summer Pivot (Late August / Early September)

If you use copper algaecides or have heavy mineral content in your source water, those metals will slowly build up over the season. As the temperatures start to cool down in late August and early September, those suspended metals can react with your pool chemicals, potentially causing unsightly stains on your liner or steps right before you close up for the winter.

To prevent this, I always finish out the season by adding a high-quality metal control or "Metal Out" product. You can find these targeted stain-preventers in our Cleaners & Clarifiers collection. Adding this defense layer in late summer binds up any lingering copper or minerals, ensuring your pool stays stain-free and making your eventual spring opening infinitely easier.

Got questions about sizing the right dose for your pool? Drop a comment below, or stop by the shop to grab your summer supplies and talk pool care with Al!