United Chemical
Login
$0.00 0

Cart

No products in the cart.

Continue shopping

How to Get Rid of Black Algae in your Swimming Pool

Black algae is a type of bacteria that can be really tough to kill and control in your pool. Here we show you had to kill black algae fast and how to prevent it from coming back.

How to at a glance

4

Steps

30

minute(s)

Step by Step

Step
1

Add Swamp Treat™

Add one (1) poubd of Swamp Treat™ per 20,000 gallons of pool water.

Step
2

Brush

Brush the walls of the pool. You’ll need to get as much of the black algae off the surface as possible, so some scrubbing might be needed.

Step
3

Shock

Add approximately 2 pounds/gallons of shock per 10,000 gallons – cascading it around the pool.

For color/painted/vinyl surfaces using trichlor to shock: don’t allow the granules to sit on the surface, or it could lead to bleaching.

Step
4

Filter

Set your system back to filter, and turn the pump on. Allow to filter for 24 hours

Related How-Tos

Pool Algae

How to Clean a Green Swimming Pool Fast

Pool Algae

How to get rid of Mustard Algae in Swimming Pools

Pool Maintenance

How to Close a Pool for Winter

Pool Maintenance

How to Open Your Swimming Pool for Spring

Pool Algae

How to Treat White Water Mold in Swimming Pools

How to Kill Pink Algae in your swimming pool

Related Guides

The Ultimate Guide to Pool Algae: Identification, Biology, and Behavior

To the naked eye, a swimming pool is a simple vessel of water. But biologically, it is a fragile ecosystem constantly under siege. While you view your pool as a place to relax, nature views it as a perfect niche: warm, wet, and rich in nutrients. When water turns cloudy or spots ...

The Ultimate Guide to Pool Filter Maintenance: Chemistry, Cleaning, and Efficiency

The modern swimming pool is a complex hydraulic system, but if the pump is the muscle, the filtration unit is the “Hydraulic Heart.” While sanitation systems (like chlorine or salt generators) are responsible for killing pathogens, the filter is tasked with the physic...

The Ultimate Guide to Salt Water Pools: Chemistry, Care, and Reality

The widespread adoption of saltwater pools is one of the most significant technological shifts in modern aquatic facility management. This transition shifts the locus of chemical manufacturing from centralized industrial plants to the point of use, fundamentally altering the oper...

The Ultimate Guide to Pool Water Balancing: Chemistry, Care, and The Hamilton Index

Owning a pool should be about relaxation, not a daily struggle with test kits and chemicals. Yet, many homeowners and pros alike find themselves trapped in a cycle of “yo-yo” chemistry—constantly adjusting pH down, only to watch it bounce back up days later. This guid...

Related Articles

The “Pool Smell” Lie: The Science of Chloramines and Breakpoint Chlorination

We have all experienced it. You walk into an indoor hotel pool or a public facility, and you are immediately hit with that sharp, stinging chemical odor. Your eyes start to water. You instinctively think, “Wow, they must have put way too much chlorine in this pool.” T...

The Cost of Recovery: The Economic Case for Preventative Algicides

In the pool industry, there is a common resistance to the use of “extra” chemicals. When a pool pro or a store clerk suggests a preventative algaecide (like our No Mor Problems®), some customers hesitate. They look at the bottle and think, “Why should I spend mo...

The Phosphate Panic: Do You Really Need to Worry About Phosphate Levels in Your Pool?

There is debate in the industry regarding how important phosphate levels are in pools. One side says using phosphate removers is an integral part of maintaining an algae free pool, while the other says it’s a total waste of money. In this article we break down the science to give...

Sodium Bromide Algaecide: The Science of Killing Pool Algae

Is your pool turning green despite your best efforts? If you are fighting stubborn blooms—especially resistant strains like mustard algae—standard chlorine shock might not be enough. At United Chemical, we believe in solving problems with science, not guesswork. Many pool owners ...

The Pool Chemistry of Cyanuric Acid:  Understanding Equilibrium and Sanitizer Efficacy

Is Cyanuric acid both a blessing and a curse? It helps stabilize chlorine so it burns more slowly, but too much is thought to reduce the efficacy of your sanitizer. Or does it? Here we break down the science behind one of the most misunderstood chemical compounds in swimming pool...

Your Partner in Perfect Water (And Savings)

At United Chemical, we believe what we do helps make people happy. Join our community to receive expert pool care education, helpful tips, and exclusive product updates. As a welcome gift, we’ll send you a code for 10% off. Let us help you succeed in keeping your pool crystal clear.
United Chemical
(800)524-5550
Mailing:
P.O. Box 429
Piru CA 93040
Shipping:
3741 E. Telegraph Rd.
Fillmore CA 93015

Our Guarantee

All United Chemical products are backed by a 100% Performance Guarantee: if a product doesn't do what it says it will then we'll fix it for free and/or give you a full refund.
©2026 United Chemical Corporation. All rights reserved.