Pool Problems

Know Your Algae

Green Algae

The most common variety of pool algae. Fortunately, it’s also the easiest to deal with.

Yellow Algae

You’ll see this on surfaces – it appears as a yellow or mustard-colored dust. It’s more resistant to chlorine.

Black Algae

Attaches to surfaces, grows roots into plaster and forms a protective slime layer over itself.

Pool Problems

Know Your Algae

Green Algae

Yellow Algae

Black Algae

Black Algae

Black Algae

Never deal with algae again.

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Never deal with algae again.

Sign up below to receive your free treatment plan for black algae.

It’s not your fault.

Chemical interactions in your pool are complex as shown below. WaterGuru SENSE along with advice in the WaterGuru app can help.

  • Most chlorine is bound to cyanuric acid (aka stabilizer) and it is the unbound active chlorine that kills/prevents algae and provides disinfection.
  • Stabilized chlorine products, such as Trichlor tabs and pucks, increase the cyanuric acid level over time thereby lowering the active chlorine level so algae can then grow faster than it is killed.
  • Phosphates are an essential nutrient for algae growth so keeping phosphates low helps prevent algae.

It’s not your fault.

Chemical interactions in your pool are complex as shown below. WaterGuru SENSE along with advice in the WaterGuru app can help.

  • Most chlorine is bound to cyanuric acid (aka stabilizer) and it is the unbound active chlorine that kills/prevents algae and provides disinfection.
  • Stabilized chlorine products, such as Trichlor tabs and pucks, increase the cyanuric acid level over time thereby lowering the active chlorine level so algae can then grow faster than it is killed.
  • Phosphates are an essential nutrient for algae growth so keeping phosphates low helps prevent algae.

Kill your black algae

Step 1

Visually identify the type of algae you’re dealing with. Then, take a reading with WaterGuru TEST (or take a sample to your pool store) so you know your cyanuric acid (CYA aka stabilizer or conditioner) level to know how much chlorine or other products you will need to use.

Step 2

If the CYA level is above 50 ppm you may want to do a partial drain/refill to lower it. Chlorine-shock your pool.

Step 3

Be sure to machine wash and dry all your swimwear. As an added precaution, use color-safe bleach in the wash cycle.  

Step 4

Clean all pool toys and floats with a chlorine-based cleanser (or 10 parts water to 1 part bleach).  

Step 5

Place all your submersible pool equipment in the shallowest part of your pool to make it easier to disinfect everything when you shock your pool for sanitizing.

Step 6

Brush any surfaces where algae have attached themselves with a strong algae brush. Continue brushing until all visible algae is free floating.

Step 7

Add algaecide to shock your pool.

Step 8

Vacuum or backwash your filter to make sure you’ve removed all dead algae.

Step 9

Get your WaterGuru SENSE to help keep your pool water in perfect balance.

Get algaecide products

Prevent more black algae

Step 1

Test and adjust pH and chlorine levels frequently. Because WaterGuru SENSE is calibrated precisely for your pool, you’ll always know exactly what to add and when.

Step 2

Brush pool surfaces weekly, so algae doesn’t have a chance to get a foothold.

Step 3

Maintain your Free Chlorine level relative to Cyanuric Acid (aka stabilizer) level. WaterGuru SENSE, TEST and pool chemistry advice in the WaterGuru app can help.

Pool smart. Delivers customized instructions on how to maintain your water in perfect balance with the least amount of chemicals.
SENSE’s proprietary film strip, made from glass components, stays submerged in water 24/7 without degrading, then exposes one-time-use chemistry pads for precise measurement.
SENSE samples the entire pool, not just the surface water. SENSE’s patented optical sensor precisely reads the color of each measurement pad, indiscernible to the naked eye.
Understand exactly what your pool needs. Mail in a sample of your pool’s water with TEST. We’ll send you back professional, lab-tested water quality data, calibrated precisely to your pool.

Never have to deal with algae again. Get WaterGuru SENSE.

Pool smart. Delivers customized instructions on how to maintain your water in perfect balance with the least amount of chemicals.
SENSE’s proprietary film strip, made from glass components, stays submerged in water 24/7 without degrading, then exposes one-time-use chemistry pads for precise measurement.
SENSE samples the entire pool, not just the surface water. SENSE’s patented optical sensor precisely reads the color of each measurement pad, indiscernible to the naked eye.
Understand exactly what your pool needs. Mail in a sample of your pool’s water with TEST. We’ll send you back professional, lab-tested water quality data, calibrated precisely to your pool.

Never have to deal with algae again. Get WaterGuru SENSE.