Updated date:

How to Use Floccing Agent to Clean a Green and Cloudy Pool

Rob is a pool-service industry professional with over 20 years of experience.

First arrived at pool

I recently received a service call for a green pool cleaning. The state of the pool when I first arrived is pictured above. Below is a step-by-step explanation of how to turn your pool from green to blue.

1. Test the pH

When I tested the water, the P.H. was around 7.2. That is a little low for pool water, but perfect for adding shock.

2. Add Granular Chlorine or "Shock"

Because this particular pool was a bit larger than most residential pools, I added approximately seven pounds of granular chlorine, also known as calcium hypo-chloride or shock. Within five minutes, the water began to lose its green coloring and began to turn blue again.

Five minutes after adding shock.

Five minutes after adding shock.

3. Add Floccing Agent

Flocculation is a process in which a chemical, or floccing agent, is added to green pool water. The solution causes algae particles to bind together and sink to the bottom of the pool. After the particles sink, they can be vacuumed.

4. Clean the Filter

The next step is to make sure the filter is clean, since the pump will need to run for 24 hours. With a D.E. filter, you will need to backwash.

Shut off timer is set and valve is positioned for backwash.

Shut off timer is set and valve is positioned for backwash.

5. Let the Pump Run

Green water being backwashed.

Green water being backwashed.

6. Add Four Scoops of D.E. Powder

Add four scoops of D.E. powder to coat the filter grids. This is added directly through the skimmer while the pump is running.

Adding D.E. powder through the skimmer.

Adding D.E. powder through the skimmer.

7. Set the Timer

Now the timer needs to be set to run continuously until the next day. Remove the "off" trip lever to allow the pump to run until it is manually shut off.

Removing the "off" trip lever

Removing the "off" trip lever

8. Vacuum the Remaining Residue

After being subjected to treatment for 24 hours, the pool should have become clear. There may some stubborn areas, especially on the walls. On the bottom of the pool, there may be dead algae and some leftover shock dust. This needs to be vacuumed. You can only vacuum these particles if a D.E. filter is being used, otherwise it needs to be vacuumed to waste.

The pool 24 hours into the treatment process.

The pool 24 hours into the treatment process.

9. Backwash the Filter

After the pool has been vacuumed, backwash the filter again.

10. Scrub Remaining Residue With a Brush

You should brush the green areas that can't be reached by the vacuum, such as the tiles, steps, etc.

11. Check for Chemical Balance.

Chemicals should be well balanced. The chlorine level may be slightly elevated.

Final result.

Final result.

12. Enjoy!

The finished result should be a clear, bright blue pool.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: I was always told to add shock to the pool before noon when the sun is shining. It’s overcast right now; can I still do the Green to Clean now?

Answer: Shock can be added at any time. Especially since you are treating a green pool. The hot sun can tend to burn off chlorine faster, but the green pool needs to be treated and the sooner, the better. The chlorine will remain high for a few days after shocking anyway whether or not the sun is out.


Sarah Carlsley from Minnesota on June 12, 2012:

Looks like you got it all figured out here when it comes to pools! Nice hub!

Related Articles