How to Get Rid of Pool Algae: Algae Complete® + Shock Treatment Guide
Pool algae can usually be eliminated by removing debris, balancing the pH, aggressively brushing the pool, shocking the water, adding an algaecide such as BioGuard Algae Complete®, and continuously filtering the water. For heavier algae blooms, especially when you cannot see the bottom of the pool, using a flocculant and vacuuming the debris directly to waste may make the cleanup process faster and reduce the amount of algae being captured by the filter.
This guide explains how Premier Pool & Spa recommends treating green pool algae using BioGuard Algae Complete® and pool shock, including chemical amounts for pools from 10,000 to 40,000 gallons.
Premier Pool & Spa Service Department
Minnesota Pool Service & Maintenance
Last updated: September 2026
Quick Answer: How Do You Treat Algae in a Swimming Pool?
For most algae blooms, follow these steps:
- Make sure the pump and filtration system are working properly.
- Adjust the pool pH to 7.2–7.6.
- Vacuum leaves, algae clumps, and other debris from the pool.
- Aggressively brush the pool walls, floor, steps, corners, ladders, and fittings.
- Add a double dose of oxidizer. Premier Pool & Spa recommends 2 lbs of BioGuard Super Soluble per 10,000 gallons.
- Circulate the water for 1 hour.
- Add 16 fluid ounces of BioGuard Algae Complete per 10,000 gallons.
- Run the pump and filter continuously for 24 hours with the pool cover open or off.
- After 24 hours, evaluate the chlorine level, water clarity, and remaining algae before adding additional chemicals.
Should You Use This Algae Treatment or a Flocculant First?
Use this Algae Complete + shock treatment if:
- You have a light algae bloom.
- You have a heavier algae bloom but cannot vacuum the pool directly to waste.
- The pool is green or cloudy but does not contain a large amount of settled organic debris.
If you cannot see the bottom of the pool and you are able to vacuum directly to waste, we generally recommend using a flocculant first.
A flocculant helps suspended algae, dirt, and organic material settle to the bottom of the pool so it can be physically removed instead of being sent through the filtration system.
Vacuuming to waste means removing dirty pool water and debris directly from the pool without sending it through the filter. A robotic pool cleaner does not vacuum to waste.
Not sure how to do this? See our step-by-step guide to manually vacuuming a pool and vacuuming to waste.
If algae remains after the flocculant treatment, use the Algae Complete and shock treatment described below.
For detailed flocculant instructions, see our guide to using Revive!® to clean algae and contaminants from a pool.
If you would prefer professional help clearing the pool, contact the Premier Pool & Spa Service Department and ask about our Green to Clean Service. Availability may be limited during the spring season.
Pool Algae Treatment at a Glance
| Step | What to Do |
| 1 | Confirm the pump and filtration system are operating properly. |
| 2 | Adjust pH to 7.2–7.6. |
| 3 | Vacuum leaves and visible debris before brushing. |
| 4 | Brush all pool surfaces aggressively. |
| 5 | Add 2 lbs of Super Soluble per 10,000 gallons. |
| 6 | Circulate for 1 hour. |
| 7 | Add 16 oz of Algae Complete per 10,000 gallons. |
| 8 | Run the pump continuously for 24 hours with the cover open. |
Step 1: What Should You Check Before Treating Pool Algae?
Before adding chemicals, make sure the pool's circulation and filtration system are working properly.
Check that:
- The pool pump is operating.
- Water is circulating properly through the pool.
- Cartridge filters are clean enough to maintain proper flow.
- Sand filters are backwashed if needed.
- DE filters are cleaned or backwashed as needed.
Proper circulation and filtration are extremely important during algae cleanup. Chemicals can kill algae, but the filtration system still needs to remove the dead algae and suspended debris from the water.
Filter help: If you have a cartridge filter, see How to Clean Cartridge Filters on Your Pool. If you have a sand or DE filter, see How to Backwash Your Pool Filter.
Step 2: What pH Should a Pool Be Before Treating Algae?
Before beginning the algae treatment, test and adjust the pool's pH to 7.2–7.6.
Maintaining the correct pH helps the chlorine, oxidizer, and algaecide work effectively.
Step 3: Should You Vacuum or Brush the Pool First?
Vacuum the pool before brushing whenever possible.
Remove leaves, large algae clumps, dirt, and other visible debris first. Chlorine and algaecide react with organic material in the pool. Removing the largest particles allows the treatment chemicals to focus on the smaller algae particles remaining in the water.
Brushing first can stir algae and debris into the water, making it harder to see where you are vacuuming.
For detailed instructions, see our complete guide to manually vacuuming your pool and vacuuming to waste.
Step 4: How Should You Brush a Pool With Algae?
Aggressively brush all pool surfaces, including:
- Pool walls
- Pool floor
- Steps
- Corners
- Behind ladders
- Around return fittings
- Areas with visible algae growth
Brushing helps break apart the algae's protective layer and exposes more of the algae to chlorine and algaecide.
Step 5: How Much Shock and Algae Complete Should You Add?
Apply an oxidizer according to the product label. For this treatment method, Premier Pool & Spa recommends BioGuard Super Soluble at a double dose of 2 lbs per 10,000 gallons of pool water.
Unlike liquid chlorine, Super Soluble will remain in the pool water and continue working against the algae for a longer period of time.
How to Apply the Chemicals
- Add the recommended oxidizer or shock.
- Allow the water to circulate for 1 hour.
- With the pump and filter operating, add 16 fluid ounces of Algae Complete per 10,000 gallons of pool water.
- Apply Algae Complete directly to the pool water, concentrating on areas with the heaviest algae growth.
- Run the pool pump and filtration system continuously for 24 hours.
- Leave the pool cover open or off during treatment.
Pool Algae Chemical Dosage Chart
The following chart shows the treatment amounts used in this algae cleanup method.
| Pool Size | Super Soluble or Smart Shock | 12.5% Liquid Chlorine (Not Recommended) |
Algae Complete |
| 10,000 gallons | 2 lbs | 4 gallons | 16 oz |
| 20,000 gallons | 4 lbs | 8 gallons | 32 oz |
| 30,000 gallons | 6 lbs | 12 gallons | 48 oz |
| 40,000 gallons | 8 lbs | 16 gallons | 64 oz |
What Should You Do After 24 Hours?
After the pool has circulated continuously for approximately 24 hours, evaluate three things:
- Is the water becoming clearer?
- Is the pool maintaining a chlorine reading?
- Is visible algae still present?
What If There Is Little or No Improvement?
If there is little or no improvement after treatment, consider using a flocculant to settle the algae and suspended debris to the bottom of the pool so it can be vacuumed out.
See our Revive!® pool cleanup guide for step-by-step instructions on settling contamination and vacuuming it to waste.
What If the Pool Is Improving and Still Holding Chlorine?
If the pool is visibly improving and maintaining a chlorine reading, brush and vacuum the pool again, but do not immediately add more chemicals.
If the pool is holding chlorine, much of the algae is likely dead. The remaining cloudiness may simply require additional circulation and filtration time.
What If the Chlorine Is Good but the Pool Is Still Cloudy?
If the chemical levels remain good for approximately 48 hours but the water is not clearing, there is likely a circulation or filtration problem that needs to be addressed.
At that point, troubleshoot the pool's:
- Filter condition
- Filter sizing
- Pump operation
- Water circulation
- Return flow
- Skimmer flow
If you have a sand filter, our Sand Filters: An Overview guide explains how sand filtration works, common causes of cloudy water, backwashing, and signs that the filter media may need attention.
Cartridge-filter owners can also review our cartridge filter cleaning guide.
What If the Pool Keeps Losing Chlorine?
If the pool is clearing but the chlorine level repeatedly drops back to zero, add another double dose of oxidizer.
Also make sure the pool has a continuous source of sanitizer, such as:
- Chlorine tablets
- A properly operating salt chlorine generator
The pool may be experiencing a chlorine demand.
Chlorine demand occurs when contaminants in the pool consume chlorine faster than the pool can maintain a measurable sanitizer residual.
If your pool uses a salt system and is not maintaining chlorine, see our guide to determining whether a pool salt cell is working or needs replacement.
When Is It Safe to Swim After Treating Pool Algae?
Before entering the pool, test the chlorine level.
Do not enter the pool until the chlorine level has returned to 1–5 ppm.
The water should also be clear enough that the bottom of the pool is visible.
What About Mustard Algae or Black Algae?
Mustard algae and black algae are very rare in vinyl-liner swimming pools in Minnesota.
In Premier Pool & Spa's experience servicing residential pools in Minnesota, most green pools are dealing with standard green algae rather than true mustard or black algae.
If mustard or black algae is present, the general treatment process is similar, but these algae types are more difficult to eliminate. Chlorine may need to be maintained at a substantially higher level for a longer period of time.
Pool brushes, vacuum equipment, cleaning tools, and other items that have been exposed to mustard or black algae may also need to be placed in the pool during treatment so algae remaining on those surfaces is killed and is not reintroduced into the pool.
Important Pool Algae Treatment Tips
- 🚫 Do not swim until chlorine has returned to a safe level.
- ✅ Run the pool pump continuously during cleanup whenever possible.
- ✅ Clean or backwash the filter as needed during algae cleanup.
- ✅ Vacuum debris before brushing whenever possible.
- ✅ Leave the pool cover open during treatment.
- ✅ Continue brushing and filtering after the algae has died until the water is completely clear.
How Do You Prevent Pool Algae From Coming Back?
Once the pool is clear:
- Maintain proper chlorine levels.
- Brush the pool weekly.
- Use Algae Complete® weekly at 1.5 oz per 10,000 gallons.
- Maintain consistent filtration and circulation.
- Keep the filter clean and operating properly.
If algae repeatedly returns despite maintaining proper pool chemistry, there is likely a problem with the pool's circulation or filtration system.
Contact Premier Pool & Spa if you need help troubleshooting a filtration or circulation problem.
Frequently Asked Questions About Pool Algae
Can You Add Algae Complete and Shock to the Pool on the Same Day?
Yes. In this treatment method, add the oxidizer first, allow the pool to circulate for approximately 1 hour, and then add Algae Complete while the pump and filter are operating.
How Much Shock Do You Need for a Green Pool?
For the treatment described in this guide, Premier Pool & Spa recommends a double dose of BioGuard Super Soluble at 2 lbs per 10,000 gallons of pool water.
How Much Algae Complete Do You Use for a Green Pool?
For an active algae treatment, use 16 fluid ounces of Algae Complete per 10,000 gallons of pool water as described in this guide. This equals 32 oz for 20,000 gallons, 48 oz for 30,000 gallons, and 64 oz for 40,000 gallons.
Should You Brush or Vacuum a Green Pool First?
Vacuum first whenever possible. Brushing can stir algae and debris into the water and make it more difficult to see where you are vacuuming. See our manual pool vacuuming guide for instructions.
Should You Run the Pool Pump Overnight When Treating Algae?
Yes. During algae treatment, continuously circulate and filter the pool water for approximately 24 hours whenever possible.
Why Is My Pool Still Cloudy After the Algae Is Dead?
Dead algae and fine suspended debris still need to be removed by the filtration system. If the pool is holding chlorine and continuing to improve, additional filtration time may be all that is needed.
Why Is My Pool Still Cloudy After 48 Hours?
If chlorine and other chemical levels remain good but the pool is not clearing after approximately 48 hours, investigate the filtration and circulation system. Depending on your filter type, see our guides for cleaning cartridge filters, backwashing sand and DE filters, or troubleshooting sand filters.
Why Does My Pool Keep Losing Chlorine?
The pool may have a high chlorine demand caused by algae, organic debris, or other contaminants consuming chlorine faster than a measurable residual can be maintained. If the pool uses a salt chlorine generator, confirm that the salt cell is producing chlorine properly. Our salt-cell troubleshooting guide can help with that process.
Can I Use a Robotic Pool Cleaner Instead of Vacuuming to Waste?
No. A robotic cleaner collects debris internally and does not remove dirty pool water directly from the pool. Vacuuming to waste sends the debris and contaminated water out of the pool without passing it through the filtration system. See How to Manually Vacuum Your Pool & Vacuum to Waste for instructions.
Should You Use Flocculant on a Green Pool?
A flocculant can be especially useful when the pool is so cloudy or green that you cannot see the bottom and you have the ability to vacuum the settled material directly to waste. See our guide to using Revive!® for pool cleanup for more information.
When Is It Safe to Swim After Treating Pool Algae?
Do not swim until the chlorine level has returned to 1–5 ppm and the pool water is clear enough to safely see the bottom.
Professional Green Pool Cleanup in Minnesota
If you prefer to have a professional clear the pool, contact the Premier Pool & Spa Service Department and ask about our Green to Clean Service.
Premier Pool & Spa services residential swimming pools throughout our Minnesota pool service area. Green to Clean availability may be limited during the busy spring season.
Related Pool Maintenance Guides
- How to Manually Vacuum Your Pool & Vacuum to Waste – Learn how to remove debris directly from the pool instead of sending it through the filter.
- How to Use Revive!® to Clean Your Pool – Step-by-step instructions for settling algae and contaminants before vacuuming them to waste.
- How to Clean Cartridge Filters on Your Pool – Improve circulation and filtration when cartridge filters become dirty.
- How to Backwash Your Pool Filter – Instructions for properly backwashing sand and DE pool filters.
- Sand Filters: An Overview – Learn how sand filtration works and troubleshoot common filtration and cloudy-water problems.
- How to Tell if Your Pool Salt Cell Is Working – Troubleshoot low chlorine when using a salt chlorine generator.
