A green pool is one of the most challenging problems pool owners face. But, with a little elbow grease and chemicals, you can defeat this challenge within two days. Along with shock, algaecide is the most effective way to clear up algae and prevent it from growing again.
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Our Top 7 Algaecides For Pools
There are several algaecides on the market, each with its own specifications. When looking at algaecides, you should decide if you want a rapid cure, a 3-month solution, and what minerals you want to introduce to your pool ( see below). These picks cover algaecides in all forms and for all pools and will help clear a green pool.
- Bioguard 60 (Our Top Pick)
- Clorox Green Algae Eliminator (Best for Budget)
- HTH Super Algae Guard 60 (Best for Salt Water Pools)
- In The Swim Super Algaecide (Best for Low Odor)
- Aqua Clear Pool Algaecide (Best for Budget)
- Algaedyn Silver (Best Silver Algaecide)
- SeaKlear 90 Day ( Best for Long Term)
Top 7 Algaecides For Pools Compared
| Image | Product | Features | Link |
|---|---|---|---|
Our Top Pick  |
| 9.7 | Check Price |
Best For Budget  |
| 9.5 | Check Price |
Best for Saltwater Pools  |
| 9.1 | Check Price |
Best For Low Odor  |
| 8.8 | Check Price |
Best For Budget  |
| 8.6 | Check Price |
Best For Long-Term  |
| 8.2 | Check Price |
Types of Algaecides for Pools
There are three types of algaecides:
- Quaternary (quats)
- Polymer (polyquats)
- Copper or Silver based
When it comes to selecting an algaecide, your best option is to choose a formula that is specifically designed for your pool.
Silver
Silver algaecides are metallic based and are both algaecide and algaestat, which means that it kills bacteria and algae and also prevent algae from growing again. It’s part of the metallic family and can cause staining if used too much. It’s highly effective at killing all forms of algae, including black algae.
- Long-lasting
- Strong
- Clings well to pool walls and surfaces
- Expensive
- Could stain
- Burn-up chlorine residue
Polyquats
Polyquats are carbon-based and do not stain or foam. They have a positive charge that attaches and smothers the algae after you brush the exposed negative surface of the algae. Polyquats are effective in eliminating all types of algae. They work extremely well against green algae and are a great first choice in attacking algae issues.
- Non-foaming
- Non-staining
- Safe for all pools
- Slower acting than other algaecides
Copper
Copper algaecides are especially effective on black and yellow algae and are more powerful than quats and polyquats. They contain copper ions, which have been used for centuries in water treatment. The copper is bonded with amino acids to help prevent staining and efficiently kills all types of algae.
- Kills the toughest forms of algae
- Long-lasting
- Could stain
- Expensive
Quats
Quats kill algae by disrupting their cellular membranes. Quats effectively prevent algae, but they are a detergent, so adding too much causes excess odor, foaming, and staining.
- Less expensive than other algaecides
- Does not add metal to water
- Can foam, especially if the water is agitated
- Can have a chemical smell if overused
Which Type of Algaecide Should You Use?
| Type | Best For | Cost | Effectiveness |
| Quats | Green algae | Low | Effective for preventing algae |
| Polyquats | All types of algae | Expensive | Twice as effective as quats |
| Metallic/Copper | All types of algae | Medium | Effective on chlorine-resistant algae |
| Silver | Black and yellow algae | Expensive | Effective on chlorine resistant algae |
As the chart shows, they’re are different price points for algaecides and different levels of effectiveness. Quats are better suited for algae prevention, poly quats are twice as effective, and metallic and silver algaecides are best for large blooms or for hard-to-kill algae.
If you have a minor outbreak of green algae, I would start with a pol quat. If you use a metallic-based algaecide, follow the dosing instructions in the letter. When metallic-based algaecides are overused, they fall out of the water and will stain your pool walls, which will be noticeable by blue staining.
Copper vs. Regular Algaecide
Copper is much more efficient than regular algaecide unless you have a mineral purifying system. If you have such a system or a high level of copper in your water, you don’t want to add more metal to it. Regular algaecide is effective at preventing algae or if you have a small outbreak.
Polyquat vs. Copper vs. Silver
Polyquats are carbon-based instead of copper and work slower than copper and silver algaecides. Copper algaecides are the most popular and come in either crystal or liquid form. Silver-based algaecides come in liquid form and are the best for attacking yellow algae.
Algaecide 50 vs. 60: What’s the Difference?
Quats are known as algaecide 50 and have a strength of 50%. Polyquats have a strength of 60% algaecide and are highly effective at killing and preventing algae blooms. The more powerful polyquats work slower but are more effective, especially for recurring algae blooms.
I would use quats for smaller issues and polyquats for yellow or black algae.
What Do You Look For In The Best Algaecides For Pools?
Here are things you should consider when choosing an algaecide:
- Effectiveness
- Metallic or non-metallic-based
- Long-lasting treatment
- Algaecide plus algaestat
- Price
When looking for algaecides, you first need to determine the type and severity of the algae. And, if you’re considering a metallic algaecide, you need to know the mineral level of the water, especially the copper level. The price point is always important, but if you save a little on algaecide and the algae bloom reoccurs, the problem is more expensive as you’ll need to repeat the process.
That is not to say that a cheaper algaecide is less effective than an expensive one. What matters most is the algaecide percentage and what types of algae it treats. If you have a chlorine-resistant algae like black or yellow, you are going to need a stronger algaecide.
Best Algaecide For Pools Reviewed
1. Our Top Pick: Bioguard 60
- Works in chlorinated or brominated swimming pools
- Will not affect pH
- Non-foaming
Bioguard 60 is consistently at the top of our algaecide list and for good reason. It is a fast-acting algaecide that is effective for all types of algae at a decent price point. It carries minimal odor and is nonfoaming and nonstaining as well. Bioguard 60 is safe to use in bromine or chlorinated pools, attacks algae, and prevents future blooms. It’s copper-free, essential for mineral-generated pools or pools with high levels of metal in the water.
- Super effective
- Reasonably priced
- Good for all algae types
- Not recommended for saltwater pools
2. Best for Budget: Clorox Green Algae Eliminator
- Non-foaming formula
- Effective kill and preventative treatment
- Suitable for all pools
Clorox Green Algae Eliminator is a household name for cleaners, and they have branched out into swimming pool maintenance. Along with making decent chlorine tablets, the algae treatment is good for weekly maintenance to prevent algae buildup and will also eliminate green algae from your pool. It’s non-foaming and non-staining and works relatively well. Clorox has a handy app where you can keep track of your maintenance schedule and set reminders for when you need to restock pool supplies.
- Inexpensive
- Great for weekly use
- Non-foaming
- Only works for green algae
- Strong chemical smell
3. Best for Saltwater Pools: HTH Super Algae Guard 60
- 4-in-1 formula
- Kills and controls green, black, and yellow algae growth
- Non-foaming
HTH Super Algae Guard 60 is a preferred brand among professionals, It is a 60% algaecide that attacks the hardest-to-kill algae like yellow and black and is also effective against the more common green algae. It is also safe for all pool types, including above-ground pools. Even though it’s in the mid-price range, it is worth using as part of your weekly maintenance routine. It’s labeled as non-foaming, but many complaints have been that it does foam up when used.
- Low odor
- Preventative
- Fair price
- Foamy
4. Best for Low Odor: In The Swim Super Algaecide
- Great for spring openings and routine maintenance
- Copper-based
- Does not contain harmful chemicals
In The Swim Super Algaecide is a popular swimming pool chemical provider with a trusted name. Their algaecide is copper-based and is safe for all pool types. The concentrated formula is strong enough that it only takes 4 oz. per 10,000 gallons of water. At the price range and low dosage, this can definitely be used as a weekly or bi-weekly maintenance against algae formation. It’s strong enough to be potent against stubborn yellow algae and will prevent it from reforming.
- Strong (23.5% copper)
- Non-foaming
- No odor
- Can cause staining if overused
5. Best for Budget: Aqua Clear Pool Algaecide
- Fast-acting algae treatment
- For use with all pool types
- Salt water compatible
Aqua Clear Pool Algaecide is non-metallic and is effective at attacking green algae using ammonium compounds. It is safe for all pool types and chlorinating systems. This algaecide is popular with pool owners who have a mineral system because it is copper-free. It’s fast-acting and sells below $20, so it is also a decent weekly treatment for preventative maintenance.
- Inexpensive
- Can be used as a green algae preventative
- Foams
- Only treats green algae
6. Best Silver Algaecide: Algaedyn Silver
Algaedyn Silver is the most effective black algae remover because of its concentrated strength. It is also an algaestat and prevents algae growth for weeks after use. If you have reoccurring or chlorine-resistant algae, this is the algaecide for you. It also cleans the pool’s plumbing system and filter, which is necessary when killing concentrated algae like black algae and pink slime.
- Improves the effectiveness of your chlorine
- One of the strongest algaecides on the market
- Rapid working
- Expensive
- Can cause staining if overused
7. Best for Long-Term: SeaKlear 90-Day
- Non-foaming
- Non-staining
- Effective against blue-green, black, and mustard algae
SeaKlear 90-Day only requires application every 90 days, which is impressive. It is good for all algae types and has a non-staining formula. It takes 16 oz. per 10,000 gallons for normal algae treatments and 32 oz. for severe algae, which is a high dosage but broad spectrum and leaves a long-lasting residual effect in your pool water. It can be used in all pool types and works in less than 24 hours.
- Long-lasting
- Strong, residual formula
- Nonfoaming
- Non-staining
- High dosage
- Copper-based (a con for mineral systems)
Should You Use Algaecide or Chlorine Shock?
Chlorine shock is usually the best way to kill algae in a swimming pool. But if you’re fighting chlorine-resistant algae like the black or yellow variants, algaecide is necessary. Even if you use algaecide, you will still need to use chlorine shock.
Algaecides shine in that most of them prevent algae from forming, and a small dosage can be used weekly or even biweekly. It’s also a good idea to use algaecide when you shut your pool down for the winter or open it for the spring.
