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.
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.
- Bioguard Algae All 60 (Our Top Pick)
- Clorox 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)
Best Algaecide For Pools Compared
Our Top Pick
Best For Budget
Best for Saltwater Pools
Best For Low Odor
Best For Budget
Best For Long-Term
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 algaecides are metallic-based and are both algaecide and algaestat, which kills bacteria and algae and prevents algae from growing again. It’s part of the metallic family and can cause too much staining. It’s highly effective at killing all forms of algae, including black algae.
- Clings well to pool walls and surfaces
- Could stain
- Burn-up chlorine residue
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.
- Safe for all pools
- Slower acting than other algaecides
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 is efficient in killing all types of algae.
- Kills the toughest forms of algae
- Could stain
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?
|Effective for preventing algae
|All types of algae
|Twice as effective as quats
|All types of algae
|Effective on chlorine-resistant algae
|Black and yellow algae
|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, polyquats 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:
- Metallic or non-metallic based
- Long-lasting treatment
- Algaecide plus algaestat
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 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
Bioguard 60 is consistently at the top of 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 non-foaming and non-staining as well. Bioguard 60 is safe to use in bromine or chlorinated pools, attacks algae, and prevents future blooms. It’s copper-free, and 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.
- Great for weekly use
- 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
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 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 exist that it does foam up when used.
- Low odor
- Fair price
4. Best for Low Odor: In The Swim Super Algaecide
- Great for spring openings and routine maintenance
- 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)
- 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 with 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.
- Can be used as a green algae preventative
- Only treats green algae
6. Algaedyn Silver
Algaedyn 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 a necessity 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
- Can cause staining if overused
7. Best for Long-Term: Seakleer 90 Day
- Effective against blue-green, black, and mustard algae
Seakleer 90 Day only requires an 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.
- Strong, residual formula
- 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 algaecide is necessary if you’re fighting chlorine-resistant algae like the black or yellow variants. 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 bi weekly. It’s also a good idea to use algaecide when you shut your pool down for the winter or open it for the spring.