The 8 Best Algaecides
We spent 21 hours on research, videography, and editing, to review the top choices for this wiki. It's hard to enjoy a pool or hot tub or to stand back and admire your pond or fountain when the water is green and slimy with algae. Fortunately, we have assembled a list packed with products designed to combat various strains of these unwanted little organisms in all of those diverse aquatic settings. When users buy our independently chosen editorial picks, we may earn commissions to support our work. Skip to the best algaecide on Amazon.
8. PondCare Algaefix
A quart of this PondCare Algaefix solution can all but eradicate even the toughest algae blooms in ponds and fountains filled with up to 9,600 gallons of water. Not only will the formula not hurt fish and other wildlife, but it will help them by providing cleaner water.
- breaks up blanketweed growth
- ideal for regular maintenance
- kills some wanted plants as well
|Rating||3.7 / 5.0|
7. In The Swim Super Pool
In The Swim Super Pool is a super-fast-acting formula thanks to its 23.5% concentration of copper triethanolamine complex. It is especially effective at killing off and preventing the return of mustard algae, one of the more recalcitrant varieties.
- 1 ounce treats 5000 gallons
- safe for people of all ages
- cannot be sold in several states
|Brand||In The Swim|
|Rating||3.6 / 5.0|
6. SeaKlear 90-Day
If you love having an algae-free swimming pool but you hate regular pool maintenance, then try using SeaKlear 90-Day Prevention & Remover. When used in water that is properly treated with bromine, chlorine, or ozone, it prevents algae growth for months at a time.
- kills black and yellow algae
- backed by satisfaction guarantee
- helps prevent but poor for treatment
|Rating||3.8 / 5.0|
5. GLB Pool & Spa Products
A single quart-sized bottle of GLB Pool & Spa Products Strike Out formula will quickly eradicate both green and mustard algae, and prevents these pesky organisms from returning well after treatment. It is strong but safe, leaving a pool immediately ready for enjoyment.
- works in chlorine or bromine pools
- breaks up thick layers of algae
- may cause staining
|Brand||GLB Pool & Spa Products|
|Rating||4.4 / 5.0|
4. GreenClean Granular
A bucket of GreenClean Granular belongs in the garage or shed of everyone who owns or maintains a pond or fountain that fish call home. The formula is safe for almost all aquatic and avian animals and for any mammals who may drink from your water feature.
- starts clarifying water in minutes
- copper- and phosphate-free
- one bucket treats 16000 gallons
|Rating||3.9 / 5.0|
3. EasyCare 50064 FounTec
EasyCare 50064 FounTec was specifically designed for one of the most algae-prone fixtures of any home or business: the fountains. This maximum-strength formula kills off photosynthetic organisms and cleans and clarifies water with just one drop per gallon.
- removes need for chlorine
- environmentally safe
- harmful to fish
|Brand||EasyCare 50064 FounTec|
|Rating||4.5 / 5.0|
2. Clorox Pool & Spa 41128CLX
If you have some serious algae buildup issues in your pool, consider getting a gallon-sized container of Clorox Pool & Spa 41128CLX Green Algae Control formula. One bottle should be able to treat even a 25,000 gallon pool several times.
- safe for all pool interiors
- inexpensive for large quantity
- trusted brand name
|Rating||4.7 / 5.0|
1. Kem-Tek Pool and Spa
One bottle of Kem-Tek Pool and Spa goes a long way thanks to its 60% concentration of active chemical ingredients. It is safe for use with all standard pool and hot tub filtration systems, and serves equally well to prevent and treat growth.
- non-foaming formula
- quickly clarifies water
- trusted by pool care professionals
|Rating||4.6 / 5.0|