API POND ALGAEFIX Algae Control 16-Ounce Bottle (169B)
Original price was: $21.78.$15.41Current price is: $15.41.
Price: $21.78 - $15.41
(as of Oct 24, 2025 23:54:16 UTC – Details)
API POND ALGAEFIX Algae Control Solution 16-Ounce Bottle.
Is Discontinued By Manufacturer : No
Product Dimensions : 2 x 2 x 5 inches; 4.8 ounces
Item model number : 169B
Department : Unisex-Adult
Date First Available : July 7, 2007
Manufacturer : Mars Fishcare
ASIN : B000SP1WMC
Best Sellers Rank: #479 in Patio, Lawn & Garden (See Top 100 in Patio, Lawn & Garden) #1 in Water Garden & Pond Treatment
Customer Reviews: 4.3 4.3 out of 5 stars 21,698 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
100% dedicated to performance and clean environment
Product tested and safe for salt or fresh water setups
Cleaner ponds and tanks equal longer fish and aquatic life
Age Range Description: Senior
Customers say
Customers report that the pond treatment works quickly and effectively against string algae, keeping water clear. The product receives positive feedback for its quality, with one customer noting it’s recommended by a landscaper. While some customers find it a great value, others consider it not cost-effective. There are mixed experiences with fish survival, with some reporting no deaths while others experienced significant losses. The product’s safety for fish and wildlife is also debated, with some customers finding it safe while others warn it can be fatal to fish.
13 reviews for API POND ALGAEFIX Algae Control 16-Ounce Bottle (169B)
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Original price was: $21.78.$15.41Current price is: $15.41.
Craig G. –
Crystal Clear Koi Pond Again!
Went into August with crystal clear water in my koi pond… Until algae decided to take over. The water turned green and I couldn’t see any of my fish.I came across this product and gave it a shot. Took two doses, and my pond is almost back to crystal clear again.The directions are easy to follow.This product works!And the 21 fish I have in my pond are all doing fine.Highly recommend if you need to clear up your pond. Just make sure you read the directions! You need to keep the pond aerated while using it. I have 2 aerators and a waterfall.
Cassie B. –
The product works
I had purchased the smaller container of this product, and it works well, so I decided to buy the larger one since I’m experiencing a heavy bloom of algae in the South Florida sun and Heat. The product works. It can kill the algae, but much of it remains intact on the pond walls. You’ll need to brush it off the walls and then try to remove it from the bottom.
RandomCorkie –
MUST READ. It WILL NOT kill your fish IF……
LONG REVIEW, BUT PLEASE READ!!!Okay, so my pond is in 100% full sun so I have been dealing with warm, pea soup chlorella (planktonic) algae bloom all summer long. Not bad for the koi, but unsightly to the eye. All I wanted was to see the bottom of the pond and my koi through crystal clear water. Isn’t that what all of us koi pond owners want? Well, I finally caved and decided (per my brothers recommendation) to start looking into a non-copper algaecide. I am very familiar with APi products and trust the company, but after doing research and reading up on plenty of positive and negative reviews I was a bit leery in adding an unpredictable and unnecessary chemical to my pond, but I was so tired of the not seeing the true beauty of my koi and the green water didn’t smell great either. Please note that all water parameters are spot on: Ammonia 0, Nitrite 0, Nitrate 0, PH 8.2 (evening), KH 14 Drops. Pond is approximately 5000 gallons with a lot of filtration (won’t bore you with those details), including a UV filter, as well.Anyway, I called the company and left a voicemail for them to call me back because I had some questions regarding the negative reviews. They did return my call, but I missed it and I never called them back. I decided to purchase the product and dose carefully. A few things I know is that aeration plays an important part when using any algaecide. IT IS THE MOST IMPORTANT THING…..BUT…..Here is my experience with using this algaecide.So, my first treatment went very good, fish acted very normal and they didn’t seem to notice anything different. I (Please note; I added each treatment along with a natural cleaning bacteria to help break down decaying algae) By day two I noticed a slight clarity in the water. It was definitely working. I did a 10% water change at the end of day two. I waited the recommended three days before doing a second treatment. My second dose went just as well. No issues and koi were just fine. By the end of my second treatment, I could see three feet down! That’s 6 days after the first treatment and water was much more clear. It was working! Now, on day 6 before my third treatment I did a 20% water change to help remove the dead chlorella in the water column and did that using my go-to dechlorinator Sodium Thiosulfate. My intention was to add my third and final dose the next day but I forgot and I added the algaecide right after the water change. As soon as I added it I knew it was a BIG MISTAKE not to have waited at least 24 hours after the water change! DO NOT MIX THIS PRODUCT WITH ANY OTHER CHEMICALS WITHIN AT LEAST 24 HOURS OF USING THIS PRODUCT! All of my koi almost instantly disappeared to the bottom of the pond and some were seen darting around. I though I just killed my beloved koi and there wasn’t much I could do about it. Doing another water change with the necessary dechlor would probably do more harm than good so I added 10 lbs of charcoal to the waterfall. I didn’t see my koi at all the rest of the day. I thought for sure I would wake up to 27 dead koi in the morning. However, I woke in the morning to find all my koi swimming happily around looking for their breakfast.So my suggestions: AERATE AERATE AERATE (simple waterfall isn’t enough aeration) and DO NOT use with ANY other chemicals, especially dechlorinators such as Sodium Thiosulfate. I HIGHLY recommend NOT doing water changes within AT LEAST 24 hours of using this product. That is what will be detrimental to your koi and other fish. If fish show signs of stress, increase aeration and add carbon to remove the chemical agaecide.So, in conclusion, here are the pros and cons of this product:PROS:~Is highly effective against chlorella algae blooms (pea soup syndrome, I call it) Knocks back Chlorella blooms withing a day or two~Works fast~Easy to dose~Cost effectiveCONS:~Will harm your fish if used within 24 hours of doing a water change with dechlor (should say on the bottle, but doesn’t). API should put that on the bottle. ALWAYS AERATE.~Does turn dead carpet/hair algae a very ugly black color after killing it. But that’s normal.Hope this helps!Took a LOT longer to see results in killing the little amount of spring algae I had in the pond, but that wasn’t my target.
Nanc –
Crystal clear water all year!!
Tried others none of them worked as well as this one did! We didnât have any mold or algae all summer, water was crystal clear. Will purchase this again and again! Recommend highly for water fountains.
janet smith –
Works well in my small pond with koi
This product works well in my small pond with koi. Very happy with results
Phil Foster –
Be Patient
It took a year to remove the Algae. The water is currently clear. I did add chlorine tablets to the water.
Peter J. Smit, Jr. –
Good Product
Great product/ Takes a little time.
Azwoodsgirl –
Worked well
It worked as it should after applying the next morning lots of algae was floating on waters surface,however it was to fine to net out. I ended up doing a 50% water change. It took most of it out. This process was repeated for the next three applications. The water did clear up and the fish all survived as did the water lilies.
Dawn –
Ordered on 10 January 2025. Delivered on 20 January 2025. Thank you.
Radhika leela –
excellent
Marie Delaroche –
This product works very well. Fish are very happy and I have a beautiful pond once again.
Very good –
It works but expensive for ponds
Pakariverman –
Amazing results on just two days. Two months of algae bloom due continuous rain and sunny weather. Never experienced this in with my pond before. Fishes could no longer be seen.Fantastic API Algaefix …My pond is restored to be crystal clear again.