

🧪 Transform your tank with nature’s own cleaning crew!
API STRESS ZYME is a 16-ounce liquid aquarium cleaning solution containing over 300 million live bacteria per teaspoon. Designed for both freshwater and saltwater tanks, it naturally consumes sludge, fish waste, and organic debris to reduce maintenance and promote a healthy, balanced aquatic environment. Trusted by aquarists for nearly six decades, this product supports a strong biological filter and keeps gravel, decorations, and glass clean with weekly use.













| ASIN | B000255N3W |
| ASIN | B000255N3W |
| Allergen Information | Apple Free |
| Best Sellers Rank | #4,025 in Pet Supplies ( See Top 100 in Pet Supplies ) #19 in Aquarium Water Treatments |
| Brand Name | API |
| Customer Reviews | 4.8 4.8 out of 5 stars (12,075) |
| Date First Available | June 20, 2004 |
| Department | Unisex-Adult |
| Global Trade Identification Number | 00317163160565 |
| Is Discontinued By Manufacturer | Yes |
| Item Form | Liquid |
| Item Type Name | Aquarium Sludge Remover |
| Item Weight | 544.31 Grams |
| Item model number | 56E |
| Liquid Volume | 473 Milliliters |
| Manufacturer | Mars Fishcare |
| Manufacturer | Mars Fishcare |
| Manufacturer Part Number | 56E |
| Model Number | 56E |
| Product Dimensions | 10 x 10 x 10 inches; 1.2 Pounds |
| Target Species | Fish |
| UPC | 317163160565 |
| Unit Count | 1 Count |
K**R
Great product
Works great! Simple directions and great value for the price.
S**R
10/10
Works really well with my tank keeping the water clear and helping reduce sludge on the filters which helps maintenance and keeping it running longer
M**S
Highly Recommend
Excellent Product..Thanks
A**6
Amazing product. Really works.
I use this weekly, RELIGIOUSLY. I do not miss a dose. This is my tank today, having not touched the filter in 18 months. (Fluval FX6 filled with only biohome filter media and polishing sponges.) I’ve only changed out the live plants when needed (pothos houseplant clippings) and used the magnetic algae glass scraper when needed. It’s a 75 gallon tank. I8 MONTHS!!! I highly recommend this product. Zero odor, zero nastiness.
H**I
The fish are doing well
I have been using this enzyme solution along with the API chlorine solution for about a year and seems to be working fine. The fish has survived :) It’s a little bit on pricy side.
G**O
Clear water
It works great. Keep my water crystal clear.
T**.
This really works
This really works! My plecostomoas was completely stressed out due to a faulty heater and was COMPLETELY pale in color. I started with a double dose and used it weekly and he is now over 75% back to normal color. Definitely recommend this for regular maintenance of your aquarium.
J**N
Great for my aquatic frogs
I use this religiously with my African dwarf frogs! They are still kicking strong after 3 years so it must be working!
K**A
It simply replaces all those starter kits as you can double the dose for a new aquarium to boost the biological filter. What a brilliant product! My guppies are happy with this.
S**M
Producto muy recomendable!el agua no se enturbia para nada,hay que tener un buen filtro,el mio no funciona bien y el agua no esta sucia pero huele mal por el filtrado,el producto es buenisimo.
S**A
I love the brand
D**S
I was having some issues controlling nitrites. Used it, two days later, down to zero and stable. I don't see any issues with my Ph, fish, snail, shrimp and plants. I'll keep dosing the water as instructed.
S**E
My regular go to solution after water change.. this has helped my ponds as well as big tanks for maintaining good bacterial colonies in sump and canister filters