---
product_id: 748223486
title: "API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals"
brand: "api"
price: "HK$483"
currency: HKD
in_stock: false
reviews_count: 5
url: https://www.desertcart.hk/products/748223486-api-stress-zyme-64-ounce-by-aquarium-pharmaceuticals
store_origin: HK
region: Hong Kong
---

# Treats up to 3840 gallons 64 oz powerful bio-filter booster Continuous organic waste breakdown API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals

**Brand:** api
**Price:** HK$483
**Availability:** ❌ Out of Stock

## Summary

> ♻️ Keep your tank thriving—because your fish deserve the best!

## Quick Answers

- **What is this?** API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals by api
- **How much does it cost?** HK$483 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.hk](https://www.desertcart.hk/products/748223486-api-stress-zyme-64-ounce-by-aquarium-pharmaceuticals)

## Best For

- api enthusiasts

## Why This Product

- Trusted api brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **No-Fridge Convenience:** Ready-to-use liquid formula that requires zero refrigeration
- • **Massive 64-Ounce Supply:** Long-lasting treatment covering up to 3840 gallons—perfect for serious hobbyists
- • **Organic Waste Breakdown:** Effectively neutralizes ammonia and nitrite, preventing toxic buildup
- • **Healthier Fish, Cleaner Water:** Continuous use guarantees optimal water quality and vibrant aquatic life
- • **Boost Your Aquarium’s Bio-Filter:** Enhances beneficial bacteria growth for a thriving aquatic ecosystem

## Overview

API Stress Zyme is a 64-ounce liquid aquarium treatment designed to boost biological filter development and break down harmful organic compounds like ammonia and nitrites. Treating up to 3840 gallons, it ensures cleaner water and healthier fish without the need for refrigeration, making it an essential solution for maintaining optimal aquarium conditions.

## Description

Improves the development of the biological filter and helps clean a dirty aquarium; Breaks down organic compounds that cause dangerous conditions such as as ammonia and nitrite poisoning and low oxygen levels; Continuous use assures an active biological filter, cleaner aquarium, healthier fish and good water quality; No refrigeration necessary; Treats 3840 gallons

Review: Good value for money
Review: Good

## Features

- API Stress Zyme, 64-Ounce
- 64 oz

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B000256DIQ |
| Batteries Included | No |
| Customer Reviews | 4.7 4.7 out of 5 stars (435) |
| Date First Available | August 3, 2012 |
| Is Discontinued By Manufacturer | No |
| Item Form | Liquid |
| Item model number | 56J |
| Volume | 828 |
| batteries required | No |

## Product Details

- **Brand:** API
- **Item Form:** Liquid
- **Item Weight:** 1.86 kg
- **Liquid Volume:** 64 Fluid Ounces
- **Manufacturer:** Aquarium Pharmaceuticals

## Images

![API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals - Image 1](https://m.media-amazon.com/images/I/311H6UG4nAL.jpg)
![API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals - Image 2](https://m.media-amazon.com/images/I/71XhhAyRlbL.jpg)
![API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals - Image 3](https://m.media-amazon.com/images/I/81DP-svsA7L.jpg)
![API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals - Image 4](https://m.media-amazon.com/images/I/81VdRQaYCRL.jpg)
![API Stress Zyme, 64-Ounce by Aquarium Pharmaceuticals - Image 5](https://m.media-amazon.com/images/I/91M80WNPvvL.jpg)

## Questions & Answers

**Q: Can I mix this with API Quick Start and API Stress Coat+ in a gallon every time I do water changes weekly? Or just pour it directly in my 5.5 tank?**
A: In short, you don't need the Stress Zyme if you already are using the Quick Start.  Here's a longer answer:The API Stress Coat is primarily a de-chlorinator and has aloe added to help maintain a healthy slime coat on the fish so this should always be added to the water and mixed before adding to the tank.  The API Quick Start is meant to jump start the biological cycling of a tank and is only needed for new tanks or potentially semi established tanks that have a spike in ammonia and nitrite levels which could be caused by adding more fish.  You can stop using this once your water chemistry has stabilized.  API Stress Zyme is very similar in function to the Quick Start and is generally chosen to improve water clarity or stabilize chemistry in more established tanks.    You don't need to use both simultaneously and would probably never see the difference compared to using just one.  On another note, I always add my bacteria after there is no chance there is any chlorine so they have a better chance of proliferating.  I would add either the Quick Start or the Stress Zyme the day after a water change, directly into the tank.

**Q: can i mix stress coat, stress zyme and tap water conditioner? if so what amount of each should i mix? doing this harm my fishes?**
A: Stress Coat and water conditioner is the same. ( stress Coat is water conditioner ). if you use both at the same time that you double it up. Maybe it is nothing will happening . But, it is not necessary to do that.

**Q: How long this product can be stored before it expires?  Also, would its effectiveness reduce during long time storage?**
A: As for length of time you can store, I use it weekly and it lasts for about four months or so. Does not seem to lose effectiveness in that time.

**Q: What is the expiration date on this Stress Zyme?  It seems very inexpensive.**
A: There is an expiration date on the bottle, however, these are live bacteria and once the bottle is open the shelf life is cut in half. Same as Seachems Pristine. Buy the size bottle for your tank. There is 250ml and 500 or 750ml, depending on the brand. My personal and professional advice is buy the smaller one 1st and see how much you go through, follow the instructions completely. They work well, keeps the glass cleaner longer. Also very important, make sure the aeriation is adequate and they say to change the filters 1st. If you have the $$ go for it. Best and least expensive and just as sufficient, is to change them half way before you normally change out your filters. API Stress zyme seems to keep its life span quite a while after opening. But trust me, you'll use it up way before it expires. Compared to the other similar products, this one seems to leave more of a brownish pile on the corners or underneath Ornaments, whis in turn will have to be vacuumed, netted or a baster for cooking depending on the size of your tank. 👍

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by N***N on November 2, 2025*

Good value for money

### ⭐⭐⭐⭐⭐ Review
*by G***V on September 18, 2025*

Good

### ⭐⭐⭐⭐⭐ Review
*by S***O on October 24, 2023*

Used this product for years. A bit disappointed I couldn't get it in a gallon size. But always on inventory in my house and use it when i do a water change in the aquariums at about half dose. Vital for new aquarium setups to get established!

## Frequently Bought Together

- API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution 64-Ounce Bottle
- API STRESS COAT Aquarium Water Conditioner 64-Ounce Bottle
- API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria 32-Ounce Bottle

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.hk/products/748223486-api-stress-zyme-64-ounce-by-aquarium-pharmaceuticals](https://www.desertcart.hk/products/748223486-api-stress-zyme-64-ounce-by-aquarium-pharmaceuticals)

---

*Product available on Desertcart Hong Kong*
*Store origin: HK*
*Last updated: 2026-02-09*