---
product_id: 343992831
title: "API PH Down Aquarium PH Adjuster, 16-Ounce"
brand: "api"
price: "23.28 OMR"
currency: OMR
in_stock: true
reviews_count: 5
category: "Api"
url: https://www.desertcart.com.om/products/343992831-api-ph-down-aquarium-ph-adjuster-16-ounce
store_origin: OM
region: Oman
---

# Safe for fish & plants 16 fl oz precision dosing pH lowering control API PH Down Aquarium PH Adjuster, 16-Ounce

**Brand:** api
**Price:** 23.28 OMR
**Availability:** ✅ In Stock

## Summary

> 🐠 Keep your aquatic world balanced and thriving with API pH Down!

## Quick Answers

- **What is this?** API PH Down Aquarium PH Adjuster, 16-Ounce by api
- **How much does it cost?** 23.28 OMR with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.om](https://www.desertcart.com.om/products/343992831-api-ph-down-aquarium-ph-adjuster-16-ounce)

## 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

- • **Versatile Use Case:** Ideal for new setups, routine pH balancing, and water changes to maintain stability.
- • **Compact & Convenient:** 16-ounce liquid bottle designed for easy handling and accurate dosing.
- • **Precision pH Control:** Easily adjust freshwater aquarium pH to optimal levels for diverse species.
- • **Trusted Brand Legacy:** Over 50 years of API innovation ensures reliable, research-backed aquarium care.
- • **Fish & Plant Safe Formula:** Gentle yet effective solution that protects your aquatic ecosystem’s health.

## Overview

API PH Down is a 16-ounce liquid solution designed to safely lower pH levels in freshwater aquariums. Trusted for over 50 years, it supports a healthy environment for tropical fish and plants by maintaining ideal acidity levels, ensuring your aquatic community thrives with minimal effort.

## Description

pH is the measure of acidity of water, on a scale ranging from 0 to 14. A pH of 0 is the most acidic, while a pH of 14 is the most alkaline. Different geographies have different tap water conditions with different pH levels, while fish require a specific pH level to thrive. A pH of 7.0 is ideal when keeping a community aquarium containing a variety of tropical fish. Goldfish and livebearers prefer a pH of 7.5. Many desertcartian fish, like angelfish and neon tetras, prefer a pH of 6.5 to 6.8. Mollies and swordtails thrive at pH 7.2 to 7.5. API pH DOWN Freshwater Aquarium Water pH Reducing Solution lowers aquarium pH in freshwater aquariums to desired level. Safe for fish and plants. Use when setting up a new aquarium, adjusting pH, or changing water. pH in an aquarium can fluctuate due to fish waste, uneaten food and addition of tap water. It is recommended to test water for pH weekly. With API Aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your fish and aquarium. API Aquarium Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your tank. Make sure to use all products as directed in order to ensure the best results.

Review: Works good follow instructions.
Review: Easy directions and it works.

## Features

- For freshwater aquariums
- Lowers pH levels
- Safe for fish and plants

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0002ASGBS |
| Brand | API |
| Country of Origin | USA |
| Global Trade Identification Number | 00017163020301 |
| Item Dimensions LxWxH | 6.4 x 6.4 x 22.2 Centimeters |
| Item Form | Liquid |
| Item Weight | 544 g |
| Item model number | 30B |
| Liquid Volume | 16 Fluid Ounces |
| Manufacturer | Aquarium Pharmaceuticals |
| Product Dimensions | 6.35 x 6.35 x 22.23 cm; 544.31 g |
| UPC | 017163020301 |

## Product Details

- **Brand:** API
- **Item Form:** Liquid
- **Item Weight:** 544 g
- **Liquid Volume:** 16 Fluid Ounces
- **Manufacturer:** Aquarium Pharmaceuticals

## Images

![API PH Down Aquarium PH Adjuster, 16-Ounce - Image 1](https://m.media-amazon.com/images/I/51btxDh9MZL.jpg)
![API PH Down Aquarium PH Adjuster, 16-Ounce - Image 2](https://m.media-amazon.com/images/I/81vGj7jp3yL.jpg)
![API PH Down Aquarium PH Adjuster, 16-Ounce - Image 3](https://m.media-amazon.com/images/I/91PmUNmU56L.jpg)
![API PH Down Aquarium PH Adjuster, 16-Ounce - Image 4](https://m.media-amazon.com/images/I/81arn3qWjLL.jpg)
![API PH Down Aquarium PH Adjuster, 16-Ounce - Image 5](https://m.media-amazon.com/images/I/91b7ZeUL4VL.jpg)

## Questions & Answers

**Q: Lowered my ph from 8 to 7.6 and now it is stuck regardless of how much I put in.  I have driftwood and all levels are normal.  What to do?**
A: We would recommend to continue to use API pH Down everyday until you achieve the pH you are looking for. However, if it will not lower we would recommend to have the KH tested. This could be preventing the pH from moving.

**Q: I haven’t had a fish tank in years so I am kinda new again but if my ph is 7.3 do I add ph up or ph down**
A: Depends on what kind of fish you have and what pH is suitable for that.

Having said that, 7.2-7.4 is most common so I would just leave it at 7.3 unless your fish over other requirements.

**Q: Will this reduce alkalinity (KH)? Will this work for low KH water?**
A: No, this will not reduce the KH of the water.

**Q: Is it safe to use on Saltwater aquarium?**
A: API pH Down is safe to use in a saltwater aquarium.  Most saltwater aquariums do not have a concern with high pH so what is the root cause.  Your saltwater mix should set the pH appropriately and overtime the aquarium biological conditions will drop the pH.  I would certainly check your salt mix and then look at what a additives you are adding to drive the pH up.

## Customer Reviews

### ⭐⭐⭐⭐ Review
*by B***R on 2 April 2023*

Works good follow instructions.

### ⭐⭐⭐⭐⭐ Review
*by J***O on 3 November 2020*

Easy directions and it works.

### ⭐⭐⭐⭐⭐ Review
*by W***N on 2 July 2025*

Easy to order, received without issues in good condition and does wonders for fish tank.

## Frequently Bought Together

- API Aquarium Pharmaceuticals 30B pH Down Aquarium pH Adjuster, 16 oz, Model Number: 17163020301, Hook
- API Marine Bundle Pack: One (1) API SALTWATER MASTER TEST KIT, one (1) API MARINE FLAKES Fish Food
- API AMMONIA 130-Test Freshwater and Saltwater Aquarium Water Test Kit

---

## 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.com.om/products/343992831-api-ph-down-aquarium-ph-adjuster-16-ounce](https://www.desertcart.com.om/products/343992831-api-ph-down-aquarium-ph-adjuster-16-ounce)

---

*Product available on Desertcart Oman*
*Store origin: OM*
*Last updated: 2026-02-21*