---
product_id: 12774984
title: "API pH UP Freshwater Aquarium Water pH Raising Solution for fish,4-Ounce Bottle, Brown"
brand: "api"
price: "£6.42"
currency: GBP
in_stock: true
reviews_count: 13
category: "Api"
url: https://www.desertcart.co.uk/products/12774984-api-ph-up-freshwater-aquarium-water-ph-raising-solution-fish
store_origin: GB
region: United Kingdom
---

# Safe for fish & plants 4 fl oz precision dosing Phosphate-free formula API pH UP Freshwater Aquarium Water pH Raising Solution for fish,4-Ounce Bottle, Brown

**Brand:** api
**Price:** £6.42
**Availability:** ✅ In Stock

## Summary

> 🐟 Elevate your aquarium’s vibe with flawless pH balance!

## Quick Answers

- **What is this?** API pH UP Freshwater Aquarium Water pH Raising Solution for fish,4-Ounce Bottle, Brown by api
- **How much does it cost?** £6.42 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/12774984-api-ph-up-freshwater-aquarium-water-ph-raising-solution-fish)

## 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

- • **Trusted Legacy:** Over 50 years of API innovation ensures reliable aquarium care.
- • **Fish & Plant Safe:** Gentle, non-toxic solution that protects your aquatic ecosystem.
- • **Precision pH Control:** Easily raise freshwater aquarium pH to ideal levels with measured dosing.
- • **Phosphate-Free Formula:** Keeps your tank clean without promoting unwanted algae growth.
- • **Slow & Steady Adjustment:** Neutralizes acidity gradually to maintain stable water chemistry.

## Overview

API pH UP is a 4-ounce, phosphate-free liquid solution designed to safely raise and stabilize the pH level in freshwater aquariums. Ideal for maintaining optimal water conditions for a variety of tropical fish and plants, it neutralizes acidity gradually without promoting algae growth. Trusted by aquarists for over 50 years, this product ensures a healthy, vibrant aquatic environment with easy weekly adjustments.

## 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 UP Freshwater Aquarium Water pH Raising Solution raises 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 growth and help control and cure fish s 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 great - works great raising my aquarium ph water in my area has very low ph put a little in my tank each weak to keep my ph stable
Review: Great product great price - Work in my fish tanks Love this product

## Features

- Contains one (1) API pH UP Freshwater Aquarium Water pH Raising Solution 4-Ounce Bottle
- Raises freshwater aquarium water pH with a phosphate-free formula
- Does not promote growth with pH adjustments and is safe for plants and fish
- Slowly neutralizes acidic substances that cause low water pH
- Test water weekly and use to correct pH level in freshwater aquariums

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0002AQMVO |
| ASIN  | B0002AQMVO |
| Allergen Information | Apple Free |
| Best Sellers Rank | #8,549 in Pet Supplies ( See Top 100 in Pet Supplies ) #59 in Aquarium Water Treatments |
| Brand Name | API |
| Customer Reviews | 4.6 4.6 out of 5 stars (3,625) |
| Date First Available  | June 15, 2004 |
| Department  | Unisex-Adult |
| Global Trade Identification Number | 00317163030318 |
| Is Discontinued By Manufacturer  | No |
| Item Form | Liquid |
| Item Type Name | Aquarium pH adjuster |
| Item Weight | 0.3 Pounds |
| Item model number  | 31C |
| Liquid Volume | 4 Fluid Ounces |
| Manufacturer | Mars Fishcare |
| Manufacturer  | Mars Fishcare |
| Manufacturer Part Number | 31C |
| Manufacturer recommended age  | 1 month and up |
| Model Number | 31C |
| Pet Type | Fish |
| Product Dimensions  | 1.5 x 1.5 x 5.25 inches; 4.8 ounces |
| Target Species | Fish |
| UPC | 317163030318 |
| Unit Count | 118 Milliliters |

## Product Details

- **Brand:** API
- **Item Form:** Liquid
- **Item Weight:** 0.3 Pounds
- **Liquid Volume:** 4 Fluid Ounces
- **Manufacturer:** Mars Fishcare

## Images

![API pH UP Freshwater Aquarium Water pH Raising Solution for fish,4-Ounce Bottle, Brown - Image 1](https://m.media-amazon.com/images/I/610GEsBLa3L.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: How long after using do you re- test to see how much the pH went up?**
A: We would recommend waiting about a half-hour in order for the water to fully circulate so that you get an accurate reading. If you have a very large system or very little flow, you may want to wait 1-2 hours. You are safe to re-dose at that point as long as you have not changed more than 0.2 in pH, which is the maximum we recommend changing within a 24 hour period to reduce fish stress. If you have any other questions, feel free to reach out to us at 1-800-847-0659 or APITechServices@effem.com

**Q: Can this be used in a tank with invertebrates?**
A: Yes. Many years ago this was labeled for ponds

**Q: This should be fine for a Brackish tank?**
A: You can use it however the KH of a brackish tank might prevent you from lowering the ph.  Please contact API at 1-800-847-0659 and we can help.

**Q: does this come with both ph up and down? Or just one of the two?**
A: Just one bottle,ph up!

## Customer Reviews

### ⭐⭐⭐⭐⭐ works great
*by S***N on January 12, 2026*

works great raising my aquarium ph water in my area has very low ph put a little in my tank each weak to keep my ph stable

### ⭐⭐⭐⭐⭐ Great product great price
*by T***N on January 14, 2026*

Work in my fish tanks Love this product

### ⭐⭐⭐⭐⭐ Easy to use & effective
*by P***Z on April 16, 2024*

Impressive product as it immediately helped increase my ph . Added in limited dosage as pkg suggested . Too quick a ph change probably not good for the fish so use intelligently . My ph had been low and caused cloudy conditions , but this solved that and clarity returned with normal ph .

## Frequently Bought Together

- API pH UP Freshwater Aquarium Water pH Raising Solution for fish,4-Ounce Bottle, Brown
- API TAP WATER CONDITIONER Aquarium Water Conditioner 16-Ounce Bottle
- API STRESS COAT Aquarium Water Conditioner 16-Ounce Bottle

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*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-05-24*