---
product_id: 52830982
title: "Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon"
brand: "freesea"
price: "¥5785"
currency: JPY
in_stock: true
reviews_count: 9
category: "Freesea"
url: https://www.desertcart.jp/products/52830982-aquarium-fish-tank-heater-50w-small-submersible-turtle-heater-adjustable
store_origin: JP
region: Japan
---

# 50W powerful heating Dual auto shut-off safety Adjustable 63℉-94℉ temp range Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon

**Brand:** freesea
**Price:** ¥5785
**Availability:** ✅ In Stock

## Summary

> 🌊 Keep your aquatic friends thriving with precision warmth and peace of mind!

## Quick Answers

- **What is this?** Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon by freesea
- **How much does it cost?** ¥5785 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/52830982-aquarium-fish-tank-heater-50w-small-submersible-turtle-heater-adjustable)

## Best For

- freesea enthusiasts

## Why This Product

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

## Key Features

- • **Real-Time LED Display:** Instant digital temp readout and error alerts keep you informed at a glance.
- • **Smart Safety Features:** Auto shut-off when exposed or overheated keeps your fish safe 24/7.
- • **Compact & Submersible Design:** Sleek glass heater fits discreetly in 1-10 gallon tanks without clutter.
- • **Precision Temperature Control:** External controller lets you dial in the perfect aquatic climate with ease.
- • **Versatile for Fresh & Saltwater:** One heater to rule all tanks—betta, turtles, saltwater, or freshwater.

## Overview

The FREESEA 50W Aquarium Fish Tank Heater is a compact, submersible device designed for 1-10 gallon tanks. Featuring an external adjustable controller with a 63℉ to 94℉ range, it ensures precise temperature management for bettas, turtles, and other aquatic pets. Dual safety auto shut-off protects against overheating and dry exposure, while the LED display provides real-time temperature and error codes. Suitable for both freshwater and saltwater environments, this heater combines reliable performance with user-friendly controls and robust safety features.

## Description

desertcart.com: FREESEA Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon : Pet Supplies

Review: Great - I recently purchased the FREESEA Aquarium Fish Tank Heater, and it has been a fantastic addition to my aquarium setup! This 50W submersible heater is specifically designed for small tanks, and it’s perfect for maintaining the right temperature for my betta fish and other aquatic friends. One of the standout features of this heater is its adjustable temperature external controller. Setting the desired temperature is a breeze, and the clear display allows me to monitor it at a glance. I’ve noticed that my fish are much more active and healthy since I started using this heater, which I attribute to the consistent temperature it maintains. The design of the heater is compact and sleek, making it easy to fit into my 1-10 gallon tank without taking up too much space. It’s also submersible, which means I can place it exactly where it’s needed for optimal heating. The installation process was straightforward, and I appreciated the included suction cups that keep the heater securely in place. I was also impressed by how quickly the heater warms up the water. It doesn’t take long to reach the desired temperature, and I feel confident that my fish are comfortable and safe. The heater has built-in safety features, such as over-temperature protection, which provides additional peace of mind. What I love most is its versatility; this heater is suitable for both freshwater and saltwater tanks, making it a great option if I decide to diversify my aquarium in the future. The quality of the materials used feels solid, and I expect it to last a long time. Overall, the FREESEA Aquarium Fish Tank Heater is an excellent choice for anyone with a small aquarium. It offers reliable heating, easy temperature control, and peace of mind for fish owners. I highly recommend this heater for keeping your aquatic pets happy and healthy!
Review: Good Buy - So Far, So Good. Set up was easy. Heater has been running for over a week with no issues. Digital Display is nice and easy to read.

## Features

- FREESEA Aquarium Heater: 50w betta fish heater, voltage: 110~120V, is suitable for use in 1-10 gal betta fish turtle tanks and aquariums. The power cord is 5ft, long enough for indoor use
- Double Safety Protection: When the top part of the turtle tank heater is out of water it will auto shut off. When the actual water temperature is higher than 94°F, it will auto activate the overheating protection and stop heating
- External Controller: The betta fish heater is adjusted by an external controller, which you can mount on the outside edge of the tank. It’s convenient to adjust temperature that range from 63℉ to 94℉
- LED Temperature Display: Digital led temperature display shows the real-time temperature and error code on the screen. When the mini aquarium heater is heating, there indicator light above the digit is on red
- Excellent Service: The Heater of the FREESEA operate very stably under Fish Tank. If you have any questions about the Heater you received, please feel free to contact us at any time. 24-Hour Professional After-Sales Service

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B075PSPCNY |
| ASIN  | B075PSPCNY |
| Best Sellers Rank | #14,786 in Pet Supplies ( See Top 100 in Pet Supplies ) #39 in Aquarium Heaters |
| Brand | FREESEA |
| Brand Name | FREESEA |
| Color | Submersible Heater with External Controller |
| Customer Reviews | 4.1 4.1 out of 5 stars (8,810) |
| Date First Available | September 17, 2017 |
| Date First Available  | September 17, 2017 |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 2.5 x 1.5 x 3.5 inches |
| Item Length | 3.5 Inches |
| Item Package Dimensions L x W x H | 5.55 x 3.7 x 2.8 inches |
| Item Weight | 8.1 ounces |
| Item model number | FS28-50W |
| Item model number  | FS28-50W |
| Manufacturer | FREESEA |
| Manufacturer  | FREESEA |
| Material | Glass |
| Product Dimensions  | 2.5 x 1.5 x 3.5 inches; 8.15 ounces |
| Size | 50W(1-10gallon) |
| Target Audience Keyword | fish, fish tortoise |
| UPC | 722970219243 |
| Voltage | 110 Volts |
| Wattage | 50 watts |

## Product Details

- **Brand:** FREESEA
- **Color:** Submersible Heater with External Controller
- **Item Length:** 3.5 Inches
- **Material:** Glass
- **Voltage:** 110 Volts

## Images

![Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon - Image 1](https://m.media-amazon.com/images/I/716knQX-94L.jpg)

## Questions & Answers

**Q: No directions came with my heater....How can I adjust the temp so that it actually sticks?**
A: Use the Button by the outlet side and then press it, it will start to flash press until your at the proper temp then leave it. It will adjust itself

**Q: Can i adjust it to set to 78 degrees F for a betta fish?**
A: Dear customer, 78 ℉ is ≈ 26℃ , designed temperature for this heater is 15~34℃，normally, suitable temperature for betta fish is 24~30℃（75~86℉）, we suggest you ask local fish store for more details.

**Q: What type of plastic is it made of?**
A: The Plastic is durable, does no appear to be fiberglass filed plastic. How ever the one I purchased is sitting in a box it didn't last much more than a month. an alert message flashed and I removed it as soon as I noticed it. Replaced it with a Cobalt Neo-Therm Heater.

**Q: Why is this Heater flashing 00?  Tried unplugging and resetting- still does not work.**
A: It flashes till you set the temp you want then it stops. If it keeps flashing then you need to contact seller and send it back.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great
*by C***C on November 5, 2024*

I recently purchased the FREESEA Aquarium Fish Tank Heater, and it has been a fantastic addition to my aquarium setup! This 50W submersible heater is specifically designed for small tanks, and it’s perfect for maintaining the right temperature for my betta fish and other aquatic friends. One of the standout features of this heater is its adjustable temperature external controller. Setting the desired temperature is a breeze, and the clear display allows me to monitor it at a glance. I’ve noticed that my fish are much more active and healthy since I started using this heater, which I attribute to the consistent temperature it maintains. The design of the heater is compact and sleek, making it easy to fit into my 1-10 gallon tank without taking up too much space. It’s also submersible, which means I can place it exactly where it’s needed for optimal heating. The installation process was straightforward, and I appreciated the included suction cups that keep the heater securely in place. I was also impressed by how quickly the heater warms up the water. It doesn’t take long to reach the desired temperature, and I feel confident that my fish are comfortable and safe. The heater has built-in safety features, such as over-temperature protection, which provides additional peace of mind. What I love most is its versatility; this heater is suitable for both freshwater and saltwater tanks, making it a great option if I decide to diversify my aquarium in the future. The quality of the materials used feels solid, and I expect it to last a long time. Overall, the FREESEA Aquarium Fish Tank Heater is an excellent choice for anyone with a small aquarium. It offers reliable heating, easy temperature control, and peace of mind for fish owners. I highly recommend this heater for keeping your aquatic pets happy and healthy!

### ⭐⭐⭐⭐⭐ Good Buy
*by B***K on December 22, 2025*

So Far, So Good. Set up was easy. Heater has been running for over a week with no issues. Digital Display is nice and easy to read.

### ⭐⭐⭐⭐ Great heater
*by R***N on January 21, 2026*

This product works well. It’s small and heated the water quickly and keeps the temp. I am using the heater for a turtle habitat.

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**Shop now:** [https://www.desertcart.jp/products/52830982-aquarium-fish-tank-heater-50w-small-submersible-turtle-heater-adjustable](https://www.desertcart.jp/products/52830982-aquarium-fish-tank-heater-50w-small-submersible-turtle-heater-adjustable)

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-25*