---
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: "€ 39.53"
currency: EUR
in_stock: true
reviews_count: 8
category: "Freesea"
url: https://www.desertcart.com.cy/products/52830982-aquarium-fish-tank-heater-50w-small-submersible-turtle-heater-adjustable
store_origin: CY
region: Cyprus
---

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

**Brand:** freesea
**Price:** € 39.53
**Availability:** ✅ In Stock

## Summary

> 🌊 Keep your tank thriving with precision warmth — because your aquatic life deserves the best!

## 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?** € 39.53 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.cy](https://www.desertcart.com.cy/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

- • **Versatile Compatibility:** Ideal for Betta, turtles, saltwater, and freshwater tanks—perfect for your diverse aquatic ecosystem.
- • **Advanced Safety Mechanisms:** Auto shut-off when exposed or overheated ensures peace of mind for your aquatic friends.
- • **Compact & Submersible Design:** Sleek 3.5-inch glass heater fits discreetly in 1-10 gallon tanks without disrupting your aquarium’s aesthetic.
- • **Reliable & Efficient Heating:** Stable 50W power quickly reaches and maintains optimal temperatures, boosting fish vitality and plant growth.
- • **Precision Temperature Control:** Easily set and monitor your tank’s climate with an external LED display and controller for perfect aquatic comfort.

## Overview

The FREESEA 50W Aquarium Fish Tank Heater is a compact, submersible glass heater designed for 1-10 gallon tanks. Featuring an external adjustable controller with a digital LED display, it offers precise temperature settings from 63℉ to 94℉. Dual safety protections automatically shut off the heater if exposed to air or if water temperature exceeds 94℉, ensuring safe and stable operation for Betta fish, turtles, and both freshwater and saltwater aquariums.

## 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 little heater. - Heater works well and is very efficient. I have a 5gal Betta tank with some live plants and betta in it. Its an office tank and set up with plants that would tolerate not being heated. Since setting up the tank I moved into a new position and part of new my office is exposed brick walI, which makes it harder to maintain the temperature. I was looking for something smaller since my tank is small and prefer submerging heaters. I also didn't want to spend a ton of money on it if possible. Since adding this I have noticed my betta is more active and the plants are growing much quicker. Temperature rises quickly to setting and maintains steadily with no adjusting from me. The only negative I would have would be that every 3 or 4 days the thing the sections cups release and I have to stick it to the side of the tank again. However my tank is round and I'm unsure if this is playing into the issue. Instead of having to worry about it coming free and floating to the top of the water I was able to add a small binder clip to the top of the cord which keeps it down in the water if it releases. Again I am unsure if it is due to my tank being round and not flat. Overall this is a great little heater for a small tank!
Review: Great heater for small aquariums - I was a little nervous about this given some of the reviews, but pretty much every aquatic heater on desertcart has a decent amount of 1 star reviews. I'm using this in a 3 gallon tank I use for raising guppy fry until they are large enough to move to the larger aquariums I have for them. This has been amazing! I haven't modified it at all and used it for about a month now and I'm happy to report that every guppy survived. This heater does sometimes vary by 1 degree when the temperature drops below what it is set at but it quickly heats up again to the set temperature and it is never more than 1 degree lower which was not an issue for the babies. Honestly I prefer this to it always keeping the temp higher than what I set it at like some other models do since it pretty much guarantees that it will not cook your fish. None of my fish attempted to go behind the heater, so if I had a Betta I might place some netting around the suction cups on the back as one other reviewer did since Bettas do enjoy resting and hiding. Alternatively, I'd suggest giving your Betta more preferable resting places and hiding spots/keep the tank warm enough so he won't want to go behind the heater.

## 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 | #18,429 in Pet Supplies ( See Top 100 in Pet Supplies ) #36 in Aquarium Heaters |
| Brand Name | FREESEA |
| Color | Submersible Heater with External Controller |
| Customer Reviews | 4.1 4.1 out of 5 stars (8,828) |
| Date First Available  | September 17, 2017 |
| Is Discontinued By Manufacturer  | No |
| Item Length | 3.5 Inches |
| Item model number  | FS28-50W |
| Manufacturer | FREESEA |
| Manufacturer  | FREESEA |
| Material Type | Glass |
| Product Dimensions  | 2.5 x 1.5 x 3.5 inches; 8.15 ounces |
| UPC | 722970219243 |
| Unit Count | 1 Count |
| 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)

## Available Options

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

## 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 little heater.
*by D***E on December 3, 2020*

Heater works well and is very efficient. I have a 5gal Betta tank with some live plants and betta in it. Its an office tank and set up with plants that would tolerate not being heated. Since setting up the tank I moved into a new position and part of new my office is exposed brick walI, which makes it harder to maintain the temperature. I was looking for something smaller since my tank is small and prefer submerging heaters. I also didn't want to spend a ton of money on it if possible. Since adding this I have noticed my betta is more active and the plants are growing much quicker. Temperature rises quickly to setting and maintains steadily with no adjusting from me. The only negative I would have would be that every 3 or 4 days the thing the sections cups release and I have to stick it to the side of the tank again. However my tank is round and I'm unsure if this is playing into the issue. Instead of having to worry about it coming free and floating to the top of the water I was able to add a small binder clip to the top of the cord which keeps it down in the water if it releases. Again I am unsure if it is due to my tank being round and not flat. Overall this is a great little heater for a small tank!

### ⭐⭐⭐⭐⭐ Great heater for small aquariums
*by K***R on March 29, 2022*

I was a little nervous about this given some of the reviews, but pretty much every aquatic heater on Amazon has a decent amount of 1 star reviews. I'm using this in a 3 gallon tank I use for raising guppy fry until they are large enough to move to the larger aquariums I have for them. This has been amazing! I haven't modified it at all and used it for about a month now and I'm happy to report that every guppy survived. This heater does sometimes vary by 1 degree when the temperature drops below what it is set at but it quickly heats up again to the set temperature and it is never more than 1 degree lower which was not an issue for the babies. Honestly I prefer this to it always keeping the temp higher than what I set it at like some other models do since it pretty much guarantees that it will not cook your fish. None of my fish attempted to go behind the heater, so if I had a Betta I might place some netting around the suction cups on the back as one other reviewer did since Bettas do enjoy resting and hiding. Alternatively, I'd suggest giving your Betta more preferable resting places and hiding spots/keep the tank warm enough so he won't want to go behind the heater.

### ⭐⭐⭐⭐ 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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- FREESEA Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon
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*Product available on Desertcart Cyprus*
*Store origin: CY*
*Last updated: 2026-04-23*