Marineland Precision Heater, 300 Watt

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$41.47 (-20%) Chewy Price
$51.79 List Price
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About This Item

Details

  • Submersible heater designed to maintain a comfortable environment in your aquarium.
  • Features an adjustable temperature dial with a high-visibility temperature display.
  • Automatically turns off if the temperature rises above the internal pre-set and will turn back on once it cools down.
  • Flattened mesh heating element surrounds a mica core for superior heat transfer.
  • Includes a mounting bracket to securely attach to glass for convenience.

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Questions & Answers

9 Customer Questions

is this good for a 120 gal tank

Answer by Chewy • Feb 18, 2022
The 50 watt size is recommended for aquariums up to 12 gallons. The 75 watt size is recommended for aquariums up to 20 gallons. The 100 watt size is recommended for aquariums up to 29 gallons. The 150 watt size is recommended for aquariums up to 40 gallons. The 200 watt size is recommended for aquariums up to 55 gallons. The 250 watt size is recommended for aquariums up to 70 gallons. The 300 watt size is recommended for aquariums up to 80 gallons. The 400 watt size is recommended for aquariums up to 125 gallons.

Will the 400 watt be okay for a 75gal or is 300 watt more ideal?

Answer by Chewy • Nov 26, 2019
When you are in between recommended tank sizes, it is recommended to choose the larger of these heaters and program the heat to a suitable level for your aquatic environment.

Is the whole heater able to be submerged including the dial?

Answer by Chewy • Oct 29, 2019
The whole heater is submersible, including the dial.

can you use in a pond outside

Answer by Chewy • Nov 14, 2019
This heater is designed for indoor aquarium tanks only.
Reviews
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3.2
Rated 3.2 out of 5 stars
111 Ratings
Terms & Conditions

74 Customer Reviews

Rated 1 out of 5 stars
By Sarah on Nov 6, 2025

All my fish are dead

The setting was set 79. I came home and my fish are dead. The thermometer says it was 100! Wow. I had a bad feeling. Sucks that it killed my fish I feel so bad

The setting was set 79. I came home and my fish are dead. The thermometer says it was 100! Wow. I had a bad feeling. Sucks that it killed my fish I feel so bad they were literally cooked. Don’t buy

Rated 3 out of 5 stars
By Nicholas on Aug 5, 2025

Overheated Tank

I turned up the dial to 84f to help treat an ich infestation but when I checked on them in the morning all 10 of my tetras were dead and the glass thermometer read

I turned up the dial to 84f to help treat an ich infestation but when I checked on them in the morning all 10 of my tetras were dead and the glass thermometer read over 90f. It could've been because I was running a 100 watt heater in a 20 gal in the summer but I'd advise caution. Otherwise it's a good standard heater, I've had it for a few months now and there's been no other issues.

Rated 5 out of 5 stars
By Samuel on Jun 5, 2025

Great quality when used correctly

I've read a lot of mixed reviews for this particular kind of heater. I accidentally did mess one of these up what I've found is these put out a lot of heat and are

I've read a lot of mixed reviews for this particular kind of heater. I accidentally did mess one of these up what I've found is these put out a lot of heat and are very sensitive to temperature shifts. This particular kind of heater needs to be unplugged to cool off before changing the water in an aquarium and then needs to be allowed several minutes in the water before plugging back in. Any significant temperature shift seems to damage the seal and let moisture into the electronic parts. So in my opinion these are great as long as they are treated with care.

Rated 5 out of 5 stars
By Jim on May 2, 2025

Best aquarium heater

It is accurate and adjustments of setting is easy. Set it little by little. Best heater at an economical price

It is accurate and adjustments of setting is easy. Set it little by little. Best heater at an economical price

Rated 5 out of 5 stars
By Linda on Feb 17, 2025

It is like the one I had for many years....good quality

It is keeping the temperature in my aquarium at the needed temperature

It is keeping the temperature in my aquarium at the needed temperature

Rated 5 out of 5 stars
By Rodriguez on Jan 19, 2025

High quality Well made unit Excellent packaging

Company has a great reputation Delivery was fast, on time and no other problems

Company has a great reputation Delivery was fast, on time and no other problems

Rated 5 out of 5 stars
By James on Mar 20, 2025

Outstanding

It’s always a pleasure ordering from Chewy

It’s always a pleasure ordering from Chewy

Rated 5 out of 5 stars
By kurt on Feb 18, 2025

built in temp display

works great, fish swim better in properly heated tank

works great, fish swim better in properly heated tank

Rated 1 out of 5 stars
By Barbara on Feb 24, 2025

Lasted maybe a week, quit working

guess it was too cheap to be for real..

guess it was too cheap to be for real..

Rated 1 out of 5 stars
By David on Jan 24, 2025

Terrible heater

Both broke within 3 days of use.

Both broke within 3 days of use.