Finnex TH Deluxe Titanium Heating Element with Plastic Guard

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Titanium heating tubes are virtually unbreakable, and corrosion resistant allowing the use in salt or freshwater aquariums. The titanium housing will resist damage a traditional heater would normally encounter while also providing another level of protection with the use of a plastic guard which helps keep other pieces of equipment and livestock from coming in direct contact with the heating tube.

The Finnex TH series of heating tubes do not come with any type of temperature control. We suggest an external heater controller like the Finnex HC-820M or Finnex HC-810M for saltwater systems, or the InkBird WiFi Controller for all systems. Any temperature control device will work, the heaters only require a grounded outlet to plug into.

Three Sizes Available:

  • 300W Deluxe – 40-80 Gallon tanks
  • 500W Deluxe – 70-130 Gallon tanks
  • 800W Deluxe – 140-265 Gallon tanks


Quick Compare - Finnex Deluxe Titanium Heating Tubes

Model Amperage @ 115V Recommended Tank Size (Gallons) Powder Cord to Wall Heating Tube
TH-300 300W 2.7 A 40-80 4 ft 10"
TH-500 500W 4.5 A 70-130 4 ft 14"
TH-800 800W 9 A 140-265 4 ft 16.5"


  • Resists corrosion
  • Virtually unbreakable
  • Fast heating
  • Requires heating controller to operate

*Note: This is a heating element only. Requires Separate Temperature Controller

More Information
Included Mounting Suction Cup
WiFi No
Power Cord Length 4 Feet
Temperature Control Controller (Separate)
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Product Questions

I see these only have a four foot power cord. Would it be alright to use an extension cord to reach my apex?
Question by: Greg Carley on May 17, 2022, 10:17 AM
Thank you for your question. It may be possible to utilize an appropriately rated extension cord for your heater. You will also want to make sure the connection between the power cord and element will stay dry. If this is not possible you may want to look into a waterproof covering for the connection to prevent damages. As a side note, it is recommended to use this element with a controller in addition to the Apex. This additional controller may get you the cord length you desire to the Apex without an extension.

ATTENTION APEX USERS: Note, if pairing our controlled heater series with an Apex controller, users must set the Finnex controller at their desired temperature and the Apex a degree higher for secondary protection. This is to avoid damaging power spikes and unneeded relay stress on both the Finnex controller and Apex power bar components.
Answer by: Rick Pucciarella (BRS Staff) on May 17, 2022, 12:11 PM
What is the outside diameter of the plastic guard?
Question by: Charles on Feb 26, 2018, 4:47 AM
Hi there,
Thank you for reaching out.
The outside diameter of the plastic guard is 1.13 inches.
Please let us know if you have any other questions.
Have a great day!
Answer by: William Glenn on Mar 1, 2018, 4:19 PM
I already have the 300W heater and think it is great. I am upgrading to a 120 gallon tank with ~250 gallons total system volume. If I purchase another heater, should I have them plugged into an extension cord and run that to a single Apex outlet, or should they be run to separate outlets for redundancy's sake? I have never ran two heaters at once. Would a backup heater be required if I have two heaters?
Question by: Mark on Nov 17, 2017, 4:59 PM
We recommend using separate outlets on a controller for a dual heater set-up. I personally like to program one to turn on at say 78 degrees, and then the second one at 77.8 and then the first heater would turn off at 78.4 and the second heater at 78.3. That way it will help keep the power from spiking and also the single heater will generally heat the vast majority of the tank and the second will be more of a backup. That method also helps keep the temp from swinging dramatically.
Answer by: Charlie on Nov 18, 2017, 8:03 AM
Does the whole heater have to be completely under water? I have about 8 inches of space but could angle it a bit. The problem is if for some reason my ato fails or runs out of water some of the heater might be left in the air...

Question by: Joshua Huggins on Jan 25, 2017, 9:42 AM
Great question! You could feel comfortable with about 1" of the heater being exposed to air, but if it becomes completely exposed, it could overheat the element and damage the heater. :-)
Answer by: Randy on Jan 28, 2017, 10:32 AM
I have a 90 gallon do I need to go with the 500W?
Question by: Jeremy on Jan 6, 2017, 11:59 PM
Great question! A 300W heater is rated for a tank of 100gal or less, however the ambient temperature in your room will affect it's ability to maintain a higher temp. Honestly, if you have the space for a 500W heater I would purchase it. :-)
Answer by: Randy on Jan 11, 2017, 12:59 PM
i have a 300 gallon which do i use.
Question by: roberto on Nov 20, 2016, 2:35 PM
Great question! We recommend 2.5watts/gallon, which would be about 750w for you tank. I would recommend the 800w heater and possibly another one for backup redundancy. :-)
Answer by: Randy on Nov 21, 2016, 6:51 PM
I've several of these, in various sizes, with external controller. They all develop a light-brown, crusty coating on the bottom over the course of several months. This coating is hard and doesn't seem to want to come off. The units still work, but how do I clean them to prevent this from hurting the heaters, if the deposits get worse? Can I sand it off? Can I use some vinegar or stronger acid or base? Can I scrape them?

I'd say a contributing factor is that the manufacturer says to lay them on the bottom horizontally...it is in this position that it's close to whatever I have on the bottom, which may not help. Must these be horizontal on the bottom?


Question by: Larry on Nov 12, 2016, 2:04 AM
Hey there,
This crusty buildup you describe sounds like a precipitate which often does form around heaters. Due to the direct proximity to the heater, particularly at the point where it is near the bottom, this increases precipitation of the minerals in the saltwater, and this can often be seen on other heater types as well. To remove this, a 50/50 mix of white vinegar in a bath for 30-60 minutes will generally dissolve the buildup and allow you to get it cleaned up and back in like-new condition!
Answer by: Zack on Nov 14, 2016, 4:38 PM
I am heating 240 gallon salt water fish tank + 40 gallon sump controlled by apex which heater do you recommend and where should I place the heater in main tank or in the sump?
Question by: Gabriel Katz on Oct 5, 2016, 11:00 AM
Great question! We recommend 2.5W per gallon for proper heater sizing. That would be approximately 650W of heater for your setup. You may need more than one or two heaters. Really anywhere you put the heaters in the water column is fine. I wouldn't recommend putting the heaters in the same chamber as your Apex temp probe. :-)
Answer by: Randy on Oct 14, 2016, 10:31 AM
Is there any kind of indicator on the heater itself, to visually show when it is on or off?
Question by: Fawn on Jul 16, 2016, 1:30 PM
Hi Fawn,
The Titanium Heating Tubes do not actually have any status indicator on the heaters or the electrical cord. If you wanted to have an indicator light, you could share the outlet that the heater is plugged into with a small LED light to indicate that it is on.
Answer by: Charlie on Jul 18, 2016, 8:45 AM
If connecting two 300w heaters to the reef keeper lite, would they both plug into the same controlled outlet via a 2-to-1 adapter or would they each take up their own controlled outlet on the controller?
Question by: David Danis on May 24, 2016, 10:18 PM
Great question! This should work just fine.
Answer by: Carter on May 26, 2016, 11:52 AM
I am heating a 125 gallon aquarium controlled by an apex system. Would you guys recommend the 500w or 800w? Also I could not find anywhere that stated whether or not this heater is full submersible?
Question by: Jon Bates on May 19, 2016, 10:58 PM
Great question! I would recommend the 800watt, and they are fully submersible.
Answer by: Carter on May 24, 2016, 11:51 AM
I have only 12 inches in my sump for a heater and my water volume is around 150 gallons. Would using 2 300watt heaters work? I will have them connected to my Apex.
Question by: Jack Carpenter on Apr 13, 2016, 9:31 PM
Great question!
Two of the 300 watt heaters will work great on a 150 gallon tank at the minimum wattage for heaters. Controlling with the apex will help the heaters to run at the correct temperature. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 19, 2016, 10:22 AM
How would I hook the 500watt heater to the apex?
Question by: ramon rivera on Mar 24, 2016, 3:02 PM
Great question!
You can plug the heater into outlet 4 or 8 for perfect control. The temp probe can be assigned to the outlet and turn the heater on and off. Feel free to let us know if you have any further questions!
Answer by: Connor on Mar 24, 2016, 3:57 PM
Would this be safe to use in an acrylic sump?
Question by: Andrew on Mar 16, 2016, 7:58 AM
Great question!
When used in conjunction with a temp controller or aquarium controller this will work great! Feel free to let us know if you have any further questions!
Answer by: Connor on Mar 16, 2016, 11:23 AM