Octo Strong Magnetic Aquarium Heater Holder

(62 customer reviews)


Don’t fall for wimpy magnets!  I revolutionized the usage of high-powered magnets in our industry!


Let’s face it….suction cups, well, suck! And then they pop off. That’s why my products feature super strong neodymium magnets. One thing that always bothered me about heaters is that they come with suctions cups that eventually stop doing their job. Well, now you don’t have to worry about that. These Octo Strong Heater Holders™ are made from 1/4″ clear cell cast acrylic, will hold on glass up to 3/8″ thick and feature o-rings made of a material that can withstand the elements of a saltwater tank.

  • Available in both single and double configurations, for standard round heaters (up to 1″ diameter) as well as the flat Cobalt Neo-Therm heaters.
  • Will work titanium and plastic covered heaters as well!
  • External magnet can be submerged!
  • Comes with O-Rings (Not used with Cobalt).

Approximate sizes:

Double Round: 5″ wide x 5″ tall x 1 3/4″ deep
Single Round: 5″ wide x 2 3/4″ tall x 1 3/4″ deep
Double Cobalt: 4 1/2″ wide x 2 3/4″ tall x 3″ deep
Single Cobalt: 4 1/2″ wide x 2 3/4″ tall x 1 3/4″ deep

External magnet needs about .625″ for clearance.

(Heaters not included)

I use N52 neodymium magnets. Rare earth magnets are not reef safe on their own, so I fabricate custom acrylic pods that encapsulate the magnets and keep them away from your water. Please visit the magnet warning page for more information on these magnets.


My products are made to order, custom! Please allow up to 10 business days for fabrication time for most products. Because my products are made to order, fulfillment time can rarely take longer. Full custom orders can take up to four weeks to complete. Please let me know ahead of time if this may be an issue. Shipping prices listed are to the contiguous U.S. Please contact me if you live elsewhere and want a shipping quote. Because my products are handmade and/or hand assembled, there may be small irregularities (fingerprints, marring, hair, etc) which will not effect the performance of your product.

Plastics are fragile which can break and scratch easily. Always handle with care. Surface can be cleaned with a very diluted soapy water mixture and a soft microfiber cloth.

This product is warranted to be free of defects for the lifetime of the product. We will, at my discretion, repair or replace your product at no charge during this period (See the Warranty page for more info.)

Additional information


Round, Cobalt


Single, Double

62 reviews for Octo Strong Magnetic Aquarium Heater Holder

  1. Amanda Cerrato (verified owner)

    So far so good!! These magnetics are CRAZY STRONG!!!! I purchased 2 of these holders to use with 300w Titanium heaters and so far I’m very pleased with them. I was sick and tired of suction cups moving around & “un-suctioning” during tank cleaning time – not an issue anymore! Thank you!

  2. Mike S. (verified owner)

    simply awesome! helped organize and maximize the space in my sump. magnets work great!

  3. Ryan Fletcher (verified owner)

    Magnets don’t move heaters stay in place. Very happy with it

  4. Robert Paterson (verified owner)

    Best way to keep your heaters lined up.

  5. Amanda C. (verified owner)

    Love this holder – I’ve ordered 3 from Matt and they all function perfectly. I use titanium heaters in my Discus tanks and was concerned about the temperatures melting the plastic but I haven’t had one issue. My tanks are set anywhere between 82F-90F and have not had one issue with the holder warping or melting. All 3 holders are still in perfect shape after almost 1 year of use!

  6. Amanda C. (verified owner)

  7. Brennen (verified owner)

  8. Anonymous (verified owner)

    Great product. Well built and the magnetic is strong to hold 2 heaters.

  9. dennis (verified owner)

    Great product. Strong and quality made.

  10. Anonymous (verified owner)

    Great Stuff Solid Practical Funtional

  11. KEVIN (verified owner)

    Fast shipping!

  12. Dirk (verified owner)

    Great product, well built, customer service excellent

  13. Clarence (verified owner)

    Works great with 2 BRS titanium heaters!,,

  14. Debbie Grissom (verified owner)

    High quality item. The magnet is very strong. Very pleased with my purchase!

  15. Justin (verified owner)

    Ridiculously strong magnet, and everything stays nice and snug in my sump.

  16. Erik (verified owner)

    Amazing for my sump, have two titanium heaters in it and hasn’t moved from where I put it, and running 4000gph over them!!!

  17. Mark B. (verified owner)

    Strong Magnet, easy to use, quick shipping. will buy another when needed

  18. Alex S. (verified owner)

    I have one for my Cobalt heater and a round one for an Eheim heater. Makes life easy. Beautifully constructed and zero worries about the magnet. That’s all I can ask for.

  19. Alexx LeVasseur (verified owner)

    I love these heater holders. I had some that were by a big manufacturer and although they were acceptable they limited how big the heater could be so I had to remove my titanium heaters from their sleeve in order to force them to fit. This one allows for various sizes and I am able to keep my heaters in their sleeves. Another thing they are useful for is on my freshwater tanks I have changed the output of my Fluval FX6’s and 4’s to use spray bars and the rubber stoppers that held them in place were forever sliding and breaking down overtime causing black sludge rubber pieces…it was gross. These heater holders are perfect for holding the spray bars in place. Great product and quality!

  20. Bennett (verified owner)

    Top quality, superb communication.

  21. Jeffrey S (verified owner)

    Holds my two titanium heaters perfectly, very nice quality and machining. Super fast order turn around and shipping
    Thanks for a great product

  22. DONALD CHESSER (verified owner)

    Very awesome product! It keeps my heaters perfectly in place in my sump. Great quality as well. I’m now ready to see any a lid from this company too.

  23. Kye G. (verified owner)

    Awesome product. Fast service.

  24. John (verified owner)

    Works as advertised. The external magnet is large, not a negative as it definitely holds the heaters. The size does limit where it can be placed. Stock Red Sea 525XL sump does not allow for the heaters to be placed in the rear compartments due to the lack of space between the sump and cabinet wall. This is not a deal-breaker just need to plan ahead. Thick acrylic and bands are strong. Worthwhile purchase.

  25. John Kiernan (verified owner)

    Great product simple design and the strongest magnets I’ve seen used. Held great on my acrylic sump.

  26. WILLIAM L. (verified owner)

  27. Troy C. (verified owner)

    Great heater mag mount , tight firm fit in sump for my BRS 600w titanium heater. Very secure magnet connection. I have tried several mounts and octo has the best one out there. Nice heavy duty build . A+++

  28. Steve B. (verified owner)

    Awesome product. Just what I wanted

  29. Anonymous (verified owner)

    Solid Product from a solid company!

  30. Rodney C. (verified owner)

    This is a great product, the quality is amazing. It is exactly what I needed to secure my heaters in place.

  31. David (verified owner)

    Ordering process was painless. Product arrived very well packed and great quality craftsmanship. Magnets are extremely strong and sealed well. Very happy I ordered this to fit my heaters in my sump and be properly wire managed.

  32. Joe W. (verified owner)

    Love these guys products, top quality!!

  33. Kevin T. (verified owner)

    I am very happy with the dual magnetic heater holder. Excellent quality. I have peace of mind knowing my heaters are exactly where I mounted them and not floating around because the suction cups didn’t hold. Spend a few extra dollars and save your aquarium from disaster. Thanks Octo Aquatics!

  34. Tammy Mcgrath (verified owner)

    Very happy! Well made and fits my two 300w heaters perfectly.

  35. William W. (verified owner)

  36. James Adams (verified owner)

    Good value for the price. Holder is well made and magnets hold strong. I don’t have to worry about heater not staying in place anymore

  37. Andrew W. (verified owner)

    Product works and fits as expected. Excellent build and quality

  38. James A. (verified owner)

    Great product. Solidly built. This is my second order after I was impressed with first one.

  39. David E. (verified owner)

    Got two of these for my new glass sumps. They look amazing! These easily hold two BRS titanium heaters (200,300w) on 8mm glass. The ‘dry’ side is reef safe; I have these on the baffle before my return section. To heater is primary, bottom heater is back up.
    Place your wet side where you want it, then put the dry side flat on the sump several inches away…. Slide into position so you don’t get the scare you to death slam if you try to put powerful magnets on top of one another. My dry side is wet,too! Magnets clearly visible, sealed in clear pods. ( Like Vertex, GHL) Quality construction that let’s you know your magnets are dry and your tank safe.
    Nice to have an original design in this day of copy and mass produce aquarium accessories.

  40. Donald Laws (verified owner)

    Nice workmanship works great THANK YOU!

  41. Daniel (verified owner)

    simply the best , love this product

  42. Neil (verified owner)

    Solid build and keeps heaters off the sump floor to prevent possible melt since suction cups are destined to get hard and fail. Strong magnets keep the holder in place.

  43. Anthony Collazo (verified owner)

    Absolutely perfect fit for my heaters! I always dreaded leaving heaters in the sump for fear of the suction cups detaching, and I was right. One heater detached and landed on my skimmer. The heater then began melting down the skimmer body. Fortunately, I was able to catch it before the skimmer was damaged. This heater holder put the worry to rest, permanently. 5 stars- Absolutely

  44. Daniel Elway (verified owner)

    Heater holder is perfect. Got the double holder works awesome and looks great!! This is my second product from Octo and I will be purchasing a few more things in future. Quality is top notch.

  45. Alen (verified owner)

    Get another one for sure

  46. Simon Stirling (verified owner)

    After trying every commercially available holder in the industry, FINALLY!

  47. JOYDEEP G. (verified owner)

  48. Anonymous (verified owner)

    Excellent. Holds quite well even through 12mm glass.

  49. Anonymous (verified owner)

  50. Rogelio (verified owner)

    So far I am happy with the holder. Quality wise it is sturdy and easy to install in the sump. Tue magnet sticks well and attached very hard. It helps my sump organized.

    The seller is very responsive and helpful.

  51. Michael G. (verified owner)

    This is my third Octo Strong Heater Holder, I have one in each of my 3 saltwater aquariums and wouldn’t use anything else to hold the heater. Highly recommend these.

  52. Don Pyzel (verified owner)

    These are amazing, best setup I found

  53. robert p. (verified owner)

    Perfect for what I need. Magnet is very strong, no more wandering heaters.

  54. Cliff D. (verified owner)

  55. Justin (verified owner)

  56. William W. (verified owner)

  57. Cesar V. (verified owner)

    Simply awesome like all the other stuff Matt builds. This is the perfect heater holder for any sump. Magnets are extremely strong, watch your fingers!

  58. William (verified owner)

    Great product and fast shipping!

  59. Rob A. (verified owner)

    looks great, and the suction cups that came with the heater weren’t reliable this magnetic holder is enclosed waterproof and The acrylic engineering looks great

  60. Jeff Anderson (verified owner)

    Holds two of my 300w finnex titanium heaters perfectly and they magnet is perfectly sized doesn’t move around, but not so much that it’s a pain to pull it out

  61. John P. (verified owner)

    This is the second unit I have purchased. The magnet is strong enough to hold two 300w Eheim heaters in place with a recirculating pump pushing against it. The O-rings show no degradation after 2.5 years on my first holder. This is not the slimmest holder as it was designed for function, not some minimalistic desire.

  62. Jason H. (verified owner)

    Excellent construction and quality. Fast shipping and Octo Aquatics was a pleasure to work with.

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