Heater in Sponge Filter? Why Not!

[kahjtheundedicated]

Recently had my HOB filter die, so decided to get creative, and use the power of 3d printing to make a quick sponge filter that can use the intake sponge from my HOB, and would fit nicely in the corner. Things escalated quickly, and I decided I could probably design an "airstone" into the base. Then I looked at it and thought "man I can probably fit my heater in there", so I did.

Here is a cross section of the base and airstone section of the sponge filter, followed by a top-down of that section in solidworks.

 

To hold the heater, I just designed some super minimal holders that will snugly slide over the heater and inside the sponge filter tube, without blocking too much flow of air or water.

Here are a couple pics of the finished print and assembly, and it inside the aquarium. I just used gravel and sand to weigh it down.

If anybody is interested and happens to have the same ~20yo unbranded submersible heater with a 17mm OD and some foam with a ~25-28mm ID, I'd be more than happy to upload the solidoworks files and/or stl files.

Thanks for reading!

[Minanora]

This, is epic! Have you put it on thingiverse? I would love to print this for fun. I may have a heater that fits even, gotta bust out the calipers and check!

What filament type did you use?

Side note: Be careful heating plastics. Most plastics leach compounds when heated.

[kahjtheundedicated]

Thanks! I used clear petg, which from what I've read is about as aquarium safe as it gets. Not sure if it was necessary, but I also put a coat of super glue on exterior surfaces of the "air tube" to avoid leakage.

But yeah I'll post it to thingiverse and @ you when it's up.

 

[Minanora]

Funny the person who has "undedicated" in their name goes and spends at least several hours drafting up, and then several more hours printing out, a custom sponge filter. 😛

[kahjtheundedicated]

Haha yeah, it's from an old D&D campaign when I was in college. Our DM had us roll for our titles. So I became " the undedicated". Could've been worse, we had a wizard whose only good stat was intelligence, and he was "the uneducated".

[CalmedByFish]

This is epic.

But also, I've had 3(?) brands of heater eventually let teeny bits of moisture in from the top seam, where the glass tube met the plastic. I'm pretty sure that IF your heater ends up doing that, this constant water movement will make it happen sooner rather than later. Fingers crossed, but I thought I should give you a heads-up. 

[Minanora]

And... now I'm going to seal all of my backup heaters at that seal. Great observation @CalmedByFish

[CalmedByFish]

On 12/17/2021 at 11:18 AM, Minanora said:

And... now I'm going to seal all of my backup heaters at that seal. Great observation @CalmedByFish

It never occurred to me to do that. I guess the same silicone that's used to seal glass tanks would be good?

[Minanora]

On 12/17/2021 at 10:22 AM, CalmedByFish said:

It never occurred to me to do that. I guess the same silicone that's used to seal glass tanks would be good?

I'm thinking so. In my mind it was either that or epoxy. Silicone seemed the best though. flexible and will be okay with the heater turning on and off. I imagine it will still eventually do as you stated, but will hopefully take longer. I assume that the glass/plastic/rubber is expanding and contracting when the barrel of the heater heats and cools.