DIY Inline Aquarium Heater?

Discussion in 'Pets & Animals' started by Oosh, Apr 18, 2007.

  1. Oosh

    Oosh Member

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    After having an external canister filter (AquaOne CF1200) for the last week, I was thinking why not have an external canister heater?

    I see that there are inline-heaters available for purchase, but in the interest of saving money (and the DIY spirit), why not convert an existing in-tank item?

    Here's my idea (complete with ASCII art) for comment:
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    So basically it's a piece of PVC pipe (90mm dia?) with two end caps, the heater inside, and inlet / outlet fittings.

    I figure it's better upright, and therefore easier to plumb with both fittings up top, so the inlet on the right has a tube running to the bottom of the canister to insure good circulation.

    Edit: Oh and the power cord can exit via the top lid too, with silicone or a grommet to seal it.
    Also by doing the above and using threaded end-caps it can all be disassembled for inspection and cleaning (hooking it up immediately after the filter should lessen the need for that though).
     
    Last edited: Apr 18, 2007
  2. OP
    OP
    Oosh

    Oosh Member

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    30 views, and no comments, am I insane, or perhaps inane?

    Regardless, I'm thinking giving this a go over weekend.
     
  3. thebranded

    thebranded Member

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    i like the idea but the water flow rate would have to be rather slow otherwise the water will not get a chance to heat up? would that mean theres a second pump (if the filter is too fast)?
     
  4. OP
    OP
    Oosh

    Oosh Member

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    Actually I'm think the more flow the better (within reason), provided the water in the canister is being turned over sufficiently.

    If there's localised heating inside the canister, and the new water flowing in form the tank is being pushed right out again, the thermostat will click off and the tank will cool.

    But if the heated water is pushed out, and being replaced with the cooler water from the tank, the thermostat stays on while the water entering is at the desired temp.

    Even the in-tank heaters suggest they be subjected to some flow, the larger the tank the more important that becomes, so you don't have hot and cold zones of water. Which is probably why multiple small heaters are the norm for big setups (haven't seen over 300W for an in-tank heater).

    Perhaps inducing some swirl, or turning that down pipe in to spray bar on to the heater, would improve that situation.

    Even though this is fundamentally opposite to cooling a PC, this is starting to sound like something the guys in Extreme Cooling would have some expertise in...
     
  5. VippiN

    VippiN Member

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    Mate you'll be better off just placing an internal heater by your canister inlet within the tank.
     
  6. OP
    OP
    Oosh

    Oosh Member

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    But I don't want it in the tank.
     
  7. phextwin

    phextwin Member

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    Flow rate is irrelavant to heat flux, the water may spend less time being heated per loop, but it does more loops per unit of time so it all evens out.

    Secondly, your heater set up looks fine. Water can hold a huge amount of heat (~4200 J/Kg/K to quantify) so it takes a long time to heat up, and consequently a long time to cool down. Once heated up, the water temperiture should not vary by much at all.
     
  8. Ace Rimmer

    Ace Rimmer Member

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    I think it would work. Let us know how it goes.
     
  9. R3Dl2ULZ

    R3Dl2ULZ Member

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    i cant see why it wouldnt work. you might have trouble getting the water back into the tank without a secondary pump.
     
  10. TERRA Operative

    TERRA Operative Member

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    Just make doubly sure there are no leaks. You don't want your setup to siphon your tank dry and dump the water through your house....
     
  11. OP
    OP
    Oosh

    Oosh Member

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    Decided I'd do some testing, nothing like empirical evidence, I have a spare heater and a Eheim 1250 pump that's been collecting dust since I was going to get in to water cooling but never did.

    Last night I let 25L of water sit until the temp stabilised to 22.4C, then placed the heater and pump (to agitate the water and take in to account any extra heat it'll add in the second test) inside, I then checked the temp over the next hour.

    Once I've made my canister heater I'll do the same and compare results, I'll also run both tests longer to see how well both maintain a steady temp, my existing in-tank aquarium setup wanders by about 1C as is without causing issues.

    Will keep you posted, oh and as the for the siphon issue, it's something you already run the risk of running a canister filter. Reduced flow is a good point too, I'll compare performance with and without the canister heater when it gets to it.
     
  12. jebz

    jebz Member

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    As much fun the DIY path would be, I really wouldn't bother. Just pick up a 300W Jaeger heater (under $50), just the one single unit is capable of heating up a 1000L tank.
     
  13. OP
    OP
    Oosh

    Oosh Member

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    I've only seen Hydor inline heaters (got a link), but I already have two in-tank heaters, so I may as well use them plus this setup should be scalable (extra heaters in the canister).

    Also, even though my research (soon to be tested) suggests in-line heaters are more effective, I find it hard to believe 300W would be enough for 1000L given that an in-tank item would only be good for ~300L.
     
  14. Urban_Jungle

    Urban_Jungle Member

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    Good idea. I have lost a couple of heaters over the years due to my Oscars thinking they were fun to play with.

    I would just use the canister filter as the pump, ie cut the output hose on the filter and connect it up to the inlet and outlet of the outside heater.
     
  15. OP
    OP
    Oosh

    Oosh Member

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    Yeap, that's the plan when it hits the tank, but I will be testing the effects on flow.
     
  16. OP
    OP
    Oosh

    Oosh Member

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  17. jebz

    jebz Member

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    I don't know how it works, it just does. It's a normal in tank heater, recommended range between 600 to 1000L, and it ran in my custom 6' (800L) just fine.

    I picked up mine from Pet City, not sure if they have an online section but I'm sure numerous online stores would have them.

    More in depth info here.
     
  18. spedwards

    spedwards Member

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    Some heaters are not meant to be completely submersed in water...
     
  19. dawesius

    dawesius Member

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    just watch your DIY budget doesnt surpass the cost of an eheim with an inbuilt heater...
     
  20. OP
    OP
    Oosh

    Oosh Member

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    Yeah I'm aware of that danger. :)

    This idea is still on the table, but on hold until I get time to visit a proper plumbing supplies store, Bunnings alone just ain't gonna cut it.
     

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