heaters: vertically or horizontally

[Jeff]

Does it matter which way you place your heater in your aquarium? 

I like my heater vertically, as the cord is less in the tank, and is easier to cover up. However, I've heard different opinions about having it horizontally - possibly dispersing the heat more efficiently?

Also - if you do go horizontally: does it matter if it's at the top / middle / bottom of aquarium?

 

Edited April 14, 2022 by Jeff

[BF McUmber]

I'm just regurgitating things they have said on live streams. But they said that horizontal may be more consistent. In the vertical position the warm water may stay around the heater if you have stagnant water in a corner or something. The thermometer is at the top of the heater and so if you just locally heat up around the heater it could think it is at temp but is just because of the local  hot spot. 

A horizontal heater will be forced to interact with more water because of how it has to be placed. So it will be less likely to think it is up to temp due to a local hot spot. 

If you have good flow it will combat the hot spots.  And if you have a remote thermometer it will also help with short cycling the heater.  

I have mine at 45 degrees below my low water line in case i forget to turn it off in a water change. 

Edited April 14, 2022 by BF McUmber

[Scapexghost]

45° angle is ideal, since the temperature senser will not be directly above the heating element. The lower in the aquarium the heater is the better, since heat rises. That said, it doesn't matter too much as long as you have decent flow.

[JettsPapa]

I like to put mine low enough that I don't need to turn it off when doing water changes.

[lefty o]

in theory, an aquarium heater would do its best heating of the entire aquarium if it was at its lowest possible position, totally horizontal.

[Kathy F]

I prefer horizontal but, in some tanks, I have no choice but to go vertical due to lack of room.   I like horizontal because you don't have to worry about evaporation exposing the glass nor do you have to freak if you forget to turn off during a water change.  

 

[Hannah Parker]

I put mine super low and horizontal so they are still submerged during water changes! 

[Jeff]

On 4/14/2022 at 10:06 AM, JettsPapa said:

I like to put mine low enough that I don't need to turn it off when doing water changes.

Never thought about this. I'll have to do this going forward.

I always keep mine on during water changes. Not on purpose though. I always forget to unplug it....

I keep mine vertically. However, I'm in the planning stage of re-structuring my tank. Boiling my new driftwood, as I type this. I'm very now interested in keeping mine vertical at the bottom now.

With that said - how do you keep the cord taught, and straight up and down instead of having wavy lines in the cord when you have your heater horizontally? Do you use suction cups?

Edited April 14, 2022 by Jeff

[The Goatee]

I’ve done horizontal and 45 degree for any bar shaped units. The only ones that have been vertical are those brick-style ones that show the temperature.

The only other thing that may make me consider vertical was if the tank was a vertical dimension. A lot of the bars are too long for vertical orientation in my tanks.

[darkG]

I have the heater hidden in a separate space, vertical, with deliberate circulation. I agree that horizontal near the bottom makes the most sense, and I agree that if circulation is... at all, it'll be fine regardless.

[CT_]

I think I have a hot take on this so let me preface this with three things:

1) It probably doesn't really matter in the end.

2) It probably only makes a difference if the there isn't already sufficient flow over the heater. 

3) the rightest answer (IMO), is to put in under lots of flow and use an external temperature controller.

 

My hot take is this:

Vertical will lead to a more stable water temperature throughout most of the aquarium, at least with a bimetal type thermostat.  The reason is that the bimetal thermostats have a lot of hysteresis (ie they tend to have a large temp swing around their set point.  One of my first forum posts here was about that).  If the flow is low near the heater the heat will rise and warm the thermostat first causing it to shut off earlier than it would otherwise.  You still get the same temperature swing near the thermostat, but since its switching on/off faster the average temp in the rest of the aquarium will be more even.  If you mount horizontal that heat has to spread across the aquarium before toggling the thermostat making the same swing global to the aquarium.

[JettsPapa]

On 4/14/2022 at 2:10 PM, Jeff said:

. . . With that said - how do you keep the cord taught, and straight up and down instead of having wavy lines in the cord when you have your heater horizontally? Do you use suction cups?

I never gave it a thought.

[nabokovfan87]

On 4/14/2022 at 6:30 AM, BF McUmber said:

I'm just regurgitating things they have said on live streams. But they said that horizontal may be more consistent. In the vertical position the warm water may stay around the heater if you have stagnant water in a corner or something.

it's actually an interesting dilemma because of the fluid dynamics of the tank.

First I will say, read the manual and know it does have requirements for positioning. Especially the higher end ones.

 

The one above is likely talking about substrate, not the rotation. It doesn't give a minimum dimension, probably should.  Most HoBs will cycle the water from the top to the bottom of the tank in that direction, that is why horiz makes the most sense. I run mine at a 45 degree angle.

 

[nabokovfan87]

On 4/14/2022 at 4:44 PM, CT_ said:

Vertical will lead to a more stable water temperature throughout most of the aquarium, at least with a bimetal type thermostat.  The reason is that the bimetal thermostats have a lot of hysteresis (ie they tend to have a large temp swing around their set point.  One of my first forum posts here was about that).  If the flow is low near the heater the heat will rise and warm the thermostat first causing it to shut off earlier than it would otherwise.  You still get the same temperature swing near the thermostat, but since its switching on/off faster the average temp in the rest of the aquarium will be more even.  If you mount horizontal that heat has to spread across the aquarium before toggling the thermostat making the same swing global to the aquarium.

Totally makes sense. I still say 45 degrees might be the balance of both. Placement near the flow of the HoB is absolutely critical.

[Odd Duck]

I’ve run submersible heaters every which way and I’m just glad that heaters are nearly all submersible now instead of the old clamp on the rim, non-submersibles I started with.  I started fish keeping when none were submersible.

It doesn’t really seem to matter that much which way you run the heater as long as you make certain it stays submersed during water changes OR you make certain to unplug it during water changes.  Having adequate flow is important for overall health of the aquarium and nearly any filter will give you more than adequate flow in regard to heater function.  Filterless tanks are often also heaterless tanks (tech free setups), and need very careful selection of inhabitants, so we’ll leave that to a specialist tank only.

I run the heaters whichever way suits the tank and inhabitants and don’t worry about angle, other than to make sure it stays covered or gets unplugged during water changes.

[TonyVideo]

I go by the manufactures manual as there are different types. I prefer bottom horizontal for convection current flow however my Fluval says vertical only.  I am amazed that more incidents of shocked people don’t happen which shows the safety of the heaters. When I was a kid xx years ago there were metal rimmed tanks and when people started putting submersible heaters in them it was not uncommon to get a mild shock. May be why metal frame aquariums are a thing of the past. They sure did look nice however. My first heater was an under gravel heater. Worked good until it didn’t. 😀

[Hoi Polloi]

If the manufacturer of the heater states to position the heater vertically, why would I go against that?

[Odd Duck]

On 4/19/2022 at 8:13 AM, Hoi Polloi said:

If the manufacturer of the heater states to position the heater vertically, why would I go against that?

Always follow the manufacturer’s recommendation if they make one.  Most only specify to make certain it’s fully submersed and that it shouldn’t be in the substrate if it’s not an undergravel heater.

[Guppysnail]

On 4/19/2022 at 11:19 AM, Odd Duck said:

undergravel heater

They make these? 😍. A hidden heater that’s not inline. Whoa Nelly. Where do I find one and are they any good?  Will they work with UGF.

[Odd Duck]

On 4/19/2022 at 10:27 AM, Guppysnail said:

They make these? 😍. A hidden heater that’s not inline. Whoa Nelly. Where do I find one and are they any good?  Will they work with UGF.

I don’t know if any of the current ones are any good.  The old ones never seemed to last, were pricy, and were a real pain to replace if they went out (which was a regular thing).  I tried one way back when, but it failed fairly soon and shocked me, so I was done with it quick.

It’s odd that submersible heaters have come a long way as far as safety in not shocking people, but have definitely not improved as far as durability.  The heater function is the same but adhesive/sealant tech has leapt forward in quality.

Edited April 19, 2022 by Odd Duck
Typo. You’re not really helping, autocorrect.

[Guppysnail]

@Odd Duck ORD. Thanks. I’m not much for self electrocution, I’ll pass. Momentary pie dream.

[Torrey]

On 4/19/2022 at 9:27 AM, Guppysnail said:

They make these? 😍. A hidden heater that’s not inline. Whoa Nelly. Where do I find one and are they any good?  Will they work with UGF.

I had the best luck with using an extenal heater (designed for reptiles) which is how I knew about the pymeter to control the temperature🥰

Mine lasted 3 years on the bottom of the aquarium (under the aquarium) and improved the function of my UGF (whick i didn't know was possible). It was a big aquarium... and when the heater pad died I replaced with a regular submersible that lasted 2 years. When we drained the tank and moved, I was going to get another stick on the bottom reptile pad but the tank was broken in the move, so....