Why put the heater in the sump?

[aggrofish]

Always always always run a heater where it can never run dry. Return section and overflow are a dangerous game.

Why have a sump if you're going to put equipment in the display?

I run a temp probe in my sump and display and this will tell me if my return has possibly failed. All I'd have to is run home, drop a heater in the display and fix the return issue. This is also why I run 2 return pumps. Unlikely both fail at the same time.

This is a very, very good point. I has a JBJ 45 gallon AIO with the heater in the back chamber. I had an ATO pump fail and it ran dry. No heat and water got cold. Two nems and a couple hammers / torches never recovered from the swing.

 

[ZombieEngineer]

Why would my overflow run dry? The only way I can see that happening would be if my tank's glass broke.

If the overflow has a small area, the heater is close to the water surface and it doesn't have out of water protection, the heater could evaporate enough water from the overflow to run dry.

As long as this narrow situation is considered and planned for, heaters in an overflow chamber is perfectly safe.

 

[Brucealmighty]

In the experience I have over the years the most likely component to fail is your heater not your return pump and it should be a rule of thumb to keep a back up pump even if its a smaller one to remedy the situation, then the question is more how long will your tank survive without the return pump and heat, I was under the impression that the rock work would keep the temperature from falling too quickly another reason for more rocks in the aquarium and dense ones at that not the airy fairy stuff some heavier stuff to also keep anaerobic bacteria in too.

 

[stevolough]

If your return fails and you are gone heat is not your biggest issue , heaters always in sump.

3 power heads in display. Tank would be fine without sump. So heat would be the issue.

 

[stevolough]

If the overflow has a small area, the heater is close to the water surface and it doesn't have out of water protection, the heater could evaporate enough water from the overflow to run dry.

As long as this narrow situation is considered and planned for, heaters in an overflow chamber is perfectly safe.

I had a situation when I was doing maintenance on my sump. Heater was in overflow with the temp sensor for it in display. Had return pump shut off for a while so the water in overflow got pretty hot! So remember to unplug if water flow is going to be off for a while

 

[rtparty]

Why would my overflow run dry? The only way I can see that happening would be if my tank's glass broke.

Depends on the overflow setup. If a return pump fails, the overflow level drops. If someone has a low standpipe in their overflow, they just exposed their heater to air. This could be a major issue.

There is no benefit to running a heater in an overflow. It won't keep the display heated if a return pump fails. It is in an area where it can run dry. Putting it in the sump before the return section is best practice.

 

[ZombieEngineer]

I had a situation when I was doing maintenance on my sump. Heater was in overflow with the temp sensor for it in display. Had return pump shut off for a while so the water in overflow got pretty hot! So remember to unplug if water flow is going to be off for a while

Or even better use a controller for the heater like an inkbird or apex that is measuring the display and leave the temp sensor for the heater itself where the heater is actually located and set a couple degrees higher.

 

[RazorJaws]

So what I went with is two heaters. A primary in the sump, and a backup in the display. Both on inkbird controllers. The sensor for the primary in the sump, and the sensor for the backup in the display set to 0.5 degree (C) cooler. The backup won't kick on unless the return pump fails or the primary heater fails. I'm happy with the solution. It gives me peace of mind.

 

[Wasabiroot]

I figure as long as I have heat and flow from the powerheads, it wouldn't be catastrophic, right? Or am I missing something. The tank would survive without the skimmer and sock filtration. .

I prefer the sump. My reasoning is that I have enough wattage for my total water volume, not the display itself (my sump is about 10-15g) and if my return pump fails, oxygenation will drop in the tank, meaning I'll prefer less heat above.

If power is lost, the placement becomes irrelevant anyways, but to me you'd want heaters in an area with consistent directional flow. That's likely near your return or somewhere in your sump. And it doesn't distract from the DT if it's below.

Two heaters is the way to go. Gives you more time to replace if one fails, and theoretically extends the total on off cycles before failure.

 

[Randy Holmes-Farley Verified Community Expert]

I'll give an another reason to not put it in the display, and that relates to creatures that may attach to it when it is not heating, and get burned when it turns on.

Anemones for example, or even snails.