Where Do You Place Your Thermometer?

[BreakingWave]

That's why I made it so you could pick multiple answers .

I can't ever see/answer the polls on Tapatalk :/

 

[mlb75]

The way I see it the only place the temp really matters is in the display which is why I place the thermometer I care about in the overflow. IMO the overflow is the most accurate indicator of DT temp because of the turnover rate through it directly from the display. You could put it in the display as well but it is more likely to be effected there by warm water from the return (assuming you have heaters in the sump) and then it's visible in the DT which I don't like. To me the best place for a heater is in the sump because the smaller body of water should be easier to heat (depending on flow) than the large display or the high turnover of the overflow. That way the heater will continue to heat the water in sump to be returned to the display until the overflow see's the temp its looking for. Just need to balance flow rates though the sump to keep the temps consistent, if the sump is several degrees higher then you might need to increase flow.

With the temp controller and heater being in different areas yes there are issues that could arise but if you lose power etc then the heater should end up off too preventing any kind of overheating issue. If you lose just the return pump that could cause an issue but as long as they're fed from the same power source that should be mitigated unless the pump failed but some risk is always accepted and I'm fine with that one.

 

[valsterb]

Temp probe in the first part of sump on a GHL Profilux controller. 2 Eheim 300W in the last part of sump with the return pump. Heaters are set at 80F on the heater, but the controller is set at 78F. That way, if the controller fails, the heaters fail safe at 80F. I also have the controller pulse the heaters so that they are never on too long. Never had a problem here in Canada!

 

[Newb73]

One high up in the display and one just after filter socks in sump.

Display always runs about 1 degree higher than sump.

One heater in overflow and an emergency heater in display.

 

[BigJohnny]

I have my most accurate temp controller probe in the tank itself. I also have a separate thermometer in the sump. I keep a 300 watt Eheim heater in the overflow and another 200 watt in the sump.

The sump temp is always a few degrees higher (about 4) than the tank. So I'm guessing that if your temp controller is based in the sump, that the tank is actually colder by a few degrees (unless the heaters are in the tank)

This poll doesn't apply to small AIO tanks.

My 90g DT/40g sump only have a .2F difference in temperature. Heaters are in 2nd section of sump, temp probe is in the 1st (drain). I think your heaters may be underpowered if you have that much of a difference.

 

[dazedandconfuzed]

Heater this is Florida....

 

[madweazl]

The way I see it the only place the temp really matters is in the display which is why I place the thermometer I care about in the overflow. IMO the overflow is the most accurate indicator of DT temp because of the turnover rate through it directly from the display. You could put it in the display as well but it is more likely to be effected there by warm water from the return (assuming you have heaters in the sump) and then it's visible in the DT which I don't like. To me the best place for a heater is in the sump because the smaller body of water should be easier to heat (depending on flow) than the large display or the high turnover of the overflow. That way the heater will continue to heat the water in sump to be returned to the display until the overflow see's the temp its looking for. Just need to balance flow rates though the sump to keep the temps consistent, if the sump is several degrees higher then you might need to increase flow.

With the temp controller and heater being in different areas yes there are issues that could arise but if you lose power etc then the heater should end up off too preventing any kind of overheating issue. If you lose just the return pump that could cause an issue but as long as they're fed from the same power source that should be mitigated unless the pump failed but some risk is always accepted and I'm fine with that one.

Do you see much difference? The temps in my setup run within .2° between the displays overflow and sumps return chamber when the heaters are on and identical when they're off.

 

[Bruce Burnett]

My thermometer is in overflow and I don't use a heater or a chiller so no controller.
When I used a controller I always put probe in the return section of sump near pump with heaters in same section. Always lots of flow through sump and never had much difference in temperature in sump vs tank. If your return pump stops working and you do not have a flow switch your heaters or chiller could continue to run if they are in different locations then your controller probe. If you have much temperature variations and using multiple probes or thermometers then either they are off from each other or not enough flow.

 

[Forsaken77]

My 90g DT/40g sump only have a .2F difference in temperature. Heaters are in 2nd section of sump, temp probe is in the 1st (drain). I think your heaters may be underpowered if you have that much of a difference.

I have 500 watts of Eheim Jagers in a 93 cube with another 30 gallons of water in the sump. Technically, just the 300 watt should do it. But my thermometer in the sump, not controller (in tank) is after the 2 heaters. But because some heated water lingers down there longer, it raises the sump temp.

 

[madweazl]

I run dual 250w heaters in my sump on a 75g display/30g (20g actual volume) sump (73-74g total volume).

Heaters are barely visible between the skimmer and the refugium chamber (mounted vertically). "Return" probe is mounted in the return chamber to the far right.

 

[Forsaken77]

Temp probe in the first part of sump on a GHL Profilux controller. 2 Eheim 300W in the last part of sump with the return pump. Heaters are set at 80F on the heater, but the controller is set at 78F. That way, if the controller fails, the heaters fail safe at 80F. I also have the controller pulse the heaters so that they are never on too long. Never had a problem here in Canada!

How do you "pulse" the heaters? Usually the controller turns them on when needed and off when temp is reached?

 

[srad750c]

I check my temp from inside tank using temp gun, same spot on rock each time. I use Eheim True Temp 250W

 

[Forsaken77]

I check my temp from inside tank using temp gun, same spot on rock each time. I use Eheim True Temp 250W

Just out of curiosity, have you double checked the gun against a thermometer to see if it's accurate? I've never seen someone use one of those for an aquarium before. They work through liquids?

 

[srad750c]

Just out of curiosity, have you double checked the gun against a thermometer to see if it's accurate? I've never seen someone use one of those for an aquarium before. They work through liquids?

I check known temp source, they are approx .2-.5 degree form control source. I broke my lab thermometer a long time ago. I also check temp of snail on glass and rock in tank for comparison. The gun type works through liquids, the other doesn't. I just use the small one on surface of glass to compare results.

 

[mlb75]

Does it going through the glass not matter? Do you get a different reading if coming in from the top?

 

[srad750c]

Temp reads same wether I read through just water or through water and glass. My tank glass is 0.5” thick. Look at location of laser dot on rock and other on snail on glass.

 

[valsterb]

How do you "pulse" the heaters? Usually the controller turns them on when needed and off when temp is reached?

The GHL Profilux controller lets me turn on my heaters for 2 minutes, rest 30 seconds, on for 2 minutes, etc.

 

[Nhjmc]

I have an AOI tank (Red Sea max 130d) my heater is after mini sump,skimmer chamber in the heater chamber which is before the return pump (s) chamber. I have temp probe in back mid lower bottom left of tank.

 

[92Miata]

If its a heater that has an internal thermostat that you can trust - put the probe in the tank.

If its a heater with no thermostat - the probe needs to be in the same compartment as the heater - otherwise you're asking for a boiling sump the first time you have a return pump issue.