Getting to bottom of equipment possibly causing heating issues advise

[rmorris_14]

Hey guys, is there a good way to test whether or not certain equipment is causing water temp to heat above a desired temp without swapping it out?

My tank info:
Biocube 32 with lid and stock lighting
Not very close to window or door

Equipment. stock return pump
skimmer Coral life V2
neotherm pro heater with inkbird controller

I didn't have this issue so much during winter. Occasionally my temp would go above the desired range even after the inkbird kicked off the heater. I assumed this was due to the tank being close to a heating and air register and the heat my HVAC was putting out, was tipping the tank over the scales.
However, now that the weather is becoming more mild, I am having issues with the temp going to high. The heater hasn't kicked on during during the day for at least a couple of days. (Im unsure about at night) Ambient temp in the house has been around 72 to 76 degrees. Yesterday my tank got all the way up 80.6. Before it got any higher, I put some ice in a bag and set it near the return flow until it dropped back down to 78.8. This morning when I woke up, even with the lights off and the house being cooler, the tank temp was already 79 degrees. Before I left for work the tank temp was up to 79.4 . I did the ice again and got it to 78.8 before leaving for work.

Could this be caused by my return pump running hot or my skimmer? Is there a good way to test for this without trying to swap out the equipment?

Thanks for any insight.

 

[danny_corals]

Does the lid stay closed?

 

[rmorris_14]

Does the lid stay closed?

Always .....unless Im working on the tank.

 

[danny_corals]

Try cracking it open to let some heat from the lights out.

 

[rmorris_14]

Try cracking it open to let some heat from the lights out.

my first thought was the lights. However, it seems odd to me that it was still 79 degrees when I got up this morning and the lights had been off all night. When I was getting ready for work, only the blues were on and temp was climbing. I put my hand to the lights and they were actually quite cold and didn't seem like they were contributing to the rise in temp.