Can LED Lights Increase Water Temperature?

Lavey29 · Sep 29, 2022

Smite said:
The section still has flow going through it, so no it will not be warmer than the rest of the tank. You're still monitoring your whole tank temp. Including the water in the display making contact with room temperature air.

And DT have no flow or water exchange through filtration? The flow in the sump is much less then the DT right?

vetteguy53081 · Sep 29, 2022

LuisJr80 said:
Normally how high should the light be from the surface of the water to not affect temp but still give the right amount of light?

10-12"

LuisJr80 · Sep 29, 2022

Smite said:
Yes LEDs still create heat. If you place your hand a few inches below the fixture you'll feel heat, so will also transfer to the water. The issue is your lack of air flow with the biocube lid as you figured out. Now just keep an eye on your evaporation as that will increase. Potentially quickly in a smaller tank. Not an issue if you are running at ATO.

Which nano ATO do you recommend?

Smite · Sep 29, 2022

Lavey29 said:
And DT have no flow or water exchange through filtration? The flow in the sump is much less then the DT right?

Yes they do, which is why a heat source of any kind and anywhere in the system will heat the whole system not one section of it alone. That's why I pointed out your sump has flow and can't be used to prove that LEDs do not add heat to water.

I added an LED grow light when I set up a refugium at the beginning of this week. My low is 77.7f and my high is usually 80F. I have a fan on the display to cool the system. Since adding the grow light it takes the whole chaeto photoperiod to reach the low temp mark, around 6 am. I noticed because I heard the fan run all night which was odd. I have a acrylic cover for the fuge section which doesn't help but also had a bow in it come morning from heat absorbed from the LED grow light. It does drop but not like it did prior to adding the light. The wattage is higher and it's passively cooled which may contribute.

My radion G5 xr30s added a few degrees difference during the day when I ran LED on my previous tank, rimless. It took 2 CPU fans blow across the display surface to keep the system within 2-3 degrees. This was in a climate controlled house 70-72 degrees. Systems controlled by Apex.

I don't think there is even a debate on whether heat from LEDs do transfer to the tank water. A watt is energy and energys gonna have heat. It all depends on the wattage and supplied airflow. OP has an issue because he has an enclosed system, trapping the heat from his LED hood and equipment against his water.

Smite · Sep 29, 2022

LuisJr80 said:
Which nano ATO do you recommend?

I'm a huge fan of Tunze but they can be pricey. I'm not up to date on ATO systems because I've gravity fed my systems for the last 6-7 years. That's hard to do in a nano though.

If a ATO system has a sensor I'd want it to have a mechanic switch or other form of secondary backup to prevent failure/over filling. You'll place it in your return section.

Lavey29 · Sep 29, 2022

Smite said:
Yes they do, which is why a heat source of any kind and anywhere in the system will heat the whole system not one section of it alone. That's why I pointed out your sump has flow and can't be used to prove that LEDs do not add heat to water.

I added an LED grow light when I set up a refugium at the beginning of this week. My low is 77.7f and my high is usually 80F. I have a fan on the display to cool the system. Since adding the grow light it takes the whole chaeto photoperiod to reach the low temp mark, around 6 am. I noticed because I heard the fan run all night which was odd. I have a acrylic cover for the fuge section which doesn't help but also had a bow in it come morning from heat absorbed from the LED grow light. It does drop but not like it did prior to adding the light. The wattage is higher and it's passively cooled which may contribute.

My radion G5 xr30s added a few degrees difference during the day when I ran LED on my previous tank, rimless. It took 2 CPU fans blow across the display surface to keep the system within 2-3 degrees. This was in a climate controlled house 70-72 degrees. Systems controlled by Apex.

I don't think there is even a debate on whether heat from LEDs do transfer to the tank water. A watt is energy and energys gonna have heat. It all depends on the wattage and supplied airflow. OP has an issue because he has an enclosed system, trapping the heat from his LED hood and equipment against his water.

I run radion lights also. My tank goes 77 to 77.2 all day and all night consistently. You're right there is no debate on led lights their impact on tank temp if mounted properly is negligible. Now lots of other factors play a role like humidity, window light, house temp, heater quality, glass lid, etc... but lights are not a direct factor in tank temp changes.

Lavey29 · Sep 29, 2022

Smite said:
Yes they do, which is why a heat source of any kind and anywhere in the system will heat the whole system not one section of it alone. That's why I pointed out your sump has flow and can't be used to prove that LEDs do not add heat to water.

I added an LED grow light when I set up a refugium at the beginning of this week. My low is 77.7f and my high is usually 80F. I have a fan on the display to cool the system. Since adding the grow light it takes the whole chaeto photoperiod to reach the low temp mark, around 6 am. I noticed because I heard the fan run all night which was odd. I have a acrylic cover for the fuge section which doesn't help but also had a bow in it come morning from heat absorbed from the LED grow light. It does drop but not like it did prior to adding the light. The wattage is higher and it's passively cooled which may contribute.

My radion G5 xr30s added a few degrees difference during the day when I ran LED on my previous tank, rimless. It took 2 CPU fans blow across the display surface to keep the system within 2-3 degrees. This was in a climate controlled house 70-72 degrees. Systems controlled by Apex.

I don't think there is even a debate on whether heat from LEDs do transfer to the tank water. A watt is energy and energys gonna have heat. It all depends on the wattage and supplied airflow. OP has an issue because he has an enclosed system, trapping the heat from his LED hood and equipment against his water.

Additionally you contradicted yourself by stating the flow in my sump fuge negates the affect of my 12 hour light on it because you state your fuge which also has flow is the source of your temp variations.

Smite · Sep 29, 2022

Lavey29 said:
I run radion lights also. My tank goes 77 to 77.2 all day and all night consistently. Your right there is no debate on led lights their impact on tank temp if mounted properly is negligible. Now lots of other factors play a role like humidity, window light, house temp, heater quality, glass lid, etc... but lights are not a direct factor in tank temp changes.

We will agree to disagree there I guess as. I feel mine were mounted properly, in a climate controlled house, a rimless peninsula in the center of my living room, eheim jager heaters controlled by apex? Dead of winter, fans would still kick on. I had ventilation fans cut into my stand as well to remove equipment hot air. Still temps would increase alongside my photoperiod. But, maybe not for some.

At what wattage/per gallon is the question maybe. My system was acropora dominant, so I was running multiple fixtures and maybe at a high wattage than you are? But I'd argue they are a factor for most. I'm not saying added heat is a bad thing. If your lights are running so cool that they add no heat, then the heater wattage should factor into your overall lighting wattage costs which would diminish their wattage savings?

Smite · Sep 29, 2022

Lavey29 said:
Additionally you contradicted yourself by stating the flow in my sump fuge negates the affect of my 12 hour light on it because you state your fuge which also has flow is the source of your temp variations.

No I told you your sump has flow? SO stating that that section would be hotter than the rest was an incorrect assumption.

Lavey29 · Sep 29, 2022

Smite said:
No I told you your sump has flow? SO stating that that section would be hotter than the rest was an incorrect assumption.

But I never specifically said that section was hotter because it isn't. That's where my temp probe is and I was pointing out that the temp never changes there even with the light on. You said that is due to flow and then you said your fuge is the source of your temp variations due to the light and cover yet of course you have flow like me.

Just a friendly debate with differing conclusions. Appreciate your input.

Smite · Sep 29, 2022

I see, your overall temp never changes. I read that as that section doesn't get warmer.

No issue with a little debate here

I just wanted to make it clear to the OP that LEDs can indeed increase water temperature since that was his question.

Happy Reefin'

Lavey29 · Sep 29, 2022

Smite said:
I see, your overall temp never changes. I read that as that section doesn't get warmer.

No issue with a little debate here
I just wanted to make it clear to the OP that LEDs can indeed increase water temperature since that was his question.

Happy Reefin'

I think it's more related to his glass cover retaining heat though but I'm a big fan of the Helio heating elements and controller for maintaining my temp so well.

LuisJr80 · Sep 29, 2022

I went with the NICREW 30w LED and I get it tomorrow. The temp all day today has maintained 79-80.5 degrees, which is good for me (last few days it got to 82-83 degrees).

I have another question...Does the day light (white light) give off more heat than the moon light (blue light) or is it the same?

Smite · Sep 30, 2022

I don't believe the color effects the temperature at all. Most modern LEDs have more blue variations in the fixture than whites/green/reds so in that case it might create a little more heat. With the light you're going with, low wattage and dimmable over an open bio cube I don't think you'll have an issue with heat going forward. Your hood was trapping all the heat being produced. If you do still experience a heat issue then a simple fan blowing towards the tank will handle it. Just be sure to mind your top off if ditching the hood and even more so if adding a fan. Both those will increase your daily evaporation.

LuisJr80 · Oct 1, 2022

Hey all,

I went to my local shop and one of the guys that work there told me that I shouldn’t get a bubble tip anemone for my clownfish and a torch coral is I don’t have good lighting. He told me that I need to have a PAR of at least 200 if not they would die. Is that the case?
I see that the NICREW 30w I ordered, which I ended up canceling, only provides up to 60 PAR. What brand so you guys recommend for my 16 gallon?

Lavey29 · Oct 1, 2022

LuisJr80 said:
Hey all,

I went to my local shop and one of the guys that work there told me that I shouldn’t get a bubble tip anemone for my clownfish and a torch coral is I don’t have good lighting. He told me that I need to have a PAR of at least 200 if not they would die. Is that the case?
I see that the NICREW 30w I ordered, which I ended up canceling, only provides up to 60 PAR. What brand so you guys recommend for my 16 gallon?

Kessil has a nice small footprint for a nano tank.

3nanos · Feb 11, 2023

LuisJr80 said:
Hi all,

I have a 16 gallon BioCube and finding it hard to keep my temp ranger between 77-82, as I have two clownfish, a cleaner shrimp, some trochus snails and a sand shifting starfish.

I noticed this morning the tank starts out at about 79 degrees than the moment the LED lights go on, I start to see temps rise to 81 degrees. I have a heater and its set to 76 degrees.

Does LED light cause temp in increase?

How can I keep my temp at a constant 78-79 degrees?

Do you think that the heater set to 76 degrees might be too much for a 16 gallon tank? Maybe it needs to be set to a lower temp?

I have two biorbs, both with led lights. The lights are attached to the lids and both lids get very warm. I don't understand why these two led lights are the only leds I've ever experienced that got warm. This should not happen because leds DON'T get warm. It's one of the best things about led lights. It definitely has left me very concerned!!!

zeusyqiluvu2023 · Oct 1, 2023

Lavey29 said:
I doubt the lights have any affect on this. Does your ambient temperature in your house fluctuate? Does the tank receive sunlight? You need a new accurate heater. There are reefers that run light set ups with the power of the sun but their tanks don't heat up.

I disagree with you. When I turn lights off, the temp hangs around 80. I turn them on daylight setting, the temp rises to 85 in about 2 hours.
I have to keep day light off. I use the moonlight settings overnight. As soon as the night settings go on or if I might use daylights is when I see my crab! Lol! I'd like to know if there's a way to remove some of the led lights? Anyone? I ordered the fan, but changed my mind. Biocube says the 2 sides on the top are cooling fans. I don't see any such things on my Biocube. Just bought my aquarium in June 2023. Please reply if you know anything about my questions or concerns.
Thanks! DebRich

Lavey29 · Oct 1, 2023

zeusyqiluvu2023 said:
I disagree with you. When I turn lights off, the temp hangs around 80. I turn them on daylight setting, the temp rises to 85 in about 2 hours.
I have to keep day light off. I use the moonlight settings overnight. As soon as the night settings go on or if I might use daylights is when I see my crab! Lol! I'd like to know if there's a way to remove some of the led lights? Anyone? I ordered the fan, but changed my mind. Biocube says the 2 sides on the top are cooling fans. I don't see any such things on my Biocube. Just bought my aquarium in June 2023. Please reply if you know anything about my questions or concerns.
Thanks! DebRich

An old thread but it's ok to disagree. My radion lights run at 100% intensity 8 inches above the water for 10 hours and has no effect on my tank temp. Take a look at my fuge light running for 12 hours overnight right on the water surface and my temp probe is in the fuge also and still the LED light has no noticeable effect on my tank temp.

Also you should not have your moonlight running overnight. Fish need darkness to rest and sleep so moonlight should be off after a few hours and overnight.