Can LED Lights Increase Water Temperature?

[LuisJr80]

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?

 

[Ellery]

Yes, LED's still emit some level of heat and if your tank is totally enclosed then it will keep heat in. 78F is fine as long as it's slow gradual changes. My main system I'd rather keep at 76F but my Fluval EVO13.5 does get just as warm as yours even though I keep my house at 70F.

 

[Lavey29]

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.

 

[LuisJr80]

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.

So I try to keep my home during the day between 74-77 degrees and at night at 68-70 degrees.

No, the tank does not get any direct sunlight, even though its in the part of the living room where there is a glass doors that lead out to the patio in the backyard.

I currently have the LED lights on but have the the top cover opened up to see if that elevates the temp.

My current reading is 81.5 degrees and has been there for a while now.

 

[LuisJr80]

Yes, LED's still emit some level of heat and if your tank is totally enclosed then it will keep heat in. 78F is fine as long as it's slow gradual changes. My main system I'd rather keep at 76F but my Fluval EVO13.5 does get just as warm as yours even though I keep my house at 70F.

So how do you keep that temp down when it starts to creep up?

 

[wwarby]

I have the same problem with my Fluval Evo, and I’m 100% certain it’s the lights heating the tank. I have a cheap heater in there with a thermostat it dial but even if I turn it off my tank overheats with just the light and the ambient room temperature. It’s pretty annoying.

 

[Tamberav]

A fan blowing on the water or small chiller or if you have soft corals then 81/82 is not a problem. Likely not a problem for most corals.

I had a softy tank that was 84ish every summer as I didn’t have AC in the apartment. Everything looked great.

 

[Gtinnel]

So I try to keep my home during the day between 74-77 degrees and at night at 68-70 degrees.

That is probably the biggest reason the tank gets warmer during the day. The lights will add some heat but a 6-10 degree change in ambient temp will effect tank temps also.

 

[Spare time]

The lid is more of an issue than anything. The lights are very close to the water so some heat will be transferred to the water, but lids in general can result in this issue

 

[LuisJr80]

A fan blowing on the water or small chiller or if you have soft corals then 81/82 is not a problem. Likely not a problem for most corals.

I had a softy tank that was 84ish every summer as I didn’t have AC in the apartment. Everything looked great.

I actually have the lights still on but the top lifted off and it has dropped to 81.1 (0.3 degrees since I started this thread 42 mins ago)

I currently do not have any hard coral but I do plan on getting soft corals in the next week or so and an anemone for my Clownies. I plan o getting a bigger tank next year and that will have corals.

I know its harder to maintain a smaller tank vs a large tank due to water volume differentiation.

 

[LuisJr80]

Update: Now at 80.4 degrees with lights on but lid up with ambient temp in my house at 74-75 degrees. I wonder if I should just remove the lid and get myself some better lights with an elevated mount. I just saw this one in Amazon...Any thoughts? But now I have to deal with more evaporation. Pros and Cons for any changes.

SMATFARM LED Aquarium Light - Updated Program Coral Reef Light Dimmable 95Watts Full Spectrum Sunrise Sunset for Marine Fish Tanks Fish Tank Light with Timer Function​

 

[dcsorrell]

Update: Now at 80.4 degrees with lights on but lid up with ambient temp in my house at 74-75 degrees. I wonder if I should just remove the lid and get myself some better lights with an elevated mount. I just saw this one in Amazon...Any thoughts?

​

SMATFARM LED Aquarium Light - Updated Program Coral Reef Light Dimmable 95Watts Full Spectrum Sunrise Sunset for Marine Fish Tanks Fish Tank Light with Timer Function​

That's what I would do. The problem is that the lid holds in heat produced by the fixture, and led fixtures do produce some heat.

 

[kevgib67]

I have a 32g Biocube and temp stays at 78 degrees 24/7. I added two additional led strips and run both a uv and protein skimmer. I agree with Lavey29 and Gtinnel. I wouldn’t be surprised if your heater is running higher than what you have it set for and my house is running at 72 degrees 24/7.

 

[vetteguy53081]

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?

They can if too close to the water surface. Run a hobby fan across the tank which will disspate heat from the tank

 

[LuisJr80]

They can if too close to the water surface. Run a hobby fan across the tank which will disspate heat from the tank

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?

 

[LuisJr80]

I found this site that shows the top 10 Best Reef Aquarium Lights and I am looking into something that is affordable for a 16 gallon tank. I was looking at NICREW...Any suggestion would really help my decision?

Our 10 Best Reef Aquarium Lights in the US - April 2023 | BestProductsReviews.com

Easily compare & choose from the 10 best Reef Aquarium Lights for you. Don't buy a Reef Aquarium Lights in the US before reading our rankings | BestProductsReviews.com

www.bestproductsreviews.com

 

[Acros]

Yes. LED lights will increase tank temp (however, considerably lesser effect than t5 or mh lights).

Here is my temp map on a typical day when the house it kept at 73f. You can see that the temp increases when lights are on, and no heaters turned on during the photo period. I use one XR15 G5 and two 24” led bars over a 25g nano.

 

[Lavey29]

I don't know, while LED do put out a very minimal amount of heat, take a look at my fuge light in my sump below. By the logic of some posts in here my water in that section should be quite warm compared to the rest of the tank right? I keep my heater probe in that section to right below the light and I have no temp issues at all so I am not convinced that lights play any significant role in tank temp unless they are old style right at the water line on an enclosed tank.

 

[Smite]

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.

 

[Smite]

I don't know, while LED do put out a very minimal amount of heat, take a look at my fuge light in my sump below. By the logic of some posts in here my water in that section should be quite warm compared to the rest of the tank right? I keep my heater probe in that section to right below the light and I have no temp issues at all so I am not convinced that lights play any significant role in tank temp unless they are old style right at the water line on an enclosed tank.

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.