Fluval Flex 32.5G light producing heat

proace360

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Hey all, I'm new to the hobby and recently (two months or so ago) started a tank with just 2 clownfish so far. Until this past week I haven't attempted to turn on the light with the aquarium as I was told to wait a bit to avoid an ugly phase, but I wanted to test out the stock lights that came with the tank. Normally my tank temperature rests around 78F with a heater and is stable unlit. I've noticed when I turn on the light to the default day/night cycle in the Fluval app, my temperatures gradually increase over a day or two to over 80F. This has happened three times now since I've been turning off the lights at this point out of caution.

I was under the impression that LED lights shouldn't be producing much heat and haven't heard of anyone else having this problem. Any ideas how to fix this issue (if it even is one)?
 

glb

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Hey all, I'm new to the hobby and recently (two months or so ago) started a tank with just 2 clownfish so far. Until this past week I haven't attempted to turn on the light with the aquarium as I was told to wait a bit to avoid an ugly phase, but I wanted to test out the stock lights that came with the tank. Normally my tank temperature rests around 78F with a heater and is stable unlit. I've noticed when I turn on the light to the default day/night cycle in the Fluval app, my temperatures gradually increase over a day or two to over 80F. This has happened three times now since I've been turning off the lights at this point out of caution.

I was under the impression that LED lights shouldn't be producing much heat and haven't heard of anyone else having this problem. Any ideas how to fix this issue (if it even is one)?
As far as the ugly phase, there’s really no way to avoid it. I had my tank up for a year before I bought lights and when I added them, I had several months of the uglies, even though the tank was established. How high did the temp actually get? 80-ish isn’t necessarily a problem, but higher temps do mean less oxygen in the water. The only time I’ve seen led’s heat up the water is when they are in an enclosed tank lid. You could also add a fan somewhere to blow across the surface of the water if you want to cool things off a bit.
 

Tathamet

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Agreed. It’s because the light is enclosed. The leds do produce less heat but it builds up if there’s nowhere for it to go. I took my lid off mine (9g flex). so I could use a prime hd but if I were still using the lid I would probably modify my lid by cutting out a small section and adding a pc fan into it. Hooked up with my inkbird for heating and cooling.

edit: I still do use the pc fan without the lid btw.
 
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proace360

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As far as the ugly phase, there’s really no way to avoid it. I had my tank up for a year before I bought lights and when I added them, I had several months of the uglies, even though the tank was established. How high did the temp actually get? 80-ish isn’t necessarily a problem, but higher temps do mean less oxygen in the water. The only time I’ve seen led’s heat up the water is when they are in an enclosed tank lid. You could also add a fan somewhere to blow across the surface of the water if you want to cool things off a bit.
My main concern isn't really the max temperature itself since I could adjust the heater I'm using but mostly how much the temperature fluctuates throughout the day. I don't want to harm the fish/coral eventually by having temperature swings... but are they able to handle temperature swings of a few degrees throughout the day?
 

AydenLincoln

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As far as the ugly phase, there’s really no way to avoid it. I had my tank up for a year before I bought lights and when I added them, I had several months of the uglies, even though the tank was established. How high did the temp actually get? 80-ish isn’t necessarily a problem, but higher temps do mean less oxygen in the water. The only time I’ve seen led’s heat up the water is when they are in an enclosed tank lid. You could also add a fan somewhere to blow across the surface of the water if you want to cool things off a bit.
Yes this ^
 

AydenLincoln

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Get a better light such as AI Prime don’t use the stock light especially if you want to grow coral like LPS/SPS. And remove the lid or get a little cooling fan. Clownfish are very hardy fish and can handle a lot but that doesn’t mean they are happy.
 

AydenLincoln

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My main concern isn't really the max temperature itself since I could adjust the heater I'm using but mostly how much the temperature fluctuates throughout the day. I don't want to harm the fish/coral eventually by having temperature swings... but are they able to handle temperature swings of a few degrees throughout the day?
Yes but you want to keep it minimal think like 1-2 degrees in fluctuation over 24 hours being the best and what mine is now. Most people’s tank on a good day without extreme heat or cold will fluctuate a few degrees.
 
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glb

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My main concern isn't really the max temperature itself since I could adjust the heater I'm using but mostly how much the temperature fluctuates throughout the day. I don't want to harm the fish/coral eventually by having temperature swings... but are they able to handle temperature swings of a few degrees throughout the day?
Yes, between 1-2 degrees is ok. Sudden temp changes are more of a problem then a gradual up and down every day.
 
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