High tank temperatures

[MarkW19]

We're currently in a bit of a hot spell in the UK, and as such my tank has been warmer than it has been.

My heater is set at 27°C, but what with my lights (and even when they're off!) and room temperature (although room temp. is a couple of degrees lower, my tank always seems to be higher, even with the lights off), it's been hovering around 28.4°C, which is higher than I'd like.

So, as a temporary measure, I've been taking the hood off, and turning off the lights (I don't have any corals or anything).

But, short of getting a Chiller, what else can I do to keep the level in my tank just that bit lower, with the lights on of course? Why is the level in my tank higher than room temperature, even when the lights and hood have been off all day? If I lower my tank temp. by about 1°, would that mean it would max out at 1° lower than it is now (ie. 27.4°), if the room temperature stays as it is now (it rarely gets hotter than this!)?

If I put a fan in there, surely it's not going to cool the hood/lights down, but just blow the already hot air about?

FYI, my tank is 35gallons, with 2 Maxijet powerheads, and external Eheim filter/heater.

Any help would be appreciated!

 

[darb2]

Un plug your heater. I once had a heater break in the on position and the temp in the tank went way high.
If that isn't the problem freeze a soda bottle of water and float it in the tank.

 

[MarkW19]

The heater is fine, the temp goes down after a while (albeit slowly).

I was thinking of a more permanent solution rather than floating bottles of water in the tank

Thanks for the help though

 

[darb2]

go topless?

 

[MarkW19]

Hehe...it helps a bit (like 0.2° lower), but its mainly the lights that are the problem.

But what I don't understand, is that even with top off/lights off, and temp starting at 27° in the morning, it raises to 28.4° in mid-afteroom, even when room temp gets no higher than 26° - what's driving the temp up that high (my heater is set at 27 and turns off when it gets to this temp - I've checked)...

 

[steve-s]

If you have a sump, place a larger floor fan so it is constantly blowing air across the sump. If no sump, a fan mounted securely beside the tank top so it blows air across the surface water should increase evap thereby cooling the tank. Also be sure there is not a glass lid on the tank.

If that fails, the 28.4° is a tad high but what I would suggest is increasing the heater setting to 28°C (82.4°F) which would mean much less swings in the temp throughout day and night. The higher temp is not near as damaging (stressful) to the aniamls as the yo-yoing temp. A 0.4°C (1°F) is much easier for the fish and corals to contend with.

Other than that, you'd need to look into a chiller.

Cheers
Steve

 

[MarkW19]

Cool, I'll try the fan idea.

What I don't understand though, is why the tank temperature is higher than room temperature, even when everything is turned off and the hood is off?

 

[darb2]

Then the heat must be coming from a ph or the canister. If all of your equip is running normal(no extra heat) then Try a fan and see what happens :?

 

[steve-s]

Then the heat must be coming from a ph or the canister.

It definately could be a filter pump or powerhead. Some models definately give off a fair amount of heat. Given the lower nightime temp, it likely the lights as Mark indicated or possibley direct sunlight(?).

its mainly the lights that are the problem. ........temp starting at 27° in the morning, it raises to 28.4° in mid-afteroom, even when room temp gets no higher than 26° - what's driving the temp up that high (my heater is set at 27 and turns off when it gets to this temp - I've checked)...

If the heater is set at 27° it will maintain the tank no cooler than that no matter how cold the room gets. If the temp returns to the 27° at night after lights off then the lights are generating more heat than the AC in the room can handle.

Does the light hood have fans built into it?

Cheers
Steve

 

[MarkW19]

No direct sunlight, and no fans.

I just dont understand why (with no lights or hood on all day, and AM temp at 27), the tank temp can get higher (28°) than room temp (26°)?

 

[Atari]

It is a bit hot here right now huh?

I'm sure it's something to do with your equipment because my room temp got over 29c today and the tank stayed around 27.5c. All I have is a floor standing fan in the room that blows over the top when it swings round. Lots of evaporation keeps it cool.

BTW, never rule out faulty meters/probes/test kits etc.

 

[steve-s]

No direct sunlight, and no fans.

No sunlights a plus. No fans in the hood isn't unless you meant external fans.

I just dont understand why (with no lights or hood on all day, and AM temp at 27), the tank temp can get higher (28°) than room temp (26°)?

I'm at a bit of a loss. With no lighting, no lid and the ambient room temp remaining constant, there's no reason. Do you have a wavemaker with a "night mode" that reduces the flow?

BTW, never rule out faulty meters/probes/test kits etc.

Excellent point

Cheers
Steve

 

[srgetz]

It should be closer to room temp, I'm guessing your thermometer is reading a bit high due to malfunction or misplacement. Have you tried the thermometer from a different position in the tank? Are just be measuring surface temp? This can be higher than bottom temp with lights on, try a lower postition. Alternatively, have you tried a different thermometer? I have a cheap one that always reads high....try a glass one that can go deep.

 

[MarkW19]

I'm now maintaining my tank temperature at between 27.7 and 28.4°C, which I guess is better than ranging from 26.4 - 28.4? Although it's still a little high for my liking.

When this strange hot period is over (it can't go on for that long, it's not like the UK!) I'll slowly drop back down to 26.4 - 27.2°C again, as it was before this hot spell.

Or should I just stay at 27.7 - 28.4 like I am now, to avoid most yearly fluctuations?

 

[Atari]

26-27 is definitely a better range.

 

[MarkW19]

It's hard to keep at 26-27 though.