Maintain A Constant Temperature?

2 heaters heat the water to a preset temp. Lights come on and even though they're LED they are still enough to over the course of 8 hours raise the temp a couple more degrees. Putting glass lid on the tank is going to increase this effect.

It's freshwater community tank kept for the most part at around 78F.

I've got two 150W Aqueon Pro heaters that are plugged into a thermostat controller that supposedly has an accuracy of +/- .5 deg.
Between the controller, heaters, lights and lids the temp will fluctuate during a 24 hour period between 76.5 and 81.

Is this okay? I would think in nature it would be but I really don't know if tank raised fish need a truly constant temperature. When doing water changes I try to match the tank temp within a degree or so at the time I'm doing the change but these other changes, I don't know how to control or if I even should worry about it.

Thoughts? Thanks in advance!

 

You should be fine, especially if your tank is well circulated. You could do one of a few things:

1) Move your heater closer to the surface of the water (still 100% submerged tho), as the lights will warm up the surface water, and it will turn off your heater sooner. (Bottom of tank will be colder).

2) Ensure nice top water surface movement (either bubbler or just your normal filtration should be doing this). This will distribute the heat more evenly.

3) Move thermometer to lower part of the tank and see if temp is still as high as you measured it originally (should be pretty stable).

Overall, you shouldnt have to change really anything except for maybe location of the heater.

Hope this helps!

 

There's 2 heaters, as mentioned above. One at each end of the tank. The temp probe for the controller is located at the bottom of the tank pretty much in the middle so the temp being measured isn't the surface temp. There's a sponge filter as well as 2 airstones, all of this in addition to the Eheim canister that is the primary filtration. I'm pretty sure that the temperature I'm seeing is for the most part the temperature of the entire volume of water.

 

Most fish won't mind but it is quite a fluctuation.

 

Most fish won't mind but it is quite a fluctuation.

You've been in this hobby a while, right? Was this an issue with HO fluorescent or other high intensity lights? The temp management thing?

 

Never heard about such fluctuations during the day / night (with two heathers)

 

I put some of that silver bubble wrap insulation stuff between my aquariums and the walls. There are all kinds of cold/warm spots and drafts in houses that could affect your tank's heat.

 

my temperature fluctuates too. but I have a much smaller tank. the ambient air temperature of my house causes my fluctuations.

 

Ok but two heathers should cope with that.
They don't go out at night !!
Must be the heath from lighting.

 

Ok but two heathers should cope with that.
They don't go out at night !!
Must be the heath from lighting.

Some of the issue is related to ambient temp, I'm in Texas and the indoor temp is frequently around 79F. I don't even notice it unless I look at the thermometer. It's so much cooler than the outside temp that it seems cool.

The fish all seem fine, I was just curious. I may lower the set point of the controller and see what that does. There's a few variables at play here for sure.

 

I agree this is strange. Could you try this. Place a thermometer on top of the tank right under the lights. Leave it for an hour or so. What is that temperature?

 

Loose the Aqueons (I never had one that was worth an ounce of dirt) Go with Finnex HGP digitals with the remote adjust and temp sensor. I have switched all our aquariums to them. Best heaters I ever had in over 50 years in fish keeping.


And please no hate from the Aqueon fans. I only speak from my experience.

 

Loose the Aqueons (I never had one that was worth an ounce of dirt) Go with Finnex HGP digitals with the remote adjust and temp sensor. I have switched all our aquariums to them. Best heaters I ever had in over 50 years in fish keeping.


And please no hate from the Aqueon fans. I only speak from my experience.

No hate for Finnex, I'm just not replacing brand new heaters and a $100 digital controller. I'm pretty sure my issue is more related to Texas weather, ambient temps, glass covers and lighting. We had just hit the end of summer when I posted this thread (early October) and here it is the first of December and it was 80 degrees out yesterday. It plays heck with the heating and AC in the house and thus everything IN the house.