Heater Accuracy

[Jake]

How tight of a band does your heater keep your tank in the cooler months. My tank is 78-80.5 in the summer when the house AC is on 24/7 and a fan in the canapy is running. Now with it getting cooler, my swing is 77-81 with my heater running. What temp do you have your heater come on at and what temp does it shut off at? Also, is your heater submersible or hang on type.

[BigAl07]

Submersible heater here and it's on a AquaController that turns in ON at 76 and OFF at 77. Daily my tank ranges from 75.5 - 77.5

[Woodstock]

I use a controller for both my main reef display and on my hospital/QT. Both tanks stay within a .5 deg swing. Currently 77.0 - 77.5 for the winter months.
I use Jager and Stealth submersible heaters.

[Cal Native]

I have about a 2º swing 76º to 78º

[InLimbo87]

I wouldn't worry about a swing from 77-81 each day (unless of course you notice visible stress).

[mps9506]

Like mentioned above, get a controller like an AC jr, or Ranco temp controller. It will keep your heater working, also you aren't very likely to run into heater malfunctions. Pretty much every glass and titanium heater I've used in the past has had quite a bit of "play" in the temperature range. I purchased a Ranco temp controller a few years ago and you just plug your heater into the controller, set the controller temp, I set the heater temp for 80, so just in case the controller gets stuck on, the heater will shut off...

Also please don't use a hang on heater, they just aren't suited for marine tanks, and really I don't think they are suited for FW tanks either

[Jake]

OK good feedback. I should change to a submersible and use a controller.

The ranges listed above show typically less than 78 at the high end with tolerance of .5 to 2 degrees swing.
So, is the desired optimal mixed reef temperature 76-78?

Somehow I thought it I was shooting for 78-80 range. Sounds like it is OK to lower it down some. Also, what are acceptable tank temperatures assuming it stays relatively consistant in temp?

[InLimbo87]

I'd suggest reading thru this : Reef Central Online Community - Common Misconceptions In the Hobby

I think you'll find there are some really good arguments as to why you shouldn't sweat temperature stability and high temps (to an extent of course) in the aquarium. I know there are two sides to the argument, but I think this thread sheds good light onto the "common misconceptions" that are often recycled over and over in the hobby.

[mps9506]

4.) It's very important to keep temperatures stable.

This one pops up a lot on the forums. As you may have gathered from the above commentary, the temperature on your average reef isn't really stable at all. Temperatures can shift greatly with a simple shift of the tides or currents. There are also shifts between day and night that are close to 5 degrees on average.

Conclusion: Stop worrying about your daily swing in temperature from your lights heating the water. There's no need to go buy expensive chillers or controllers to always maintain the same temperature. In addition to being pretty natural the temperature swing may be good for your aquarium inhabitants and make them less likely to succumb should you have a more major temperature swing. In closed aquaria I wouldn't suggest testing the limits of this, but if your swings are under 5 degrees from day to night I wouldn't worry much.

In my experience this is pretty much true, I have found once I got my temps a bit more stable day to night my corals seemed to respond better, but this was actually because my temps were getting to high I think. I also try to keep the temps tighter so I have some room for error. If your tank temps are hovering around 81-82F all the time it wouldn't take much to see it spike to 85-86F one day and stress the corals and see some bleaching (less a concern with soft corals, but in my experience SPS are very prone to bleaching when the tank temps spike). I attempt to keep mine around 78 just to have room for error.
The biggest advantage of a controller is you don't have to worry about the heater getting stuck on or off and your tank getting too cold or hot.

[wonderloss]

I like to use a controller, but that is because I do not trust the thermostat on the heater. Also, being in Florida, my problems is usually temperatures getting too high. The controller lets me control a fan to keep the temperature down. I definitely worry about high temperature more than swings. Without the fan, I had trouble keeping my aquarium from getting above 81ºF.