How many times per day - Temperature Swing

[Yellow Eyes]

I can only ever find this answer as "it's okay to let the temperature swing 2 degrees over the day" "5 degrees" etc etc.

I have an apex and can count how many times my heater comes on per day, how many peaks and valleys there are. So how many swings per day is safe for corals?

Currently it takes my tank about 1.5 hours to heat up, and then 2.5 to cool back down. I am running a 2 degree swing (a lot of research turns up 2 degrees is fine, maybe even better then "constant") 76.5-78.5 degrees. This totals to between 4-6 peaks per day (some of the cool downs are closer to 3-4 hours depending on house temperature)

 

[kurt_n]

6

No, but seriously... you're not going to find an answer to that question. I can tell you that in my tank, 10 swings between 79.4 and 78.4 is fine. That's what it did over the last 24 hours.

I think what's more important is how much the temperature swings. If you only have 2 swings, but they're 10 degrees, that's very different than 2 swings at 2 degrees.

I agree, I've read some stuff that leads you to believe that a 2-3 degree swing might be beneficial, but most of us just stick to what works. For me, that's a +/- 0.5 range for the most part. A little more during the summer.

 

[Pife]

I have 2 degree swings all day long its just fine.

 

[Yellow Eyes]

Yeah, I guess my question was more of a "what does everyone else do?" kind of question. I just wasn't sure if having 6 swings a day could be harming corals/fish or if it would be better to have less swings per day by increasing the overall temperature swing.

 

[SVTour]

Because my fish room is a converted porch to the house - I probably have higher temp swings than most folks. Typically, I try to maintain 78°, but being that the room does not have similar ventilation as the house, I need to run a separate AC in the summer, and heater in the winter.

During season changes (namely spring and fall) - it's tough to maintain, as we may have a 40° to a 80° day swing - which really changes the temps in the room - thus affecting the tank.

As seen in this, we had a relatively cold day on the 2nd - followed by a mild day on the 5th. My thoughts, the ocean changes temps often enough, I can't see this being an issue.

My tank is primarily SPS/LPS - and I've had no issues.

 

[gone fishin]

I personally do not think you have anything to worry about.

 

[dkeller_nc]

As others have noted, the important part isn't how many temperature swings a day occur, but the magnitude of those temp swings.

Generally, 2 degrees Fahrenheit is no big deal, and is about the range of a heater that's controlled with its own internal thermostat. However, many of us that have an Apex take advantage of the precise control that it affords, and set the on/off range to much less than this - in my case, +/- 0.2 degrees Fahrenheit.

It's true that for most electrical devices like heaters, on/off cycles wear out the components, so fewer cycles are better. Having said that, most quality heaters will last for many thousands of cycles, and they're inexpensive, so in my case I simply prefer to sacrifice heater lifetime in favor of a temp stability that's closer to a natural (tropical reef) system.