Temp Swings

[soulsigma]

I can't get a steady temp on my mixed reef, the temp reads from a day time high of 79 to a night time low of 77 I've read that temp swings are good for reef tanks but I can't hold 77 degrees steady.

[chuckreef]

A two degree differnce should be OK. I've seen tanks with bigger differences with no apparent problems.

[soulsigma]

A two degree differnce should be OK. I've seen tanks with bigger differences with no apparent problems.

OK thanks I was under the impression that it had to remain constant at a certain degree at all times.

[bertoni]

The change isn't that bad, although 77 F is a bit low for a reef. I probably wouldn't worry much.

[rodney757]

If you raise you heater to 79 then you shouldn't get a swing.

[soulsigma]

The change isn't that bad, although 77 F is a bit low for a reef. I probably wouldn't worry much.

I've read that 76 to79 is a good range for a reef, so what your saying is that it should be above 77 and not at or below?

[soulsigma]

If you raise you heater to 79 then you shouldn't get a swing.

I understand what you're saying but I don't use a heater because I fear that keeping it @ 79 would be fine until my lighting system comes on and raises it into to 80 degree range.

[bertoni]

I targeted 82 F as the base temperature. That's a reasonable guess as to the average temperature of a reef. There's a lot of reading available, if you want some pointers.

[HighlandReefer]

Coral Reef Bleaching
http://www.marinebiology.org/coralbleaching.htm

by Jason Buchheim
Director, Odyssey Expeditions



From it:

Ecological causes of coral bleaching

As coral reef bleaching is a general response to stress, it can be induced by a variety of factors, alone or in combination. It is therefore difficult to unequivocally identify the causes for bleaching events. The following stressors have been implicated in coral reef bleaching events.

Temperature

Coral species live within a relatively narrow temperature margin, and anomalously low and high sea temperatures can induce coral bleaching. Bleaching events occur during sudden temperature drops accompanying intense upwelling episodes, (-3 degrees C to –5 degrees C for 5-10 days), seasonal cold-air outbreaks. Bleaching is much more frequently reported from elevated se water temperature. A small positive anomaly of 1-2 degrees C for 5-10 weeks during the summer season will usually induce bleaching.
=========================

Temperatures above 86 degrees F. will cause problems for coral. ;)

[HighlandReefer]

FWIW, the pCO2 level does complicate the temperature effect on coral regarding higher temperatures and coral bleaching, with higher pCO2 levels increasing the temperature effect on coral bleaching. Many of our tanks have a higher pCO2 level than found in the ocean due to high levels of CO2 in our homes. Higher alk levels in our tank water may tend to counteract this effect. It would be interesting to see a study completed regarding temperature effects on our coral in reef tanks with different pCO2 and alk levels. ;)

[rodney757]

I understand what you're saying but I don't use a heater because I fear that keeping it @ 79 would be fine until my lighting system comes on and raises it into to 80 degree range.

That's what I thought but it didn't happen and my temps are much more stable.

[jeff@zina.com]

I understand what you're saying but I don't use a heater because I fear that keeping it @ 79 would be fine until my lighting system comes on and raises it into to 80 degree range.

So, you don't use a heater and you're amazed that the temperature changes by a few degrees? What did you think was going to hold the temperature rock steady?

Your lighting doesn't add to the heater temperature. If the lighting takes it to 80F, the heater is still only going to heat it to 79F and stop there. In other words, the heater is a minimum temperature and that's it. Anything above that temperature has nothing to do with the heater.

Jeff

[soulsigma]

That's what I thought but it didn't happen and my temps are much more stable.

So if I use a good quality heater ans set it @ 79 it will keep the tempt @ 79 and once the PC followed by the MH comes on my temp won't climb because the heater will turn off and the lighting will keep it @ 79 until it completes it's 12hrs cycle and once the water begins to cool the heater will kick on to keep it at 79 correct?

[kgross]

The lights can cause the temp to go higher, but it is hard to say what it will do. Currently your lights are adding 2 degrees from what you say, putting your heater at 79, might make it go up to 81 (same 2 degrees), but it might only raise it to 80. As the temp is higher the tank will evaporate more, so it will take more heat to heat it up....

But I will say get a heater, and raise the total tank temp if need be, 80-82 is not a problem, but try to keep your swing under 2 degrees if possible.

Kim