heat fluctuation

[Tajjo]

What are some of effects heat fluctuation can influence on a tank?

[reefworm]

Depends on the degree of and perhaps, to some extent, the rapidity. Changes within a range of roughly 78~86 are normal, and according to Greenbean, movement within those numbers is actually desirable. I'm guessing that really rapid change, like maybe a drop of 8 or more degrees within a hour might have some potential for harm, but I'm not really sure of that either. My tank will go from 80 to 84.5 over the course of 2 to 3 days with no ill effects. Temps outside that range should be avoided. It can effect a number metabolic processes.

[Tajjo]

the reason I ask is because my corals are looking dull and browning out. All my perams are desirable. Ro/di. My temp is usually 70-73 in the morning by 5:00 it's 78-79 this is the only thing I can think of. 0 phos and 0 nitrate

[reefworm]

70-73 is pretty low. do you have a heater?

[reefworm]

some other questions:
what types of corals?
what are your readings for salinity [or specific gravity], alkalinity, calcium, pH and magnesium?
what test kits are you using?

[virginiadiver69]

Yeah...your low end is pretty low. I don't know if that's causing your specific problems but it's low none the less.

[crvz]

Way too low in my experience, why don't you heat the water to keep it in the upper 70s?

[blakeorme]

I spent the first year of the hobby on Wet Web media and those guys definitely frown on Temp fluctuations more than 2-3 degs. If you think about in terms of the ocean that is native to the animals there are definitely very few if any temp fluctuations.

[virginiadiver69]

Originally posted by blakeorme
If you think about in terms of the ocean that is native to the animals there are definitely very few if any temp fluctuations.

I think you may be misinformed. This is not the case at all. The temp fluctuates on a seasonal, daily and even intertidal basis.

[greenbean36191]

I spent the first year of the hobby on Wet Web media and those guys definitely frown on Temp fluctuations more than 2-3 degs. If you think about in terms of the ocean that is native to the animals there are definitely very few if any temp fluctuations.

Luckily corals don't subscribe to the advise from WWM and tolerate the large and frequent changes that occur on the reef quite well. In fact they benefit from them.

Tajjo, your temps are extremely cold for tropical reef organisms. Most of your range is well below the wintertime low temps seen on reefs and is very close to lethal limits for corals. On an average reef these animals don't see temperatures below ~76 at any point during the year. Many corals start bleaching or dying at temps just below 70.

[blakeorme]

One more and its a TKO... But I just may throw in the towel on this one. "marine bio/ reef ecology"
Greenbean, whats your avg temp and does it fluctuate day to night?

[Tajjo]

I had 2x 250 watt ebo jäger's. Then one just stopped working. For no reason. I think the temp reader is messed up. Since it turns on just no heat. gravity is .023, alk is 10, calcium is 400, nitrates 0, phos 0, I don't have a mag test, my ph is 8.0-8.1 withmy calcium reactor

[Tajjo]

I had 2x 250 watt ebo jäger's. Then one just stopped working. For no reason. I think the temp reader is messed up. Since it turns on just no heat. gravity is .023, alk is 10, calcium is 400, nitrates 0, phos 0, I don't have a mag test, my ph is 8.0-8.1 withmy calcium reactor tests as of this morning

[Tajjo]

API reef master test kit

[wrott]

blakeorme,
The reason greenbean36191 responded to your statement in the way that he did is because he has studied marine biology and ecosystems for many years. I believe he has recently received a Ph.D. in "marine bio/ reef ecology".
He has seen evidence that a fluctuation in temperature is beneficial to reef inhabitants, because it induces the production a variety of enzymes that regulate metabolism. A stable temperature of 76-78F does not allow for the "proper" enzymes to be produced fast enough to metabolize a coral that has suddenly been introduced to 80-84F water.
And I would say that greenbean is one of the most knowledgeable and respected persons when it comes to ID or most anything reef related.
Tajjo, yes, any temp below 75F in a tropical reef would be asking for trouble.

[blakeorme]

I realized that when I saw the occupation. No offense taken at all. Hence the throw in towel comment. The best part of this hobby is the wealth of knowledge that we can gain from such informed/educated people. Having realized that, I am interested (to learn) what the best temp range/swing is for a mixed reef. Do you have a link.

[virginiadiver69]

blakeorme, I used to be real anal about temp stability ( and several other reef related issues ). Especially when I got a controller, I had the ability to keep temp within a 1 deg swing. After a lot of reading and personal observation over two years with my experiment I've learned these things are a lot more resilient than we give them credit for. Other than common sense husbandry I follow a pretty laissez fair reef keeping method. Mine fluctuates from about 75 in the morn. to about 81 at lights out in the winter. Summer temps are a couple deg. higher but same 5-8 degree swing.

[blakeorme]

You just saved me some cash. Thanks. I just installed my Halides and the temp. swings from 80 at lights out to about 76 at lights on. I have a single 300watt heater that keeps it right at 76 w/ room temp at 72. PS. sorry for the highjack.

[greenbean36191]

Well just for the record, I don't have a PhD. I'm working on a masters but will probably transition to a PhD track before I get it.

When I had my own tanks they would range from 78-83 in the winter and about 80-86 in summer.

[thecoralreefer]

Greenbean is right.
You get temp fluxes everytime it rains,when the cluods go overhead, Currents from the depths coming up,a sorts of things changing all the time.
If you ever go diving you can feel them as you swim along.
Sometime I think "where did that come from" when I am down there.

[virginiadiver69]

Originally posted by blakeorme
I have a single 300watt heater that keeps it right at 76 w/ room temp at 72.

I like to run more than one heater for backup purposes. It a good idea to run them on a controller so if they go haywire your covered there also.

[greenbean36191]

Sometime I think "where did that come from" when I am down there.

A lot of it comes from hobbyists reading pop-sci or news articles that refer to reefs as stable or that say "changes in temperature of as little as 1-2 degrees can lead to mass bleaching" and taking those statements out of context. Some authors (like Calfo) base their recommendations on studies done in FW or temperate fish that didn't evolve in environments nearly as variable as reefs- although to their credit, this was about the best hard data we had on the subject until about the last 5 or so years.

[wrott]

greenbean36191,
I awarded you prematurely, I don't know why I thought you had graduated--maybe that move to the Red Sea threw me off.
blakeorme,
I'm sorry, I didn't mean to slam you just for asking a question.
Rodney

[blakeorme]

No worries, wrott.

[Tajjo]

I think I'm going to try a water change