Curious about temperature change in a tank...

[RussC]

In South MS we have about three and half days of fall during which time the temperature and weather can't make up their mind on what to do next. That means the brutal freezing unbearable miserable winter months are just around the corner :lmao:. If you ask me, I'm looking forward to summer! So that brings me to my question(s)...

What is a healthy temperature change in a tank? Right now my minimum is set to 75.5 and my cutoff is 78 degrees. I have a Finnex 800 watt heater. In hindsight, I have since learned (and agree) that it would be better to have two smaller heaters, neither of which could cook the tank if one was to fail in the on position (unlike my nuclear reactor I have now). So that will be one of those things that will change (learning curve). But for now, it takes no time for my 800 watt to take my tank from 75.5 to 78. It happens fast. That got me thinking. Is that change too fast? What is too fast? I like gradual. Because nothing good happens fast in this hobby! Ain't that right, McG?

With the muscle in this heater of mine, maybe I should decrease the difference? But that means more on and off operations. Never good for any equipment to do that. I've looked at other recommended paramethers and most all seem to fall around 76-83 degrees. What do you guys set yours for? And why? I have a mixed reef, or will have a mixed reef. And remember, most of the year in South MS is hot!

As always, your advice and input is appreciated.

Thoughts?

 

[billdogg]

It is not uncommon for a tank to go +/- a couple degrees daily. That is especially true with metal halides and to a lesser degree (pun intended) when using T5. IME. LED's have removed lighting from the temperature equation. Submersible pumps add and often significant amount of heat, but they are always on so that would just lessen the use of the heater(s).

My tanks stay pretty stable at 78 year around, but we are firm believers in the use of AC int he summer and the furnace in the winter to keep the house comfortable.

 

[hkgar]

Check this out for some guidelines. Note that the watts per gallon are for actual water volume, that means take into consideration rock and sand. Get two heaters, preferably each heater should have a temperature control so you have redundancy with two controllers.

I have 3 heaters in my 165 gallon system, each on a separate Apex plug. I use a virtual control outlet and set the swing from 78 to 78.5

Fallback OFF
If Tmp > 78.5 Then OFF
If Tmp < 78.0 Then ON

 

[RussC]

I totally get having multiple heaters instead of one monster. I missed the boat on the decision. Fortunately temp in my area of the country is only extreme in the summer and winter around here is just in the way. My house is very well insulated...see my post on PH.... I think I'm going to try the half degree difference and see how the that goes and just watch my tank to see how things react.

 

[mcgyvr]

As I just turned our heat in the home on yesterday I also threw a heater/controller back on the tank for winter..
I have my controller set to turn heater on at 77 and off at 78..
As stated by Billdogg a few degree increase with the lights vs off daily doesn't seem to cause any problems and there are always "cool/warm" currents in the ocean too making rapid localized temp changes..

I agree that bumping up your min slightly is a good idea but I doubt you will notice a difference with a 3 deg swing vs a 1/2 deg swing.. But less is better for no other reason than its just "more stable" and corals love stability..

 

[ROlympia]

I have a 3 degree swing. Nothing in my tank seems to mind. I forgot to turn the heater relay back on a couple of weeks ago after feeding and nobody seemed to care that the temperature was approaching 70 before I caught it the next morning.