Temperature fluctuations ideal?

[Starvin Marvin]

Hey,

For about 6 months I have been running an Apex Fusion with some 300w Finnex heaters on my 100g system.

I have tried both simultaneously, as well as singly with different set points.

I always get a temp fluctuation as shown in the screenshot.

I can manipulate this as needed with different set points and timing, but I'm not sure if I should be trying to improve on this?

What is considered "ideal"?

I just installed pH yesterday so that can be disregarded.

Thanks!

http://images.tapatalk-cdn.com/15/12/06/e4e65432051d6eee3d25205c2170f5dd.jpg

EDIT:
Also here are my Amps. Again, I moved a circulation pump off the Apex powerbar yesterday so that's why the pattern changed. Aside from that it's always a consistent up/down with plateaus.

http://images.tapatalk-cdn.com/15/12/06/db5eddc7ed55b078d9db227ed73578ec.jpg

[bertoni]

That's a very narrow range, and I'd just leave well enough alone, personally.

[MrsReefK]

That's a very narrow range, and I'd just leave well enough alone, personally.


My opinion is the same. Less than 1 degree change, I would leave as is.

[twon8]

IMO fluctuations of +/-5 degrees F are not a problem as long as the reef is accustomed to them. My 300 is regularly between 73-78

[disc1]

Worrying about less than a degree of temperature change?

[NSimpkins]

+1. If those rare your issues you're in really good shape.

What is your program for the heaters? What temp is your heater set to? Which do you want controlling what? Meaning do you want Apex to control or your heater to control itself with Apex as fall back? Most let Apex control.

[dkeller_nc]

As others noted, "ideal" is somewhat subjective, and one degree Fahrenheit is not going to be harmful to your tank's inhabitants.

As to why the fluctuation is always the same regardless of your heater configuration, I suspect that you may be using the Apex default heater program that has a default dead band (i.e., the temperature difference between heater "on" and heater "off").

It is possible to control this much more tightly with an Apex if you program the on/off setpoints on the heater outlet in "advanced" mode through the web browser interface (not Apex Fusion). In my case, my tank varies by 0.2 degrees Fahrenheit over the course of an hour or so.

[Starvin Marvin]

Hey guys, thank you for chiming in.

I was actually more worried that I had too narrow of a temp band. I don't know if longer more gradual swings would be better.

As mentioned, it's definitely possible to fine-tune a sweeping temp curve, say 3 degrees cooler during the night and back up to temp with the fake sunrise.

But is it ideal.. Is it beneficial, doesn't sound like it would be in your experience.

It's a good point too about how as long as the tank is accustomed to something, it can become the new normal.

Here is my programming if you guys want to see it.

Thanks again,
Marvin

http://images.tapatalk-cdn.com/15/12/06/1f073a416afaec9cf9c4492d573ada05.jpg

[Member No. 1]

Marvin...
Does your heater has it's own thermostat? If so then you want FALLBACK ON
and the temp on the heater set 2* higher than your Apex setting.
Reason being, if the EB8 were to loose communications, your heater would still work and it's own thermostat would take over control. The way you have it programed, if communication was lost, would wouldn't have any heat.
Here is my program. I have 2 temp probes, one in tank, one in sump.
I also run a chiller.

Fallback ON
If Temp_T < 78.1 Then ON
If Temp_T > 78.3 Then OFF
If Temp_T < 70.0 Then OFF
If Temp_S > 78.6 Then OFF

Question, what is the purpose of your Min Time statement?

[C.Eymann]

IMO fluctuations of +/-5 degrees F are not a problem as long as the reef is accustomed to them. My 300 is regularly between 73-78

Whoa 73??? Seriously? Sounds awfully chilly for a reef aquarium.

[twon8]

Whoa 73??? Seriously? Sounds awfully chilly for a reef aquarium.


Not at all. I've even seen temps in the high 60's with no problems.

http://images.tapatalk-cdn.com/15/12/07/c2b1eb4dd7ddae1056f9f8340002fb88.jpg

[mizzoumed02]

That's not a bad swing. My Apex shows mine goes between 77.7 and 78.2. I think any swings less than 3 degrees is acceptable.

[tmz]

Natural reefs experience much greater swings than those noted. FWIW, my aquariums thrive in the 77 to 80 degree range,

[Coelli]

Looks exactly like my graph, though I have my on/off at 77/78. :)

[jason2459]

I love that the Apex can use the seasonal table. I've switched to that and just let it do it's thing.

Fallback ON
Set OFF
If DTTemp < RT+0.0 Then ON
If Tmpx9 > 81.0 Then OFF
If BMTemp > 81.0 Then OFF
If DTTemp > 81.0 Then OFF


That actually powers on and off a Ranco controller which has a set point of 82 which I have two Jager's plugged into that with set points of 84.

[Starvin Marvin]

Hey,

My heaters don't have their own controller. Good advice and thank you for sharing, about the fallback Member No 1.

Thanks to everybody who shared your comments!

Oh and the purpose of the Min Time statement is sort of experimental, to level out the curve. I was running 2 heaters previously and the 600w would heat up my system quickly. I found that they were faster than my sump could exchange the water or something, and since my temp probe was in DT and both heaters in Sump, I was getting weird results.

So I put that on one of the heaters and set the other to a lower point. Then I removed it.

Never tried removing the Min Time..

[Keoki18]

Hey Marvin

Saw this thread and was interested because I have been experimenting with this "ideal temp swing" as well. If you are just trying to maintain a beautiful reef, keeping the temps within a degree or two is fine. I have been working to spawn some of my corals, so I am slowly adjusting temperatures (along with other parameters) through out the year.

What I noticed is that subjecting the corals to a wider span of temps (gradually) preps them better for a catastrophe with a heater malfunction. I had a few SPS that I fragged from the same colony and split them in two different systems. One had very good temperature stability (+/- .5 F), the other was horrible as I had it in my sun room (+/- 5 F). During a power outage while I was away, I lost most of the SPS in the stable system as opposed to no loss in the fluctuating one.

Guess it all depends on what you are looking for, but that's my two cents.

[jason2459]

Some of my corals spawned this past year. I have no idea if it helped but I have my heaters, daytime lights, and lunar lights(timing and intensity) all based on the seasonal charts in my Apex. I even have my two gyres setup alternating directions in coordination with the Lunar timing (so it varies every day) and offset for the earth's friction much like tides. I even have them ramp up and down their speed like peak low/high tides in tidal zones.


My fish appreciated the snack
http://images.tapatalk-cdn.com/15/12/10/15ca52b1e55f8fe040b3b3b0285816df.jpg

[tmz]

Speculatively speaking ,there are different clades of zooxanthelae and some suggest a broader swing in temperature encourages more variety and more tolerance for unintended seasonal upward swings in temperature as a consequence. However, while some natural reefs have significant swings ;some are pretty stable temperature wise.

[dkeller_nc]

Hey,
I found that they were faster than my sump could exchange the water or something, and since my temp probe was in DT and both heaters in Sump, I was getting weird results.

I'd suggest that having the heaters in the sump and the temp probe that controls them in the DT is exceedingly dangerous, especially if they're the type that don't have their own thermostat (like a Finnex, for example).

If the return pump were to fail for any reason, the DT temp will fall, and the controller will set the heaters to "on" - forever. In a large system with powerful heaters, one could actually boil the water in the sump.

If you've some reason that you must have the temp probe in the DT (the sump's in the basement, for example), I'd strongly suggest adding an independent temp controller to the heaters, or add a module to the Apex with a separate temp probe that can be placed in the same sump compartment as the heater and used as a safety shut-off.

[tmz]

Good point ^

[jason2459]

Yep can be very bad.

I have a basement sump and use a temp probe in the display and two in the sump. I set the main temp control to the display temp but use all three as failsafes along with the ranco controller and heater's built in.

[hkgar]

I have Apex, sump in basement, probe and heaters in sump, MH lighting on DT. Here is my temp graph
https://www.reeftronics.net/graphns.php?probe=01&period=week&member=garyk

PS you might want to consider a free reeftronics.com account as they will send an email if your Apex isn't communicated with for an hour, i.e. notification of a power failure with the APex

[Starvin Marvin]

Many thanks to everyone - i just saw some of the latest replies and I appreciate the advice about:

(a) The "training" of corals to withstand wider temperature swings. Thanks Keoki18!

(b) DT vs Sump heater and temp probe placement. I have programmed in fail safes but I will now add a 2nd temp probe to the sump. Thanks dkeller_nc!

(c) Reeftronics website. I'm definitely going to start using that. Thanks hkgar!