How stable should tank temp be? aka Do I need a heater?

[glb]

Here’s today. The big dip was while I was calibrating my probes and it was out of the water.

 

[glb]

What brand heater do you all recommend? Finnex titanium?

 

[glb]

Ok so I tested the Cobalt heater I have which hasn’t been in use and it works fine. I’ll replace it soon, but in the meantime, I set it to 78. For the apex outlet, I programmed it like this:

Is this the right way to program it? I’ve read that it’s better to let the apex temp controller turn the heater off and on rather than the controller on the heater. If so, have I done it correctly??

 

[JGT]

77-79 is totally fine. My worry would be if you forget on those colder days. Best thing to do would be to put a heater in there with a temp controller. Hypothetically speaking the heater should almost never turn on if you set it up right.

Imo some temp fluctuation is actually a good thing

Agree. Get the heater just in case. Better safe than sorry. They are cheap enough.

 

[glb]

Agree. Get the heater just in case. Better safe than sorry. They are cheap enough.

Thanks! Is my programming ok?

 

[JGT]

Thanks! Is my programming ok?

Appears right although not sure it can get that specific. I’d do 77 on and 78 off. I would also set your heater to turn on at 76. This way if the Apex dies the therm on the heater would turn it on so your fish won’t freeze.

 

[glb]

Appears right although not sure it can get that specific. I’d do 77 on and 78 off. I would also set your heater to turn on at 76. This way if the Apex dies the therm on the heater would turn it on so your fish won’t freeze.

Thanks. So if I’m understanding everyone right, it’s better for the tank to run a little warmer if that means keeping the temp more stable. Today it started at 76.8 and and now it’s 79. I have another hour with the lights on so it will go up a little more.

 

[muggle reefer]

I run a 35 gallon red sea max tank and find my temperatures fluctuate from what I set as the low to a high near 78 or 79. I recently dropped my low temp to 76 to drop the overall range. I was set at 77. Because of the hood, I find I need to run a chiller not a heater. So I end up needing to set based upon the low point. I end up with 2 or 3 degrees fluctuation over the corse of the day. I have switched recently to leaving the front part of the hood open and the back which is reducing the run time on the chiller but I still don't drop below 76. I am not saying this is right or wrong, but it is not killing my fish or corals. I just keep some soft corals. I have always had temperature fluctuation in my tank running it with a hood. Before I ran a chiller, my temperatures were consistently too high and I killed things too frequently. We were sitting closer to 82. Inverts did not like it and anything new we put in the tank had a hard time survinging. After a year or two we started running a chiller and things got a lot better. We have been running in this manner for about 6 years.

I don't own an apex or anything, I just have a stick on thermometer that I put on the side of my tank when we bought it so we can always look at the tank quickly and see temp.

 

[Biglew11]

Salinity changes with temperature. So, it isn't the temperature fluctuation you should be concerned with, but the resulting fluctuation in salinity.

Sorry but the salinity in p.p.t. does not change with temperature. The ways that we measure it using specific gravity, refractive index, or conductivity does change. That's why we need temperature compensation. But 35ppt will stay 35ppt no matter the temperature. The salt content only changes when water evaporates or when we add fresh rodi water.

 

[Doctorgori]

I’ve had sw fish for decades, I dunno, I’ve lost entire tanks from heaters, “usually” never lost fish from being too cold... edit add: just remembered, we had a furnace fail, but even at 50f, losses were < 50%
really, anything above 70 is safe IMO
I see absolutely no issues with corals in my unheated seahorse tank, corals seem to grow fine in 73F water year round...it gets down to 70f, nothing looks unhappy so far...
but I agree, heaters: better to have and not need than to need and not have....my 210, I own a 300w Titanium Finnex controlled by Apex and set 77-79F FWIW
OTOH
If you have a large tank, modern insulated home and set your thermostat above 68 then IMO heaters add more risk than its worth it. I say ; Buy don’t use

 

[Dom]

Sorry but the salinity in p.p.t. does not change with temperature. The ways that we measure it using specific gravity, refractive index, or conductivity does change. That's why we need temperature compensation. But 35ppt will stay 35ppt no matter the temperature. The salt content only changes when water evaporates or when we add fresh rodi water.

That's right. You did mention this in a thread I posted previously.

Why does Temperature Effect Salinity?

I understand and accept that temperature impacts salinity. Salinity is a ratio of salt to water. If a 10 gallon tank has a salinity of 35ppt at 68 degrees, and then you raise the temperature to 74 degrees, the ratio of salt to water has not changed. So why the change in salinity?

www.reef2reef.com

@glb - Disregard my reply on this.

 

[Cole.mormon]

Id recommend a fluval

 

[Kershaw]

Years ago on a 120 gal tank, I was in a hurry and did a water change with 50ish degree water. It was about 40 gal. It dropped temp in my tank from 78 to 64. 8 fish and a bunch LPS. Lost nothing, I highly do not recommend it. Just seen the .5 temp split comment and figured i would tell my story.
I really don’t worry about temp changes as long as my tank stays between 76-80 winter it’s closer to 80 and summer closer to 76.

 

[glb]

Update. Thanks everyone for your advice! I have my heater set at 78 and the water temp has only fluctuated 1-1.5 degrees daily. What an improvement! R2R is the best!

 

[Ksull72487]

Preventing Temp swings is the biggest thing. 80 degrees isn’t a big deal if it maintains it. Your lights may contribute to heat during the day. You want a stable temp. So if your temp drops 4 degrees at night problem. You’ll set that heater up to compensate. A small temp swing isn’t a huge deal. Like 1 degree or two. But you want to try to maintain it. Your peak is going to be just before the lights turn off on a regular day. If it’s 78 then you keep that heater at 78. If it’s 80 hopefully not then you go for 80. You want to keep the temp in range 24/7. Some guys run hotter some run cooler.

The dual thermostat is just a safe guard. So you a temperature controller and heater. If you have 3 grand in corals in the tank the idea is the temperature controller does the work. If it fails you still have the built in thermostat on the heater itself. Saves you 3 grand.

 

[nkusumoto]

75-83 degrees. I have been through it and haven't lost a fish from a .5 of a degree fluctuation. 3 degrees rising and lowering maybe. My Red Sea sits at 76.7 degrees to 77.2. degrees at full ramp. I also have a portable LG AC unit to keep the room and tank cool. Don't forget to always have a back up heater. I always have 2-3 300 watts in sump.