How much does your temperature swing?

Be102 · Jan 21, 2019

So I recently took off an old heater from my tank because of water inside of it and not really being able to maintain a steady temp of what I wanted. I then added a newer heater only used for heating some saltwater and yesterday for the first time in a while I noticed my tank was actually on temp of around 78.

Today I wake up and look over and see that my tank has dropped since last night to around 74.

I mean it is 2* degrees outside so I understand why it would be hard to really stay as stable as I’d like it but I am curious if anyone recommends say turning the heater up to a higher temp say 80 and hope it can get up to it?

Buy another heater and just throw it onto my powerbar / profilux 4 and just have it turn on the outlet based on lower temps?

Just ignore it and let my tank be as nothing is suffering and the corals and whatnot seem alright.

Muttley000 · Jan 21, 2019

Sounds like you need more wattage to me if it can't keep up, I would add a second versus getting a bigger heater. Mine varies a degree because I have a Ranco inline with my Apex for redundancy as I heat with a loop on my house water heater and it could overheat the system quickly

Be102 · Jan 21, 2019

Muttley000 said:
Sounds like you need more wattage to me if it can't keep up, I would add a second versus getting a bigger heater. Mine varies a degree because I have a Ranco inline with my Apex for redundancy as I heat with a loop on my house water heater and it could overheat the system quickly

See that’s the thing, I currently run a 200 w which is ranked from 79-100 gallons but I currently got 65 gallon display and say 20 gallon sump. Maybe I should go for the next size up or just add another for the time being. The room is rather cold and the tank is sitting on an wall that leads to the outside.

lapin · Jan 21, 2019

I reccommend a second heater. My tank does vari depending on time of year and day or night. Stays between 78 and 80

Dr. Dendrostein · Jan 21, 2019

Be102 said:
See that’s the thing, I currently run a 200 w which is ranked from 79-100 gallons but I currently got 65 gallon display and say 20 gallon sump. Maybe I should go for the next size up or just add another for the time being. The room is rather cold and the tank is sitting on an wall that leads to the outside.

All that heat in the tank is chasing cold. So you're going to lose heat at one point through the night. Need more heaters. Bummer

PatW · Jan 21, 2019

Be aware that heaters have cheap thermostats. If the thermostat fails in the “on” condition, the heater can cook the tank.

I use my controller which has a temperature probe to turn on the heater below 77.6 and to turn it off at 77.7. I have a set of fans that turn on at 77.9 and off at 77.8. The system keeps the tank at less than a degree temp swing.

miPapareef · Jan 21, 2019

Be102 said:
So I recently took off an old heater from my tank because of water inside of it and not really being able to maintain a steady temp of what I wanted. I then added a newer heater only used for heating some saltwater and yesterday for the first time in a while I noticed my tank was actually on temp of around 78.

Today I wake up and look over and see that my tank has dropped since last night to around 74.

I mean it is 2* degrees outside so I understand why it would be hard to really stay as stable as I’d like it but I am curious if anyone recommends say turning the heater up to a higher temp say 80 and hope it can get up to it?

Buy another heater and just throw it onto my powerbar / profilux 4 and just have it turn on the outlet based on lower temps?

Just ignore it and let my tank be as nothing is suffering and the corals and whatnot seem alright.

I recommend add a second heater that is also rated for the full tank. Not only helps heat when temps are low, but gives you a backup if the primary fails. I’ve seen post of tanks with 2 or 3 degree temp swings without issue and I know form scuba diving the temps on the reef vary more that that. I just believe if we can keep the tank more stable it’s just one less stress on our system.

I use a primary heater rated for the tank size, but sometimes it can’t keep up. So a second heater is used for those times. I also have a fan that turns on if the temp gets too high. So the tank stays 78 +/- 0.3 year round.

Madmanmadrid · Jan 21, 2019

Idk if you seen the video from brs.they put a bunch of heaters they sell to the test as far as temp swings go. It's pretty interesting!

Livinlocal · Jan 21, 2019

When reading the recommended tank size for heaters, they are not very accurate.

If I were you, I would add a second heater. You can keep the same one, and buy a second heater that is the next size up. Having two heaters is also a failsafe for if one of them were to get stuck on, but then on the nights when it’s not as cold, only one of them will turn on to keep your tank where it needs to be. If it’s too cold, the second heater will kick on.

I have a water volume about 350 gallons, and supposedly at one 800 W Finnex should work, but since my tanknis in the garage, it sees much colder temps, where I actually need 2 800 W finnex heaters. Most of the time it only takes one of the heaters to keep my system, but on colder nights, it will run both heaters to keep my temperatures stable. I have it hooked up to my Apex, and as you can see, I don’t have temperature swings More than 1/2 a degree.

The first box is my sump temperature, and the second box is my tank temperature.

Calvin812 · Jan 21, 2019

I use a controller I got on Amazon for $35, it's a ink bird brand. It works great. You can set it at a certain temp and turn your heater all the way up if you wanted and it would automatically shut your heater off at the controllers set temp and back on when needed. It will keep your tank within a 1 degree swing. It also has a cool plug for a fan that would automatically kick on if the temp raised higher then the temp you have it set at. My tank stays at 77.2 and only swings from 77.0 to 77.4 and my house temp is 64 degrees at night here in Indiana.

Be102 · Jan 21, 2019

Calvin812 said:
I use a controller I got on Amazon for $35, it's a ink bird brand. It works great. You can set it at a certain temp and turn your heater all the way up if you wanted and it would automatically shut your heater off at the controllers set temp and back on when needed. It will keep your tank within a 1 degree swing. It also has a cool plug for a fan that would automatically kick on if the temp raised higher then the temp you have it set at. My tank stays at 77.2 and only swings from 77.0 to 77.4 and my house temp is 64 degrees at night here in Indiana.

Honestly I’m surprised I didn’t think about doing something similar with my controller. I should just crank the heater up and let the controller shut it off and whatnot.. great idea. Other than using it as a redundancy I can use it to actually get the right temp

Calvin812 · Jan 21, 2019

Be102 said:
Honestly I’m surprised I didn’t think about doing something similar with my controller. I should just crank the heater up and let the controller shut it off and whatnot.. great idea. Other than using it as a redundancy I can use it to actually get the right temp

Yea, some heaters dont keep a constant temp very well but a controller thermostat should keep it pretty close.

justmee · Jan 22, 2019

I live in Northern California and winter can get down to 39 degrees around the evening, and my temperature can fluctuate anywhere between 74 to 78. I use to worry about it, but it’s been like this for several years now, and all my corals and fishes have been okay. I’m sure ocean temperatures at night will drop also. I think a temperature between 72 to 80 will be okay IMO.

vetteguy53081 · Jan 22, 2019

For this reason, I have a titanium unit in both the tank and the sump. I have steady readings always

srad750c · Jan 22, 2019

PatW said:
Be aware that heaters have cheap thermostats. If the thermostat fails in the “on” condition, the heater can cook the tank.

I use my controller which has a temperature probe to turn on the heater below 77.6 and to turn it off at 77.7. I have a set of fans that turn on at 77.9 and off at 77.8. The system keeps the tank at less than a degree temp swing.

Controllers fail also, luckily I check my temp regularly.

redfishbluefish · Jan 22, 2019

I use a controller.....highly recommended....and it's rock solid 78.0 to 78.3.

Be102 · Jan 22, 2019

redfishbluefish said:
I use a controller.....highly recommended....and it's rock solid 78.0 to 78.3.

So I am beginning to think either my heater is just not calibrated correctly or like I just can’t keep a temp that is accurate. Do you have ur heaters set higher than ur desired temp and have the controller control it or what’s ur cycle like? Like I still have not seen above 76 since yesterday and it’s impossible the heater isn’t heating everything warm enough.