Heater issue

fernalfer · May 16, 2016

Ok i have 2 Finnex 300 watt digital heaters this one: http://www.bulkreefsupply.com/finnex-hmo-heater-w-digital-led-controller.html

Now i set it for 79 degrees but yet with 3 different thermometers i get 74.9, 75.2, and 76. Now i'm testing in the display. Both Heaters are in the sump. 1 in the drain/sump area and the other in the Fuge. Is their just not enough turnover to heat the display and just the sump is getting to that temp?

Do i actually have to turn my heaters to like 83-84 degrees to get 79 in the tank?

I'm at a loss on what to do. Both digital heaters turn off at the same time because they are set to the same temp so i believe they are working properly.

any ideas?

My tank is a 120 gallon 48x24x24 have dual overflows and running to Jaebo RW-15 powerheads.

CodyRVA · May 16, 2016

Following, I have the same heater, I'm pretty sure I have mine set much higher as well to hold the proper temp. I have mine controlled by my Reef Keeper to maintain the proper temp.

twilliard · May 16, 2016

What temp does it default to when unplugged and plugged back in.

I recommend the true temp controller as the setting is not lost during a power outage and you can calibrate it.

The built in temp probe heaters just are not trustworthy
Here is a fine example of such a heater.
This is the via aqua 300w
Note the temps

Now this heater defaults to 78 when power is lost. You can emagine what this would do to a tank. (Caused a tank crash in the past)

fernalfer · May 16, 2016

So i'm still unsure whats going on in my situation

twilliard · May 16, 2016

Can't tell from the website but how long is the temp probe for the controler?
The probe must be upstream from the heater.

fernalfer · May 16, 2016

twilliard said:
Can't tell from the website but how long is the temp probe for the controler?
The probe must be upstream from the heater.

There is no temp probe.. It is just the heater and coming off the heater is a cord that runs to the digital controller where you set the temp and from the digital controller cord goes out to the out let.

jsker · May 16, 2016

I am controlling my finnex heater with my Apex, I have the heater where the return pump is a lot of flow. I have my probe before the heater is located. When I switch the heater to the sump It runs two 10th of a degree different than when it was in the DT. You might just have a bad controller??

fernalfer · May 16, 2016

jsker said:
I am controlling my finnex heater with my Apex, I have the heater where the return pump is a lot of flow. I have my probe before the heater is located. When I switch the heater to the sump It runs two 10th of a degree different than when it was in the DT. You might just have a bad controller??

well that means i must have struck bad luck because i have 2 Finnex heaters with controllers that shut off at the same time because both set at same temp. They both turn on to get to temp that its adjusted for and both shut off when temp is met, just can't get the same temp in the tank

jsker · May 16, 2016

fernalfer said:
well that means i must have struck bad luck because i have 2 Finnex heaters with controllers that shut off at the same time because both set at same temp. They both turn on to get to temp that its adjusted for and both shut off when temp is met, just can't get the same temp in the tank

Have you contacted Fennix? They are in Chicago IL made in the Us and they are really good with getting back with you.

fernalfer · May 16, 2016

This is a digital thermometer right next to my heater in my sumps fuge reading 74.9

this is the actual heaters controller reading 84. I don't get it. Really just unsure what temp my tank is at.

120reefkeeper · May 16, 2016

I always keep one of those old school little glass thermometers around just in case. I have two heaters running on my system hooked up to Apex. One of them I have set lower than the other . I believe one is set at 77 and the other at 78 . I control the off temp with the Apex. Basically my tank runs off one heater and the other is a backup. With this setup I have about 0.7 degree of temperature swing.

I've used those little black temp probs you have and they can be accurate and some can be way off. I'd pick up a cheap glass one and see what it says.

Btw we have the exact same size tank.

fernalfer · May 17, 2016

120reefkeeper said:
I always keep one of those old school little glass thermometers around just in case. I have two heaters running on my system hooked up to Apex. One of them I have set lower than the other . I believe one is set at 77 and the other at 78 . I control the off temp with the Apex. Basically my tank runs off one heater and the other is a backup. With this setup I have about 0.7 degree of temperature swing.

I've used those little black temp probs you have and they can be accurate and some can be way off. I'd pick up a cheap glass one and see what it says.

Btw we have the exact same size tank.

where do you have them located in your sump exactly?

120reefkeeper · May 27, 2016

fernalfer said:
where do you have them located in your sump exactly?

I have both in the fuge section of my sump.

Irsug1 · May 27, 2016

I would say turn up the temp until you get a good and consistent temp in the display. Take an average from your multiple thermometers for actual temp of the display.
Although do you have anything that would be affected by higher Temps in your fuge?
It could possibly be slow turnover as you mentioned.