heating issues

BonelessEvil · Dec 13, 2020

up until recently, I've been able to keep my tank in a relatively small range, 77.5-78.5°, consistently and without problems; but then I redid my apex system after a crash. Now, having updated everything, I'm unable to keep the system at a relatively normal range. It lecture weights, going down as low as 74° and acting oddly. For example, I thought maybe the thermostat went bad in the peter itself (a cobalt neo-therm 200 W), so I replaced it with another. The problem still exists. I raised the temperature on the thermostat of the heater itself to 80°, while keeping apex's heater control at 77.3-78.3°. Still, this is the effect I've had. I can't figure out why it's still fluctuating so much. My thinking is that the heater itself should overheat (80°), but the apex should shut it off when it gets to 78.3°. But as you can tell by this image below, it just seems to be acting odd.

Could it be that my tank heater cannot keep up with the lowering temperatures during winter? (I've never had this problem before with the same heater)

tank: roughly 78 gallons/with sump
heater: cobalt Neo therm 200 W

BonelessEvil · Dec 13, 2020

So far, only one of my corals, a pink acropora, seems to be kicking the bucket, but that thing has survived a lot. Now, I've lost half of it. :-(

Flippers4pups · Dec 13, 2020

I would invest in another heater and run two heaters as a redundancy.

Brett S · Dec 13, 2020

It certainly seems probable that your heater just can’t keep up. What is the air temp in the room that the tank is in during the times when tank temp is dropping? If the air is colder during those times then it would suggest that the heater can’t keep up.

Have you looked to see if the apex is turning the heater on during those times and felt the heater to see if it’s actually warm and heating? If the heater is on and warm, but the tank temp is still dropping then you definitely need a bigger heater.

Finally, where is the apex temp probe in relation to the heater? If it’s too close to the heater then it can cause issues because the heater might be heating up the probe while it’s on giving you inaccurate readings.

Have you changed any equipment since last winter? Maybe a new return pump? All pumps will put some heat into the water, but some pumps produce more heat than others. Perhaps an old pump was producing more heat and helping to keep the tank warm last winter.

BonelessEvil · Dec 13, 2020

Brett S said:
It certainly seems probable that your heater just can’t keep up. What is the air temp in the room that the tank is in during the times when tank temp is dropping? If the air is colder during those times then it would suggest that the heater can’t keep up.

Have you looked to see if the apex is turning the heater on during those times and felt the heater to see if it’s actually warm and heating? If the heater is on and warm, but the tank temp is still dropping then you definitely need a bigger heater.

Finally, where is the apex temp probe in relation to the heater? If it’s too close to the heater then it can cause issues because the heater might be heating up the probe while it’s on giving you inaccurate readings.

Have you changed any equipment since last winter? Maybe a new return pump? All pumps will put some heat into the water, but some pumps produce more heat than others. Perhaps an old pump was producing more heat and helping to keep the tank warm last winter.

I suppose it's possible, though right now, the temperature in the house is 72. We tend to keep it at that, which is never been a problem in the past. I'm just not sure the thermostat on one side of the house is enough for my fish tank, on the other side. I'll take the other heater and put it back in. Thanks.

Brett S · Dec 13, 2020

BonelessEvil said:
I suppose it's possible, though right now, the temperature in the house is 72. We tend to keep it at that, which is never been a problem in the past. I'm just not sure the thermostat on one side of the house is enough for my fish tank, on the other side. I'll take the other heater and put it back in. Thanks.

72 doesn’t seem too bad. It looks like there was a big dip last night into this morning according to your chart. How was the temp last night and this morning? Was it much colder than the past few days? Did anything else unusual happen? You didn’t turn your lights on when you normally do or you had a pump shut off for some reason?

It also looks like it was warmer than normal yesterday evening? Anything unusual happen then?

dmy535 · Dec 13, 2020

I just did an update to my apex and was getting temp alarms all day for the temp bing too low, I checked my inkbird and noticed temp display was in the normal reading. Re calibrated the apex temp probe and no issues. Maybe the new update messed it up for you too?

Mical · Dec 13, 2020

By looking at your Apex chart 2 things stand out: A) the heater never raised temp higher than 76.8 & B) your heater has been ON for days. I'd say heater is too small and/or the calibration on the heater itself is WAY off.

vetteguy53081 · Dec 13, 2020

I’m wondering if heater wattage is inadequate.

BonelessEvil · Jan 3, 2021

thanks for the responses. Yes, I think the wattage is a problem. I have about 79 gallons worth of tank (including sump, but not coral/rocks). I tried putting in a 25 W cobalt heater alongside my 200 W cobalt. It's just not enough. I'm going to have to get a 300 W. 2nd, this winter was different than the last. Since I have doors now in this room, people were going out in the middle of the night (we have dogs) and that's when the temperature was dipping.