It might be time for me to find some different heaters to run. I originally thought that three 300 watt Finnex HMO-300s with Digital Controllers would do the trick, but I feel like they're having a hard time keeping up. With about 360 gallons of total water in my system and a sump in the basement where the ambient temps are int he mid 60's I figured 900 watts would be sufficient.
Additionally the temperature controllers on all three of them is about 10* off. My Apex, a glass thermometer, and another digital thermometer read 77-78 and the controllers on the heaters read 87-88*, so it doesn't appear that I need to re-calibrate the Apex temp probe. This makes me somewhat uncomfortable as I prefer that the heater controllers be within their advertised +/- 2 degree mark as I intend to use their controllers as backups to the Apex should the Apex ever lose it's communication with the EBs.
I have the controllers on each of the heaters set to 90*. Then I have my Apex set to keep the heater outlets on until 78*. Once the water temp is 78* the heater outlets turn off. When the water temp drops below 77.6 the outlets turn back on.
Another weird thing I observed is that the Apex is reporting that the EB8 which I have the heaters plugged into (nothing else plugged into the EB8) is only using 3.7 Amps at max...I would have thought that three 300 watt heaters consume closer to 8-9Amps? Maybe my EB8 isn't monitoring the Amps correctly? I read some articles about potentially needing to calibrate the EB8s for Amp monitoring. OR the heaters really aren't 300 watts? I'm thinking I'm going to try my 'Kill-A-Watt' meter tonight when I get home from work to see if each heater is actually drawing the advertised amount of electricity.
Doesn't look terrible when looking at Fusion...
But when I look at the Apex App on my phone it definitely seems like it struggles to meet the 78* temp in the overnight hours. I'd prefer to see a more consistent and predictable increase to 78* then drop to 77.6* and repeat, similar to what happens between 2PM and 8PM.
I wish the Cobalt Neo-Therm heaters came in larger sizes; I really like them. I had two 200 watt Neo-Therms on my 90G and they worked perfectly for over 2 years. I'd probably need at least five 200Watt Neo-Therms at a minimum to heat my system.
Not sure which heaters I'm going to try next at this point...Might go with some Ehiem Jagers. Other recommendations are appreciated as well!
UPDATE - Just ordered three 500 Watt Finnex Titanium Heating Tubes. Going to control them with the Apex as I've already been doing, but hopefully these are sufficient for the rest of the winter. I imagine in the spring / summer I can take one of them offline.
Have you tried insulating the drainpipe, and return lines, as well as the sump? You could use hard foam board and then remove it in the summer. You could also put the foam board insulation on the underside of the stand for the display tank and sump. I'd imagine the pipe insulation could be a big deal by itself. You can get fiberglass wraps or batts and stuff it around the pipes.
I'm curious how much insulating reduces the need for heating since that's what I plan to do. Running your heaters costs money, for me it's about $1 for every watt (if it's running non-stop for the year - so in your case it would be more than $900 per year just on heating if the heaters ran non-stop).