I have a 125 gal
freshwater aquarium with two Marineland Penguin 350 HOB
filters (for now). I bought a Marineland Visi-therm 400 watt heater which worked great for 2 months then stopped heating. Woke up one morning and water dropped to 66 degrees.
So now I bought 2 Fluval E 300 watt heaters and I put both in my tank. I followed the instructions and I waited a little over 30 minutes to plug them in so I plugged them in around 5 pm central time and the initial temp reading was 67.5 on both and also was flashing blue because of the low temp and LF for the low flow was cycling on the LCD. Now this morning the LF has stopped but the temp only rose to 75.5 degrees. So for over 14 hours shouldn't they be working better than that. I bought 2 of them because 1 is rated for a 100 gal
tank so I figured 2 would be more than adequate.
I do not have a wavemaker or powerhead to increase the flow of my water yet. I have read that they need a lot of flow to work properly. I was going to buy something today but I just dont want to buy something if it still will not help correct this problem.
So any help would be useful.. Thank you for your time.