hello all my heater is not doing its job properly. I'm not even sure it works. the house seems to keep the water at the desired temp. its 500w.
I'm now looking into buying Fluval heaters. I am wondering if its best to have 2 heaters rather than 1? my tank is 6ft x 1.5ft x 1.5ft (LxWxD)and holds around 480l. I was thinking of getting 2 200w heaters and putting them at opposite ends under the filter outlets.
I used to have two heaters when I had the conventional 'in-tank' style ones, I found it was better than one. I had two 300w ones for my 350 litre (primarily because they came with it!) and then the same when I upped the tank size to 600 litres. I also tried the Rena Smartheaters that fit over the intake of the filter pipe, but I wasn't impressed with those. I've now got thermofilters and those are much better than any standalone heater I've tried, I wouldn't go back now
But going back to your original question, I'd go for two heaters on the back of the tank equidistant from each other and the sides. If that makes sense. That should help stop hot/cold spots as long as there is good circulation in the tank Plus if one fails then there other is still there.