Ok... so my husband has a 210 gallon that we'd like to keep consistently warmer. It's run on an FX5 and FX6 and, when seasons change, we often end up having to add or subtract heaters, adjust temperatures, etc. How have others handled heating large tanks? Obviously we need multiple heaters (we do have multiple very large heaters). I've contemplated adding controllers, but, with the wattage we'd be looking at, I'd be dealing with multiple controllers which might cause some of the same issues we're experiencing with multiple heaters anyway (temp settings being inconsistent, some working over-time while others turn off, etc). Thoughts? I want to know what others have done.