It would be proper protocol to have a licensed electrician hook it up. An electricians job ends after all the wires are landed in the proper place, and are of appropriate size. Don't expect an electrician to deal on the technical control side of things. Some do, some don't.
AES carries one manufacturers brand that has a pretty neat unit out now. AES doesn't have them on their web site.
One of the units that AES sells has an over temperature protection device. This is a one shot device meaning it will blow, similar to a fuse, and needs to be replaced. It was the model that Greg Grimes posted earlier in this thread.
I looked at that one (1000 watt model) because it is reasonably priced. This would be the only offering from AES that I would be interested in.
It's on my list of possibilities. I'll just bypass the over temperature device, should I go that rout. I have other methods of dealing with over temp. that don't require replacing parts.
One thing I am finding out on some of the aquarium heaters is that the actual elements are made from Aluminum mesh. From what I have found out, Aluminum mesh elements can not handle too many on-off cycles before they are toast. A PID Loop would probably kill one in short order. I'll try one tho. Whats the difference in melting temperature between Aluminum mesh and Tungsten?
If you did not know. The elements are inside the sheath material. In the pic. you see the long tube. That is the external sheath. They make them from various materials like Stainless Steel, Monel, Titanium... The heating elements are inside the sheath. You can get heaters that look like a bunch of skinny rods all formed up (bent) in many patterns. These also have an element encased in a sheath. Big problem with these is that if there is any organic build up, the build up will insulate it from the water, requiring more power to do the job. Not intended at all for this type of service. Clean Fluids!!!
Still have to clean any type of heater in an RAS on a regular basis. I'll know when it's time by monitoring current and temperature.
Still trying to figure out the best place for the heaters. It will be after the primary filter, but thinking before the biofilter. That way I can probably keep the biofilter a bit warmer than the tank. Defiantly don't want it in the tank.
Biggest problem on the consumer side of things, is there are really no technical specifications one can reference. About all they have are buzz words and marketing glitz!
I just got a Chromalox catalog, but haven't had the time to open it up. Another brand I am looking at is Watlow. These companies have been in the biz for many, many years. Omega Engineering is another one, but they are a bit ridiculous on price.
Cheap Aquarium heaters have been the cause of house fires and a few electrocutions. One well known company recalled everything they ever manufactured on one model of heater they produced. Think it was like 1.2 million units. Kinda scary!
From what I have found out, Aluminum mesh elements can not handle too many on-off cycles before they are toast. A PID Loop would probably kill one in short order. I'll try one tho. Whats the difference in melting temperature between Aluminum mesh and Tungsten? 
