Almost 14¢ from what I'm reading:
https://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_5_6_a
That's closer to $50.
I didn't hear the conversation, so if you still think the folks were trying to lie for some reason then you're probably right.
But...
If they just whipped out a number to make a point about power-efficiency, then I would try not to feel so harshly about it.
They may have been thinking about a full power reef install vs a minimal one like the one you linked.
The same truth still applies. If you compared that T5 system you linked with a comparable LED system, the LED system would use significantly less power.
The difference can actually be really extreme if you're requirement isn't to match the T5 system per se, but simply to grow coral well. Even many (perhaps most) stony corals can adapt and do fine at very low light levels, as long as you pay good attention to flow and nutrients in the system. (High flow and non-zero nutrient levels.)
For example, my low-light tank (36x12x19"H) runs on a DIY LED fixture that uses about
28 watts, which gives the tank about 10,000-15,000 lux at the water surface. (Around 150-300 PAR.)
That light is running the same tank that I used to light with a
300 watt metal halide system.
Those systems aren't comparable in the sense that you could switch a tank full of corals from 300 watts to 28 watts.
But they
are comparable in that you can choose either set up for a new tank. In that case, it's at your discretion.
So for a new tank the size of mine, you really would have the option of choosing either a
$140/year power bill or a
$13/year power bill.
Noteworthy that the $140/year option also carries bulb replacement costs on top of that....so the yearly costs of a T5 or halide system are
at least $140/year....more like $200-$250/year total.
My 300 watt system used Radium bulbs, which ran me about $90 each.
So for me, that was $320 in yearly costs down to $13 a year.
(NOTE: I actually switched my tank exactly as described 4-5 years ago and bleached most of my corals, which were huge and grown up to the surface of the water. Don't switch a tank like that.
Remember what I said at the beginning. Basically, you're more free to pick the level of light you want at the beginning, when you're setting up a new tank with frags. Hard lesson for me. I didn't even use a light meter back then or I'd have known exactly what was happening. I use a LX-1010B lux meter for everything now.)
In terms of $$ on your electric bill, I would never have been able to quote a number to someone....I use a calculator like this one the power company has on the "how to save money" section of their website:
Appliance Energy Usage Calculator
I hope that helps....and if you maybe think the store deserves a second chance now, give it to em!
(I realize maybe not too.)
