View Full Version : What size generator?

09/16/2017, 09:06 PM
Looking at a General lp5500 5500 watts
I have a 125g reef tank - usual equipment, mag 12 return, leds, T5, skimmer, heater, various small pumps, apex
Any idea if 5500 is enough for the tank and some other household items? Fridge, lights, tv...
Is there a tool to test the wattage used by items?

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09/16/2017, 09:16 PM
Honda has one that will get you going.


You can check for the manuals for your products online or you could also get one of these, for more specific data.


Make sure that you pay attention to starting wattage needs (which is higher than) versus running wattage.

09/17/2017, 06:28 AM
read the sticker on each piece of equipment looking for the wattage..
Then simply add them up..

here are the formulas you might need to convert..
volts x amps = watts
volts/watts = amps
watts/amps = volts

09/17/2017, 07:52 AM
I have a 6200 watt gen and it ran all of my aquarium equipment, 2 refrig/freezers, microwave, large tv, 2 laptops, several fans and led lights, garage door opener. That may be as much as 4000 running watts, start up watts would be a lot more. Fortunately, not everything is starting at the same time. I ran this gen 24/7 for 7 days.

One thing to keep in mind is if you don't have a chiller, and I don't, you will go through a lot of frozen water bottle to keep the water temp in range. Using two freezers we could barely keep up. A stand alone freezer would have been nice.

09/17/2017, 08:50 AM
5500 should be enough for almost anything but AC. ...can even run furnace with LP or Nat Gas source since you are just powering the fan. You can run a room-type AC unit with one that might be smart if you are in a really hot/humid area where tanks can heat up like JTL has indicated.

You might have to cycle stuff like lights, heaters and fridges, but it is manageable.

Have a good surge protector if you have any sensitive electronics like Apex, or whatever. I don't mean Harbor Freight, but get a really good one made for generators and electronics - unless your generator is really nice and well over $1000-1500, don't trust it even if it says that it does not surge.

Don't forget to use your fuel stabilizer and run the carb dry after each use to keep them from gumming. If it is a Honda, then don't worry about anything... I recently fired up a big pressure washer that I had no run since 2010-2011 (or so, I don't even know) and the Honda engine started on the third pull.

09/17/2017, 09:21 AM
Echo that. I used a 5500 unit for many years and could run almost the entire house less A/C. I now have a 6500, not because I needed the extra 1kw, but because I want one that matched my transfer switch (and had to buy a new unit anyhow).