return pump size?

Setting up a new system to downgrade my existing system. The tank is 92 gallon corner with a 1" bulkhead. Curious what flow rate I should look for in a return pump. How many gph should the pump be? I think a one inch bulkhead is rated for 600 gph but I don't know if that is the rate my pump should be or if it should be a higher rating. Also, can the pumps be placed on reostat to reduce voltage?

Suggestions For low energy consumption pump for this setup.

 

Not sure what type of pump your are planning? external or internal? magnetic drive or direct drive there is a lot of choices.
If you want a top of the line magnetic drive pump that is nearly silent go with the eheim 1260 or 1262 either would be a good choice. MAG drives are also highly rated and proven long term. IMO a good magnetic drive pump is the way to go since they only have one moving part, no shaft seals to worry about leaking over time and are generally more efficient that external pumps. Most can be ran internal OR external as well. If your looking at making them draw less current all you need to do is put a valve in the output return line to your aquarium and turn the flow down this will actually reduce the power draw quite a bit and will NOT harm the pump in anyway. I know this sound odd but you need to look at it from a fluid dynamics way. The more water your moving the more energy or power it takes to move it.
Don't vary the voltage to the pumps their not designed for that and it will more than likely be hard on them.
Using the eheim 1262 as an example they use about 80 watts at 0 head put 5 feet of head on it and it drops down to less than 40 watts and pushes about 600 gallons per hour using a ball valve you can throttle it down a bit more.

 

Great info Jamie, I hadn't heard that about the Mag Drives.

 

Mag drives can also be very loud compared to others.

I've been away from aquaria for a while so am not up to speed on current offerings, but just thought to mention that. I had a mag 12 as a recirc and it was ungodly loud, as are the two I have mounted to a piece of equipment at work.

 

General rule of thumb for the return would be to target the processing capacity of your skimmer.

My skimmer processes 450 gph in my 72g system so my return is 420 gph.

-Eric