If your not looking for a DC pump which I would personally avoid on the cheap end anyway, I would suggest a Fluval SP series pump. They use the Italian Askoll block which is a terrific block and will last many many years with occasional maintenance/cleaning. Their price is great, they are silent, run cool and very solid pumps. In all honesty, for an external pump, if I was on a budget, the Fluval SP would be my first choice. In your case, the SP2 may be too small depending on your head pressure. The SP4 is on the larger size but you could gate it down.
DC pumps are more efficient, they use energy more efficiently and put out less heat, because they utilize less power.
They also have a lot of adjustability. Like the Vectra, which is basically an MP10/40 for a return. Very powerful, cool settings and programmable, lower heat and energy usage.
That is not entirely true.. The Vectra for example puts out a lot of heat compared to other AC pumps and even DC pumps. It also uses about 10 more watts than it's power rating which goes to the controller. Just read up in the Vectra thread in the Lighting section here on the forum. In fact, the Fluval that I suggested above is an AC Pump and it puts out MUCH less heat watt for watt and gallon for gallon than the Vectra and is on par with most other DC pumps. And the only thing the Vectra shares in common with the MP's is the controller. The block for the Vectra is made by HiPool in China. This is the same company that makes the Deep Water Aquatics DC pumps though the Vectra block does have special windings for higher voltage. That's not to say that all DC pumps generate a lot of heat because most don't generate much but some produce much less heat than others.
Having said, given the track record of most DC pumps on the market, I am not a fan of running a DC pump for a return pump which happens to be the most critical component in our tanks. The one device where failures are unacceptable. AS such, there are only a couple DC style pumps that I would condone and those are unaffordable for most people. As such, I would stick with a quality AC based pump for a return unless cost isn't a factor.
How's the noise on the SP2 when ran external ?
How's the noise on the SP2 when ran external ?
They are VERY quiet! Damn near silent. I'd go as far as to say they are about the quietest AC pump you can buy and on par with some of the best DC pumps.