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SPotter
02/16/2017, 07:04 PM
I am thinking about replacing my Dolphin Amp Master 6250 return pump and was wondering which pump would be best? My fish room is about 25ft away from my tank. My return line is 1.5" all the way to the tank, then t'd off and reduced to two 1" outputs into the tank.

Thanks in advance.

slief
02/17/2017, 08:59 AM
Definitely the RD3 230.. It would be good to figure out head loss including friction loss but the RD3 230 is about 5600GPH at a 6' head. My guess (given the length of the run and assuming this isn't a basement setup) is that you'd never need to exceed 160-175 watts based on the display size. The RD3 230 has a 1.5 inch output but if there was a way to up-size the plumbing between the pump and the display to 2", that would reduce friction loss substantially over the long run that you have.

SPotter
02/17/2017, 09:10 AM
Definitely the RD3 230.. It would be good to figure out head loss including friction loss but the RD3 230 is about 5600GPH at a 6' head. My guess (given the length of the run and assuming this isn't a basement setup) is that you'd never need to exceed 160-175 watts based on the display size. The RD3 230 has a 1.5 inch output but if there was a way to up-size the plumbing between the pump and the display to 2", that would reduce friction loss substantially over the long run that you have.

thanks scott! I did use the head loss calculator on the site and it has the RD3 230 as a pump option. my house is on a 3 ft crawl space and the fish room is in the garage so I chipped a hole in the foundation to fun all of my lines thru the crawl and up thru the floor.

slief
02/17/2017, 02:56 PM
thanks scott! I did use the head loss calculator on the site and it has the RD3 230 as a pump option. my house is on a 3 ft crawl space and the fish room is in the garage so I chipped a hole in the foundation to fun all of my lines thru the crawl and up thru the floor.

Good to hear the head loss calculator now has the RD3 230. I know we asked for it to be added but hadn't checked in some time.

I have two of the 230's on my system and have been running them for nearly 2 years now. They replaced Reeflo Superdart Golds and the RD3's are much more powerful and silent. At a setting of 150 watts, they produce the same flow as the Superdart Golds which drew 184 watts. For me, it's been a great upgrade and I truly love these pumps. They are comparable to the Hammerheads at typical head pressures. In fact, since the RD3 230's peak at around 6300 GPH, they should be comparable to the Dolphin you are looking to replace and use about half the power (230w vs 460w) at full power. I don't think you'd even need to run this pump anywhere near full power though. The biggest difference will be that the Dolphin does a bit better with higher head pressures.

SPotter
02/17/2017, 03:36 PM
i just put the watt meter on my dolphin pump so see how much its really pulling.

slief
02/17/2017, 06:19 PM
i just put the watt meter on my dolphin pump so see how much its really pulling.

How much is it pulling? I just went by the specs. Head pressure tends to reduce the current draw. As such I wouldn't be surprised if you were below the rated spec.

SPotter
02/17/2017, 07:35 PM
It's pulling 350w. I never understood how more head pressure reduces draw. I would think the more head pressure the harder the pump needs to work. So with the RD3 I can control it by the wattage?

slief
02/17/2017, 08:07 PM
It's pulling 350w. I never understood how more head pressure reduces draw. I would think the more head pressure the harder the pump needs to work. So with the RD3 I can control it by the wattage?

Yes. With the RD3, the controller sets the flow rate and displays the actual wattage and the present setting. It will only draw 230 watts if it's running at full power. On my closed loop RD3 230 which is controlled via my aquarium controlller, I have it set to run at 60w at night to save power. During the day it runs at 120 watts and kicks up to 170 watts when my Tunze's go into flush mode to suspend detritus and get it into my overflow. I've also found the wattage displayed on the RD3's to be nearly spot on according to my Kill-A-Watt.

As for how or why increased head pressure reduces power consumption, I think (and could be wrong) that the increased head reduces flow and forces the motor to run at a lower RPM. The end result is that the motor in theory would require less current due to the lower rotational speeds.

biecacka
02/20/2017, 11:26 AM
Scott, instead of a new thread ill ask here. I am considering replacing my goby gold return pump. 1.5in inlet and outlet. I have it throttled back about 30% and feeding a manifold. which return pump would you recommend?

Thanks
corey

slief
02/20/2017, 12:58 PM
Scott, instead of a new thread ill ask here. I am considering replacing my goby gold return pump. 1.5in inlet and outlet. I have it throttled back about 30% and feeding a manifold. which return pump would you recommend?

Thanks
corey

I'd probably go with the RD3 150. It will fit the inlet and can be easily adapted from the 1.25" output to your 1.5" plumbing on your system. The RD3 80 would likely be too small for your system and the 230 would be overkill not to mention that it has a 2" input. Granted, since you will never use it at full power, you could still go with the 230 but I'd still suggest saving the money and running the 150. IT's essentially the same pump as the 230. Just a smaller power supply in the controller and different volute/impeller combo.