MD-40RT - 822 GPH - Iwaki Japanese

Iwaki MD-40RT
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MD-40RT - 822 GPH - Iwaki Japanese

100% Recommend this to a friend (5 of 5)

SKU: 300404

reg. $319.99

Special Price: $271.99

In Stock: 7
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Quick Overview

Why does BRS recommend this?

Anytime we need an external pump the Iwaki Japanese motors are our first choice.  There are cheaper options that work just fine, however when it comes to noise the Iwaki Japanese external pumps are class leaders and for any area where noise a concern and space is limited. The Japanese Iwaki pump is the way to go.

  • Japanese Motor

  • Max Flow: 822 GPH

  • Max Head: 21.3 Ft

  • ¾” Inlet(MPT)/ ¾ ” Outlet(MPT)

  • Max Amps: 1.3

  • Motor Output: 1/12 HP

Note: The Iwaki MD pumps' power cords do not come with the plug pre-spliced.


Full Details

External pump from Iwaki, the world leader in small magnetically coupled centrifugal pump technology. Japanese-made motor is designed especially for aquatic applications. Super quiet and energy efficient with less parts.

High quality external pump with years of research and development behind its design. Iwaki pumps offer high pressure rates in a durable, compact pump. Easily tailor pump applications because of the numerous motor/pump configurations. MD stands for Mag-Drive.

MD Series – Japanese Motor

  • Japanese motor is made from cast aluminum with a cast end bell
  • Japanese uses a custom pump design specifically for aquatic applications
  • Japanese pumps run cooler to the touch and slightly quieter, due to the thicker material

Quick Compare - Iwaki MD Pumps (Japanese Motors)


Power Usage

Maximum Flow

Maximum Head


Iwaki MD-20RT


492 GPH

14.1 ft

Hose 5/8” NPT ¾”

Iwaki MD-20RXT


822 GPH

8.2 ft

Hose 1” NPT 1”

Iwaki MD-30RT


600 GPH

17.7 ft

Hose ¾” NPT ¾”

Iwaki MD-30RXT


1140 GPH

13.5 ft

Hose 1” NPT 1”

Iwaki MD-40RT


822 GPH

21.3 ft

Hose ¾” NPT ¾”

Iwaki MD-40RXT


1344 GPH

15.4 ft

Hose 1” NPT 1”

Iwaki MD-55RLT


1104 GPH

26.9 ft

Hose 1” NPT 1”

Iwaki MD-70RLT


1536 GPH

31.8 ft

Hose 1” NPT 1”

Iwaki MD-100RLT


2136 GPH

39.0 ft

Hose 1” NPT 1”


5 Items

  • Awesome addition By Tory on 12/15/2015

    I purchased this pump to deliver salt water I make in a 55 gallon drum in my basement up approximately 14 feet into my sump. No more caring water up stairs for water changes any longer. Works perfectly! Using ball valves and PVC I also plumbed this pump to do the mixing for me. How convenient is that! Sure takes all the hard work out of doing water changes.
  • Very pleased By TheStarFishMan on 3/11/2015

    I ordered two of these for a 180 gallon tank upstairs with 10 feet of head. Both have arrived and testing them looks very promising. They are reasonably quite, well built, and work well so far. The trick is whether or not after 1 year will they still be running strong!? That remains to be seen. But so far they are looking very good. Pricey well maybe but worth it for sure.
  • Great Pump...a little loud By Dave on 3/4/2015

    This is a great pump as far as size and power. I have it hooked up to feed two lines one for a BRS Dual GFO & Carbon reactor and a BRS Bio-Pellet reactor. It seems to be perfect for the setup GFO on a gentle tumble and the bio-pellets in a fairly active tumble. Originally I had it connected to a Iwaki MD-20RT (that thing was dead silent) but it just didn't have enough power to really run both for me.

    No buyers remorse on this pump, but it doesn't get a full 5 stars because of the noise.
  • Strong pump By A on 7/16/2014

    Strong little pump with a perfectly sized fan. My pump has been running basically nonstop for over 18 months now. I have this pump pushing water up about 8' and through about 30' of pipe. It is also running a biopellet reactor and a GFO/carbon setup. The remaining water then goes through a small SCWD. I have never measured the output but it seems to work as a return for my 40. When I upgrade to a 75 I intend to use the same pump minus the SCWD. It draws about .7 amps according to my kill-a-watt, so pretty good for what I am asking of it. The output vibration does need to be isolated. I replaced the hard line I had coming out with a 1" vinyl tube for about 2 feet.
  • Nice pump a little loud By Aaron on 4/20/2014

    The pump fits my application perfectly. It's installed on my basement sump. I was really impressed with the flow rate as I made some unanticipated plumbing changes and still had plenty of flow.

    The one downside is it makes more noise than anticipated. I didn't use any flexible piping in my system so some of the noise is from the vibration through the hard pvc piping. I will be trying to break the piping to get rid of some of the noise. Also plan on changing the mounting of the pump all in an effort to change the noise. The pump right now can be heard on the first floor, so I will be spending sometime to get some of the noise out of the system.


Ask a question

Product Questions

Would you recommend this pump for a basement sump set up for a 125 mixed reef tank i am setting up. About 12 feet of run back up tank?
Question by: Ken on Jan 3, 2017 6:55:00 PM
Great question! This pump will be far under powered for that application. You would need a pump that will have around 1000gph-1300gph after the 12ft head height. For example, this pump has 822gph directly at the output and has 21.3ft of head. That means, after the 12ft high run you should expect somewhere around 400gph coming out of your return lines. :-)
Answer by: Randy (Admin) on Jan 11, 2017 1:32:00 PM