Maelstrom 5 1/4" Dual Bay Reservoir

Price: From $89.95 to $279.95
Out of stock
Bulk shipping information: 20 Pcs/Ctn

Product Options


Designed in the USA
ROHS Compliant
Product Description
The Maelstrom 5 1/4" Dual Bay Reservoir is an advanced, versatile, and elegant coolant storage & recirculation system capable of operating either as a standalone unit, or with a single or a dual MCP35 class pump (MCP350, 355 or 35x).

The product is available in 5 versions:

  • Basic standalone reservoir
  • With factory pre-installed MCP35X housing (no pump) for DIY upgrade purposes.
  • With factory pre-installed MCP35X2 housing (no pump) for DIY upgrade purposes.
  • With factory pre-installed single PWM controlled MCP35X pump.
  • With factory pre-installed dual PWM controlled MCP35X pumps.



Tab 1



Instant visualization of coolant level, cool factor:

Fits in two 5 1/4" Bays with or without the pump(s) installed
The image to the left shows the Maelstrom bay reservoir filled with various coolant colors.


Versatility, upgradability, extreme performance capability:

Modular design
The Maelstrom operates either in standalone mode, or with one or two built-in Swiftech MCP35x series pumps (MCP350, 355, or PWM controlled 35X) using an MCP35X-H (for single pump) or an MCP35X2-H (for dual pump) housing - All options are factory pre-installed.

Instant visualization of critical temperature data (*see notes below)

Coolant temperature display (in degrees Celsius)
Precise coolant level monitoring

Graduated level
Convenience & safety: Easy filling, no spills

Extra large fill-port opening with finger-grip ribs on the chrome plated brass cap

Reliable operations

Anti-vortex/anti-bubbles system
A tube surrounding the pump inlet features various size openings in its wall and prevents the formation of a vortex, and air entrainment in the loop
An open-cell sponge further traps micro-bubbles before their can re-enter the inlet
Performance, versatile loop configuration

Up to 3 return lines can be installed for loop parallelization.
Shown here with 3/4" compression fittings to illustrate compatibility
Cosmetic appeal: elegant and robust

Solid black-anodized aluminum face-plate with robust brass inserts for invisible fixation

Cosmetic appeal: light up the coolant, cool factor

Two pre-drilled holes for installing 3mm diodes 
(1 UV-LED is included)
Compatibility with all existing G1/4 fittings (compression, etc..)

G1/4 port standard
Included 1/2" hose barbs & hose clamps

Bonus: reduced cost of ownership (not included by our competitors)


* Notes regarding coolant temperature data:
When assessing various component temperatures in a conventional (non-refrigerated) liquid cooling system, ambient air is the primary baseline from which everything else derives, i.e. no heat-generating component can ever be cooler than, or equal to ambient. The second temperature data that can also be considered as a baseline is the coolant temperature: it reflects the sum of the ambient air temperature plus the temperature resulting from the component(s) heat load multiplied by the thermal resistance factor (in layman terms the heat dissipation efficiency) of the entire loop.
Thus, monitoring the coolant temperature in a liquid cooling system is essential at two levels: 1/ as an absolute value, you can monitor the cooling system health and be visually alerted of potential issues (overheating), and 2/ as a relative value compared to that of the ambient air, it provides a meaningful indicator of the system thermal performance and in particular its ability to dissipate the heat generated by the components under load. In this respect, the following table may provide a general guideline to assess the thermal performance of your liquid cooling system; please note that audible noise considerations will dramatically affect the qualifiers listed below. In effect, the lower the noise requirements are relative to the heat load, and the higher the thermal efficiency demand will be placed upon the system.

Coolant Temperature Minus Ambient Air temperature

System qualification

Less than 5°C Extreme system
Comprised between 5°C and 10°C Extreme to High-end system
Comprised between 10°C and 20°C High-end to Mid-range system
Comprised between 20°C and 30°C Mid-range to Entry-level system

Tab 2

PQ Curves with MCP35X and MCP35X2, and comparative data against all Swiftech pumps

Tab 3

Maelstrom Dual bay Reservoir (Standalone)
  • Face plate: Black anodized aluminum
  • Reservoir: Clear Acetal
  • Brackets: Nickel plated steel
  • Fill cap: chrome plated brass
  • Fittings: black painted (electrophoresis) brass
  • Pump inlet: Black POM

  • 16 Oz (453g)
Coolant Capacity:
  • 234cm3 (7.9 fl oz)
Temperature controller
  • Molex 4-Pin power connector
  • Operating voltage: 5v
  • 3mm - UV
  • 3-Pin connector

Pump Housing installation details

MCP35X-H Housing

The MCP35X-H Housing installed

MCP35X2-H housing

The MCP35X2-H housing installed

Related product specifications

Precautions for use

  • The recommended coolant is Swiftech's HydrX or Hydrx PM. Swiftech's product warranty does not cover the use of 3rd-party coolants.
  • The use of coloring additives and/or UV dies containing particulate fillers may damage your pump bearing and may void your pump warranty.
  • The use of any additive or coolant containing alcohol is prohibited and dangerous: it will result in permanent damage to your acetal reservoir and may result in catastrophic leaks.

Tab 4


Installation Guides





Tab 5

Swiftech® Maelstrom 5 1/4" Bay reservoirs receives Tech of Tomorrow Editor's choice Award - Read More
"Swiftech took a seemingly simple idea and turn it into a viable product that steps up the bar for reservoirs in today’s modern PCs"

Swiftech's Maelstrom bay reservoir receives Editor's Choice Award from Tweaktown! Read Article - Product Page
...but I can speak for the standalone Maelstrom we just took a look at, and I have to say I am really impressed..listing price of the Maelstrom as you just saw is worth every penny and some."

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End User Reviews

(33 Ratings, 4 Reviews) Average Rating:
Not Bad
Allen Mesner (Greensburg, PA) 12/2/2013 8:21 PM
Once I set the pump speed to quiet this works amazing, can't even hear it running and everything is remaining nice and cold. I only have 2 complaints and they aren't even that much. 1. I wish the LCD could come in other colors 2. When I went to install this it did not want to sit level (like when you go to install a cd drive it would just slide in and line up with the holes) I had to work to hold it level with the screw holes and try to install it at the same time. Perhaps they could add a small strip of metal just to help with installation. Aside from that though would recommend
Great addition to my loop
MT Alex (Montana) 1/14/2013 1:39 PM
I am thoroughly enjoying my new Maelstrom-SPH. I was previously using a Rev. 2 reservoir, which performed adequately. One of the benefits I am really enjoying from the new res, whether intended or not, is that my pump is significantly quieter. I would imagine that it is inherent to the design, mass and mounting of the larger bay res. It is many levels quieter than the standard neoprene pad mounting system on a bare pump. Anyone who is complaining about noise from this pump probably doesn't have their 4-pin PWM connected to the motherboard correctly, or haven't adjusted their temperature curve in their motherboard BIOS. It is virtually silent until you need the performance, then it ramps up itself. That, not to mention it's phenomenal power, is the real gem of this pump setup.
Home Builder
Max (Va) 12/1/2012 10:55 AM
I purchased the Maelstrom Dual Bay and after finally receiving it from the west coast, I spent several hours water blocking my custom PC. I pressure tested all the parts I assembled then attached the Maelstrom and began to fill the system, but after about 1/4 full the Maelstrom began leaking. Needless to say, I was not happy. I cleaned up the mess, pulled the Maelstrom out and discovered the connection between the reservoir and motor was not screwed down, the nut was just lying inside the fill chamber under the foam and screen - After taking care of quality control - I re-attached and filled; no leaks this time and the unit pushed the liquid through my system. Pros: Seems to be powerful. Has a built in water temp readout. Allows constant visual monitoring of levels. Cons: Poor Quality Control - it leaked due to a connector nut was not tightened inside. Loud - So much for my quite system :( Recommended Improvements: Please adapt the use of modular wiring harness, currently has two of each all wired together. hint - like power supplies. Improve the noise level - The unit is way too loud, had I know it was this loud, I would have purchased a different unit, which I may do anyway. Please Check the unit before shipping.
No different than any other Dual Res Pumps out there...
PNugg (Houston, TX) 9/22/2012 3:36 PM
Pros: 1) LCD temp readout - nice touch. 2) All in one unit, came completely built with MCP35X2 & both pumps. VERY NICE. Just plug it & use it. 3) Great INITIAL Customer Service (Front plate was 2mm wider than in needed to be, but they sent a replacement front plate trimmed to size within 3 days !!!) 4) Great head pressure - this thing is powerful. Visually the water flow is much faster. Too bad I don't have a test gauge to provide any numbers. Cons: 1) THIS THING IS LOUD !!! I have a two other Dual Res/Pumps from Koolance (the RP-402x2, it's quiet & RP-452x2, very quiet). 2) NO TEMP DIFFERNCE between the Koolance Dual Res/Pumps and the Maelstrom, and I have an SR-2 w/2 X5690's & using 1x360 & 1x480 rad and it's still at 30C. I was hoping for at least a 2C to 3C lower, guess not. 3) No way for you to fill up the Res (periodically) through the front (like you can with Koolance Res units). They have to be unscrewed and pulled out to fill. Don't like that. 4) Even though LCD readout color works out for my "green" PC build, it should be in different lit colors (red, blue, purple) and not just green. 5) Can't get rid of the BUBBLES !!! Now I actually like the bubbles (because I like to SEE the motion of the fluid traveling), but as a result the LOUDNESS kicks in and won't go away. 6) The placement of the UV LED lights were not good. Barely lights up the UV fluid, where with the Koolance Res units really lit up nicely. Especially if you want to show off your UV color. 7) NOW, this time around Customer Service has is EXTREMELY SLOW in getting back to me and mind you - I'm a reseller for this company. I've tried 3 separate times (within the last 2 weeks) and left three separate messages with the front desk person when I called to have either Gabe or the other tech guy call me and not a word back from them yet. Very Disappointed. In the end, I rate this product just okay... Now with this review lets hope they get back to me...
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