Maxi-Jet Modifications: Going main stream.
In my previous article we talked about a modification dubbed the “Hacksaw” method. This modification conservatively increased the flow of the Maxi-Jet 1200 to around 400 GPH. This approach was simple enough and does a great job of improving water flow in our aquariums. However there are additional methods of modification that will increase the flow to even greater numbers. While increasing flow is the main purpose for making these modifications. The reason for using the Maxi-Jet is to do it with as little heat generation and power consumption as possible. While many folks evaluate their needs and the pumps they are looking at by the gallons per hour rating, it is not the only rating to consider. Gallons per hour is a fine starting point, but just as important in making this purchasing decision is how many watts a unit uses and what the price of the unit is. These additional factors go a long way in determining how efficient a given pump is.
Powerheads and propeller pumps (Tunze and Seio) are very common devices for providing circulation in marine aquarium systems. Most conventional pumps use a rotating impeller to move water at a relatively high pressure through a relatively small opening. Tunze Stream, arguably the best pumps available, and Rio Seio pumps use propellers and turbine type mechanisms to move water at a relatively low pressure through a relatively large opening. It It is this simple design principle that allowed for further modifications and improvements on the Maxi-Jets. Following the design ideas of the Seio and Tunze pump, you can replace the impeller with a propeller and the impeller guard with a more open design. The DIY folks have come up with a way to take a model airplane propeller and 1.5" Schedule 80 PVC and replicate the actions of the Tunze of Seio pump.
To give you an idea, the pictures below show a couple examples of this type of modification. The picture (Below Left) is of a MJ-1200 and a MJ-600 with a similar modification. The MJ-1200 (Left) that has been modified by replacing the impeller guard and impeller with 1-7/8" housing and 1-1/2" propeller.
The MJ-600 (Above Right) has a 2" housing and a 1-3/4" propeller. In a test against a Seio 1100 (rated at 1100 GPH), the tester estimated that the Maxi-Jet produced approximately 1300 GPH. Considering that the MJ-600 draws only 7.5 watts and the Seio draws 21 watts, I would say that is a major improvement. Of course that is subjective, but does an eight times improvement in flow and a 2/3 reduction in power consumption sound like a good deal? In my opinion, it is well worth the few dollars in parts to create this update. To see one of these modifications in action, take a look at this 30 second video of a Maxi-Jet 1200 that has been modified. Maxi-Jet 1200 Stream Mod Video.
Now if you are like me and all thumbs when it comes to building some of these projects. You will find it is not always the easiest thing to do. Fortunately, there are alternatives. For instance, the modifications above were made by a member in our local MAS club. Perhaps there is someone in your club or location that could do the same. If you have a itch to build to build one of these modifications yourself, here is a parts list and location of where to get the parts.
The shroud:
-Schedule 80 1.5" PVC pipe (dark gray if you order from mcmaster.com part# 48855K25) for the 1.25" up to 1.4" propellers - Home Depot, Lowes, McMaster.com
-1.5" slip coupling for the larger 1.75" Dumas propeller
The propellers:
-1.38" Octura 2035 or 1435
-1.57" Octura 1440 or 1240
Octura props can be ordered from http://www.funrcboats.com/category.aspx?categoryID=109 or directly from Octura (they have no website nor email)
Octura Models Inc
(847) 674-7351
7351 Hamlin Ave
Skokie, IL 60076
-1.75" Dumas - Towerhobbies.com
(http://www2.towerhobbies.com/cgi-bi...p?&I=LXE472&P=0 or http://www2.towerhobbies.com/cgi-bi...p?&I=LXE473&P=0)
Everything else:
-0.098" carbon fiber rod - Towerhobbies.com (http://www2.towerhobbies.com/cgi-bi...p?&I=LXJDP4&P=M) or your local hobby shop
-3/32" 316 stainless steel welding rod - welding supply shop, mcmaster.com
-3.16" thin walled rigid airline tubing.- LFS, Petco, Petsmart, DrFostersmith.com (http://www.drsfostersmith.com/produ...&pc=1&N=0&Nty=1)
-Flexible airline tubing 3/16" ID - LFS, Petco, Petsmart, DrFostersmith.com (http://www.drsfostersmith.com/Produ...4&N=2004+113403)
-CA or super glue - Towerhobbies.com. local hobby shop, Home Depot, Lowes, Target, Walmart, etc...
-Cross brace: Can be made out of 1/4" thick scrap acrylic, 1/4" acrylic bars, or rigid airline
The pump:
Maxi-Jet or Aqua Clear or whatever else you have on hand.
If building one yourself or finding a local club member to make this is not an option, don’t sweat it. There are commercially available kits as well. The two main places are OceanFlo.com and MJMods.com.
On the OceanFlo.com site they sell complete kits for the Maxi-Jet 600, 900, and 1200. Each kit comes with a new propeller guard, propeller assembly, and mounting hardware. The mounting hardware allows you to adhere to various items to hold your kit, such as cleaning magnets or other bracket systems. OceanFlo states that they are currently out getting real data on the velocity output but in the meantime your have to go by the estimated numbers. Their kits provide a very wide flow stream and rival those claiming 3,000+ GPH. Until the accurate velocity data is in, they have chosen to be conservative in their numbers. Please see the charts below for kits and rates.
While the OceanFlo kits are a little more expensive. They offer a one year warranty and the kit is completely assembled. Personally, I like the design of their propeller guard. There is an area on the guard that is not cut out. This blocked area prevents a vortex being created when near the top of the tank. It also forces more draw from the bottom of the aquarium.
Note: OceanFlo has currently stopped production until further notice due to family illness.
On the other site, MJMods.com, you can purchase all the piece parts necessary to make the modification yourself. In addition there are kits listed for the various Maxi-Jet models. For example, the kit for the Maxi-Jet 1200 can be purchased for about $26(US). Keep in mind that this package is the individual piece parts and will require assembly.
So for the DIY's out there this is a great option. I was unable to find whether there is a warranty on their kit. I imagine that since this is a DIY kit , there is no warranty. In fact there is this foot note on their site.
"By ordering this kit you understand that this is a do it yourself project and you are directly responsible for the results. The time you spend understanding the directions before you build and the time you spend actually building with have a direct impact on your results. Thousands of people have completed this project with success and the project has generated a thread on RC with almost 140,000 views! "