MJ mod review

Luis Ochoa

New member
I did the MJ mod a while back and I like it but I guess I was specting more flow. I am not sure I will mod any more of my MJ. I feel for the money and time it took, I could have got a Seio 620 for a few dollars more.

What has been you experience with it?
 
Well i've done a mod to both of my aquaclears, and to the maxijet i just got a few days ago. Which one did you do? i just did the basic one where you chop off the output thing. I just took a knife actually and cut it back so that its flat with the rest of the powerhead...do you know what i mean? kinda hard to explain.

But i didnt notice very much added power, but it definately gives it a wider flow than what it was before. I think i may try another thing to it right now actually..i'm gonna try something to the intake part of it.
 
I did the one with the 1 1/2" PVC piece and the propeller.

I don't know how to post pictures here or I would atach one here.
 
I actually just did the mod to a MJ900 this weekend. Turned out pretty good for my first one. For the day or two it was working it doubled the flow in my tank, but yesterday for some reason the bracket that holds the propeler in place broke. Im going to make a new bracket today and get it working agian. Ill post some pictures of the flow once I get it working agian.
 
ya i was gonna do that one but decided i'd try the one where you saw off the output instead. But ya you're right...i would prolly rather just get the seio for a few more. specially since you'd be able to resell it easier. I'm sure no one here has a problem with modded powerheads (as long as the work!) but people who have never seen it before might be weary of it.
 
how would you guys compare the Seio 620 to a maxi jet 900 mod? I have a Seio 620, and I bought a maxi 1200 to mod. but I haven't done it yet. just curious to see if you think it would be worth doing.
 
How can you tell if the flow rate doubles after the mod? Is there some kind of meter for this?
 
For the kind of flow I want in my tank I need to get a couple of Seio620, once I have them, (probably next week) I will be able to compare. I know if I place the mj 2 inches from the surface it will create a nice turbulance on the surface and you can actually see the ventury motion on top of the PVC pipe. I don't know if you can measure the flow, but lets say that if I feed the fish putting the food right at the mj outlet the food goes all the way to the other side of my 55gal (48") very fast. The stream is wide, as wide as the PVC pipe. I used the small shroud and small propeller for the mod. Maybe the larger mod is better.
 
I read a lot of the Maxi Stream thread a while back and I remember reading that someone did a side by side comparison of the moded mj900 or mj1200 and the seio 620. It wasnt a very scientific test but they said that the mj mod felt like it was pushing more water.
 
I have 2 MJ1200's with the output nozzle cut off, and 2 900's that are not modded. Those 4 powerheads are on a wavemaker, and the only other flow is from my return, at about 300gph.

The 2 modded 1200's put out some pretty wicked flow, and they are even better becuase they restart in different directions, making my flow even more random.

I've been running that setup since mid feb. of this year. It may not sound like a lot of flow, but all 4 powerheads are at the very top of the tank, and they can still move sand around at the bottom.
 
How can you tell if the flow rate doubles after the mod? Is there some kind of meter for this?

i dont know if theres some sort of meter or something, but i have 2 of the aquaclear powerheads...the same model. So when i did my mod, i just compaired them side by side...the sawed off one put out a little more strength, but mostly just wider flow.
 
Is there some kind of meter for this?

A lot of people use a garbage bag. Let the pump flow into the bag with a stopwatch. Then dump the garbage bag into a container that will let you measure volume. If the bag was full of 5 gallons after 30 seconds, that would be 600gpm. Use very tough garbage bags :)
 
Is the body of the MJ the same? I mean, the 400, 900 and 1200 use a diferent impeller but the body of the PH is the same? If so I would think that when you mod the Mj it does not matter what you start with because you will replace the impeller anyways. Does this make sence?
 
<a href=showthread.php?s=&postid=8042492#post8042492 target=_blank>Originally posted</a> by Luis Ochoa
Is the body of the MJ the same? I mean, the 400, 900 and 1200 use a diferent impeller but the body of the PH is the same? If so I would think that when you mod the Mj it does not matter what you start with because you will replace the impeller anyways. Does this make sence?

i think the 900 has less windings in the unit giving it less power to turn the prop that is used on the mj1200 mod. i have had both different mods and the the one Ochoa has is the better of the two. i also use the seio 620 and it doesnt move as much water as the mj mod but the flow is wider.

-jesse
 
<a href=showthread.php?s=&postid=8043974#post8043974 target=_blank>Originally posted</a> by frontosa_man80
i also use the seio 620 and it doesnt move as much water as the mj mod but the flow is wider.

-jesse

Wow, I am shock, so maybe I should get the Seio 820. Or definatly finish the mod on the other two Mj I have.
 
fliger has the other type of mod and he can tell you that it pushes some water. the one i have has the screw type of impeller on it and a smaller PVC pipe.

-jesse
 
<a href=showthread.php?s=&postid=8045897#post8045897 target=_blank>Originally posted</a> by frontosa_man80
fliger has the other type of mod and he can tell you that it pushes some water. the one i have has the screw type of impeller on it and a smaller PVC pipe.

-jesse

I have the smaller PVC also. I wonder if I put two propellers if it would improve even more?
 
Two propellers do not increase the flow. If you use the most current propellers that are sugggested in MJ mod thread, you will get the most flow out of them. I believe its the Octura 1435 and 3035(maybe?) or something similar. If you get a chance and have not done so try skimming through the MJ mod thread in the DIY area. I think the thread is somewhere around 120 pages now. There is lots of good info in there about what works and what doesnt and what puts out the most flow.
 
Back
Top