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View Full Version : Maxi-Jet Impeller Mod - Flow reduction

AJ_77
10-06-2003, 04:56 AM
Got an MJ1000 that I want to behave like a 900 flow-wise, so I'm thinking of taking the impeller and making a tiny hole in each blade with a drill and bit.

Anyone done something like this before? With the (hopefully) identical holes in each blade, the impeller should stay balanced, no? OR would this create turbulence within the body of the pump...
Aquattro
10-06-2003, 04:58 AM
Alan, I think it would create drag on the impeller and result in cavitation. Although for the cost of a new impeller, what the heck!!
StirCrazy
10-06-2003, 05:07 AM
hmmm what is the result you want? a lower flow or a difused flow?

Steve
AJ_77
10-06-2003, 05:13 AM
Less flow, Steve. The 1000 is in between a 900 and 1200 - I think it says 265 GPH on it... 230 would be better.

Cavitation? :eek:
Canadian Man
10-06-2003, 05:15 AM
Have you tried putting one of those flow difusers on the end of the pump Alan?
StirCrazy
10-06-2003, 05:19 AM
if you just want it not to blow so hard at your corals you can make a home made difuser like I made for mine wich makes it produce a gental flow.

Steve
AJ_77
10-06-2003, 05:22 AM
Got the MJ diffuser on, but its help is minimal. Less flow is what I want from this thing. Tried a few combinations, positions, etc to see what might work, but it's only a 3-ft tank and the rate is a little too much. The turbulence where it jets into the flow of the opposing 900 is good, lots of churning and water motion around the upper middle of the tank, but it creates one of those currents that is unbalanced to one side, and the LTA's tentacles are all in one direction. it is crawling further under a large rock...

Steve - what is this wonderful device you made??
StirCrazy
10-06-2003, 05:29 AM
I made a difuser that slips over a Maxijet and creats a wider gentler flow.

here are a couple pics
http://members.shaw.ca/s.l.s/diy/slides/Difuse_installed.html

http://members.shaw.ca/s.l.s/diy/slides/Difuse_front.html

Steve[/url]
AJ_77
10-06-2003, 05:33 AM
That's RIGHT - there was a thread with this unit in it, too right? Cool, but how did you do it - or do you ship? :biggrin: Could use one of them puppies...

Is it pretty straightforward to make?

And thanks.
StirCrazy
10-06-2003, 05:36 AM
pritty simple.. i will have to try find the pieces again so I can tell you though. give me a day or to.

Steve
AJ_77
10-06-2003, 05:38 AM
OK thanks - just read that old thread from December of last year - you never did post the instructions, Steve... :mrgreen:

Looks like we might have a winner. I wonder how Victor made his?
StirCrazy
10-06-2003, 05:42 AM
I know it uses a 1/2" plug but you have to find the kind that has a hollow end. only this one fits nice over the end of the maxijet. then there is a 1/2" to 1" bushing I think.

Steve
Chad
10-06-2003, 06:09 AM
OK, I did this "modification" for my MJ1200 to work on my Sea Clone Skimmer.. The problem was.. way to much flow.. so I took the old air diffiuser and litteraly inserted it into the intake. this reduced the flow wonderfuly.. however you need to use the output tube to do this. Not sure if this would work for your application.. I can see if I can get pictures if you like..


Chad
AJ_77
10-06-2003, 07:50 PM
Did your mod preclude the use of the intake screen? I still want to use that...

Can't really picture what you describe.
Chad
10-06-2003, 07:51 PM
Did your mod preclude the use of the intake screen? I still want to use that...

Can't really picture what you describe.

Yes it still uses the intake screen.. it looks really good.. I will take a picture and post it for you.

Chad