Hydor mod with tunze impeller

[Chin_Lee]

Just thought I would throw it out here.
Background:
I have a Hydor Korallia 2 and 3 in my LPS tank but found their flow a little too low.
I had a broken tunze drive unit from a tunze powerhead so I salvaged the impellers.
I had some spare MJ1200 powerheads.

Modification:
So I don't take credit for this idea, I made this mod after following this thread for a few months:
http://www.reefcentral.com/forums/sh...5&pagenumber=1

step 1 - I took the white impeller off the MJ drive unit.
step 2 - I increased the hole size in the base of the tunze impeller to 15/64. I only drilled into the base about 3/8" so I didn't need to drill through the entire impeller. Push the impeller onto the MJ drive unit and you will find the notches on the MJ drive unit will fit into the cut-out notches on the tunze impeller
step 3 - trim and cut the tunze impeller until it can fit into the korallia without touching the edges
step 4 - try not to do this step -i broke the ceramic drive shaft by not aligning the ends to the holes before trying to put the front end on the korallia. Luckily I had some highest grade 316 stainless steel rods of the same diameter. (I bought these when I planned to make a bunch of MJ mod impellers so if you break your ceramic shaft on your korallia, PM me) I cut them to length and grinded down the ends until they are the exact length (i believe it was 91mm for the HK3)

The MJ magnets fit into the hydor powerheads. I put the tunze impeller mod into the HK3 and I put the original HK3 impeller into the HK2.

Observations:
My modified HK3 is now a HK6! Flow is easily doubled if not more.
My HK2 is now a HK3.

Future mods:
I'm planning to get some HK4 and put in different Dumas propellers for mods.
I prefer the HK units for mods instead of the MJ because the housing is so much more attractive.

Now I have a Hydor Korallia 3 and 6

[albert_dao]

Hmmm, I'd love to see how much energy that baby draws