$100 - $225. But you won't get the head pressure of the RD's by modding them.

I believe the volute is also modified to accomodate the PF4 mesh

That and the increased airflow. Keep in mind that Hahn's mods were geared towards producing a GREAT skimmer pump, not a GREAT return pump, which the RD's are.

Albert thank you for posting these pictures.
Klaus was kind enough to send us some pictures from Royal-exclusive factory In Colonge Germany.
I will ask Klaus again in regards to the similarities of the 2 pumps ,but I can assure you that they are not the same,Albert is right about the skimmer pump & RD difference & also thse are the new generation RD & the new ocean simulators that will hit the market by the end of september.
http://i28.photobucket.com/albums/c220/reeftec/rd2.jpg
http://i28.photobucket.com/albums/c220/reeftec/rd3.jpg
http://i28.photobucket.com/albums/c220/reeftec/rd4.jpg
http://i28.photobucket.com/albums/c2...ftec/rd4-1.jpg
http://i28.photobucket.com/albums/c220/reeftec/rd5.jpg
http://i28.photobucket.com/albums/c220/reeftec/rd6.jpg
http://i28.photobucket.com/albums/c220/reeftec/rd7.jpg
You can see the different motor blocks being tested for a log time here also,tested in hotwater ,SW,also you can see the dimmable reddragon brushless,DC pump with the controller ,We will be showing these products @ MACNA ,the dimmable pumps are what we really excited about ,I will try to get a couple of pictures of different cross current wave designs in German Tanks using this system.
Regards
Jason

This is my own tank I am in the process of setting up ,
In the bottom picture you will see the 2 holes which will be used as an intake for an RDII pump ,the pumps will be dimmed @ opposite so
pump A 100% -------pump B 0%
pump A 0%--------pump B 100%
so you will create suction out of different holes in different amounts in a set period.
The holes on the overflow pane will be used as the output in a cross patteren,so the one line will blow the other @ 0 & vice versa.
This will eliminate the need for any Oceanmotions,Wave box & other methods ,the currents changes are alot more gentle & also the current will become less directional & more irregular

The, uhhh, jealousy factor is like x100234 on my end right now Jason...

Don't Worry Al,the price is not going to be as bad as you think ,ofcourse more than other products but does the job of a few streams & wave boxes,I believe the smallest RDII pushes something more than 5000gal/hr .
It's an inovative approach IMHO,which makes it interesting ,I will keep you posted once I get the tank.:mrgreen:

Oh, how come the holes are so small in that tank man?

Are you talking about the exit holes?
Originally was thinking 4x3/4" but the final design was changed to 4x 1",& the Intakes are 2.5" each . so I think that should be fine considering the union on the RDII I had in mind will work fine with 1.5" but we will use a reducer from
2.5" to 1.5"on each intake.