I have a 65g (36 x 24 x 18) with built in glassbox overflow with 2 11/2 inch drains and then 2 returns at the top left and right or at least that's what I think the terminology would be.  If its not understandable, let me know and I'll try to describe it better.  Anyway, I was thinking to add 2 vortech mp40w one on the right and one on the left side-- and that I needed to run the water level lower to allow for the wave crest?  If so, does anyone know what level to keep the water at, i.e. 2" down from top or are the vortechs something that I should leave to a different tank given the overflow? 

Thanks.

I just put a Vortech MP40 W in my 90 gallon.  Just one pump creates about 1/2 inch wave.  I'm conviced the remote has a brain, but I must admit frequent referencing of the users manual to enjoy all the benefits this awesome piece of equipment has to offer.  Not sure this answers your question, but I'm not sure you'll need 2 of these pumps for a tank that size.  If you haven't already bought them, you may want to start with just one. 

It's tough to comment on your specific setup, but, I'll bet one would be fine in a 65. I couldn't get much of an organized wave in my 120 with the one I had. I do think it makes a big difference what kind of obstructions you have in the tank... I switched to 2 Tunze 6100s with an AquaSurf and can muster a 1" wave. IMO the wave by itself doesn't provide enough flow.

I'm actually not interested in creating a wave, just to have it look "cool".  To me, it sounds like an accident waiting to happen and I'm at work a lot, which is why I do not want to have a bunch of holes drilled.  I'm looking to create flow in this rimless without a bunch of powerheads.  I looked at other people with a rimless and they seemed to have these vortechs.  I watched youtube videos and it seemed to create a bunch of flow, but I couldn't tell if the wave would cause problems with the overflow, i.e did you have to do some calculations to run them both or could I just slam it in there.    I may just have to purchase one and try it.  I think I'll also look at the tunzes and perhaps, just higher gph on the regular powerheads.  Thanks for the virtual peek into your tanks -- appreciate it.