You are welcome over at any time Keri :biggrin: ... cant explain any better how it works but seeing is believing :eek:

Cheers

Kari, ok all the flow from the pump through the eductor still goes throught it, but instead of using it as just water movement they use that flow to create a "venturi" effect. this will pull "extra" water in from the sides and also cause it to move along with the stream, so in essence you are moving more water. the same effect is used to pump water and other fluids except the eductor would be incased in a housing with a pipe comming off the middle going into the fluid you want to pump. in this case you final fluid movment would be the amount generated by the pump plus the amount moved because of the venturi effect. beckets skimmers work on the same idea, except the second fluid they are pumping is air.

Rasta, did the dealer tell you they woulden't work or woulden't work as designed? they should develop a venture effect even with a little amount, but for my self I was sceptical about how much they would develop with less than the recomended amount of flow. would be interesting if we could figure out some way to measure it befor you get the new pumps so we can see how much of a difference they make.

Steve

When I talked to Ken on the phone before I ordered he was insistent that a pressure rated pump is required I guess because of the back pressure created when the eductor is reduced to 3/8" orifice ? ... he worked it out that a Mak4 with 2 eductors would be more powerfull than with 1 ( 7 PSI with 1 eductor and 6PSI each for 2 eductors ) ... not sure how he came up with the math as he was working from a graph of head loss for that type of pump ... so all I did was put 2 eductors on each of my Mag18's as I would have done with the Mak4's

Does anyone know how to measure the output velocity of a pump ? ... maybe if Jonathon is reading this he can bring over his Mak4 and we can do a quasi-test with Mag18 on one end and Mak4 on the other ?

Cheers

Steve;

Thanks for the notes! I'll have to do the math and see the unit before it makes sense in my head. I didn't think of a venturi. Now I'm way too curious about the magic stuff. Going to look for the dusting text book.


Rasta;

You'll need an adaptable flow meter I figure. Not many of us have one hanging in the garage including myself. I would just compare to with/without using the old eyeball guage.

Food coloring in the water. Confetti :lol:

I could bring over the mak pump steve. It just means that I have to shut my skimmer down for a while which is no biggie.

cheers

food colouring would give the best visual indacation of flow but might be a pain in a reef tank as you would have tyo get it all out befor the second test :mrgreen:

Steve