The SEIOs should give you a large area of flow, like a Tunze, instead of a small concentrated area of flow, like a maxi-jet powerhead. In a 29g, you should see your corals waving around nicely
You can adjust the flow of the SEIOs by twisting the outlet nozzle. There are two tubes in the outlet nozzle, one inside of each other, which both have slots cut into them. To adjust the flow of a SEIO, twist the outside tube of the outlet nozzle to enlarge or reduce the size of the slots of the two tubes.
HTH,
Michael
P.S. - If you have caps on the SEIO outlet nozzles, you should take them off and mount your SEIOs "Tunze-Style" to get the most flow out of them