The tidepool is a wier type overflow. To start the siphon, you can place an airline hose in the wier, tilt the overflow so the airline is at the highest point of the wier & suck out all the air.
From reading the forums, people have problem with air collecting in the wier type overflow because of low flow velocity. It is generally recommended to use a small PH or Venturi to continuously remove air & maintain siphon.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.