need help with diy overflow box. Curruently put together overflow box with 2 lee's specimen containers. 1.skimmer box in tank. 2. hang on outside tank. 15 gal sump 5gal bucket filter. Using 3/4 in cpvc pipe & elbows as my siphon tube. However, i cannot get the water to siphon from tank to overflow box. any suggestions on how to get it going. I'm about to pull my hair out about this.

