Beware of the continuous siphon, wier type design, <eg CPR>. They have a tendency for air to collect in the siphon & you must use a small pump to evacuate the air in the siphon or you will flood.
I have a DIY version of the wier design, and siphon break is a constant problem. <Others have reported same with this design.> Switched to siphon tubes (like the Eshopps), no problems since.
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.