Collection: Overflows

The Link Between Display and Sump

Your overflow decides where the display's water line sits and how quietly the drain runs. A mismatched one gives you gurgling, a bouncing water level, or a flood if the siphon breaks while the return pump keeps pushing.

Two Approaches

• Hang-on overflow boxes — no drilling required; choose by rated flow so the box comfortably exceeds your return pump's output.
• External overflows — for drilled tanks, mounted outside the display so nothing intrudes on the aquascape.
• Sock holders — hang-on mechanical filtration for systems without a built-in sock chamber.

Always rate the overflow above your pump's real output rather than matching it exactly. If you're running a hang-on box, add a siphon-break alarm or aqualifter. Questions? Email info@jlaquatics.com.