Hofer Gurgle Buster
(not be be confused with the Pan Galactic Gargle Blaster, the stiffest drink in the universe)

A reef tank inspires the imagination and can add great beauty to any home, so it is no wonder that many reef tank owners keep their tanks in the living room, bedroom, or study, all places often desired quiet at some point during the day.  Unfortunately, a modern reef tank is often not as quiet as the view serene.  Canopy fans, sump fans, ballasts, pumps, and the sound of rushing water can combine making quite a noisy affair.  In most cases, silence can be restored by reducing or eliminating each noise component separately.  The Hofer Gurgle Buster (HGB) is aimed at reducing gurgling in an overflow, external or internal, often times the single greatest contribution of noise.

On the surface, reducing the sound from an overflow is simply a matter of raising the water level in the overflow such that water doesn't fall as far and thus makes less noise.  This can be done with a simple standing pipe, but this solution only works if the flow rate into the pipe is low relative to the full flow potential of the pipe.  If the flow rate approaches a decent fraction of the pipe's potential, the top of the pipe first begins to gurgle and, as the flow is increased, form noisy vortices. Over the years a number of simple do-it-yourself solutions have been devised to address this problem.  Two such popular solutions are the Stockman Standpipe and the Durso Standpipe.  I have tried both of these solutions but have found neither as quiet or reliable as the HGB.  Why?  Here are the problems I encountered with those two solutions:

Stockman Standpipe (SS) Problems

  • Air injection achieved by mixing at the water's surface - this makes for quite a bit of noise inside the standpipe, some of which can be heard.
  • Back pressure is not controlled - in theory this shouldn't matter, but as a result, slower flows tend to be louder than the HGB in my experience.
Durso Standpipe (DS) Problems
  • All the problems above PLUS:
  • Air intake adjustments are sensitive, and if the air hole is too small or salt spray clogs the port, there is a loud flushing.
  • Too large to fit in many overflows
The HGB is largely a derivative of the SS, which is why it rather looks like the SS.  However, the changes make a significant noise reduction for certain flow rates.  Furthermore, my design has been well tested by myself and three other reef tank owners over the course of the last three years in five different reef tanks without a single problem.  In fact I am using the HGB in my current 120 gallon tank in the internal overflows.  So, without further ado, click below to see how to build the HGB.