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It ain't pretty, but this DIY Wavemaker provides a 3-4 gallon flush of water that lasts about 10 seconds.  With a big enough pump it will refill in about 30 seconds.  It's simple and passive, and my anemone and gorgonian seem to love the output.

Principle

  • This wave maker is based on a simple siphon flush mechanism and uses a 5 gallon plastic bucket and commonly available PVC parts.  The only specialty item is the bulkhead fitting, which you can get at many mail order pet supply houses.
  • Water is pumped into the bucket by a powerhead or pump.  I use a branch of my sump return (rated at 2400gph).  A strong powerhead also worked (when used to push water from the tank), but the wave effect was slower to cycle.
  • When water reaches the U of the drain tube, a siphon is formed, sucking water through the 1.5" PVC pipe.  This outflow is directed as desired.

Click this link to see a low-res video of the wave action.


Assembly

The assembly of this wave maker is basic.

  1. You need to cut or drill a hole in the bottom of the bucket that will accommodate the 1.5" bulkhead fitting.  You then attach the bulkhead fitting.
  2. Then assemble the U.  This is made with two 90-degree 1.5" elbows butted closely with a short section of 1.5" PVC pipe and then solvent welded.
  3. After you assemble the U you need to size the "legs" of the U.  The first leg extends from the bulkhead fitting to the bend.  The top of the U should be a MINIMUM of 1" below the rim of the bucket.  This is a safety margin to prevent overflow.
  4. The next leg extends from the U towards the bottom of the bucket, and leaves a small space for water to flow.  When you get the lengths right, fit (but don't weld yet!) the U together and take your project to bath tub or sink.
  5. Fit a scrap piece of 1.5" PVC pipe to the other end of the bulkhead fitting (the part outside the bucket), and stand the bucket on the tub with the scrap tube emptying into the tub.
  6. Fill the bucket slowly, preferably using the same pump you will be using in the working setup.  As the water gets to the U, the siphon should begin.  Now is the time to troubleshoot.  If your pump is too slow, you may find that the siphon never gets to the point that it whooshes out.  The only solution for this is to get a larger pump (or start again with a smaller siphon pipe.  If your pump is too fast, you may find that the bucket overflows.  You need to cut down the flow on the pump, or increase the distance between the top of the U and the rim of the bucket.
  7. Once everything seems to be working fine, you can then put the bucket in an elevated area above your tank and finish the plumbing.  Remember that 5 gallons of water weighs about 50 pounds, so choose a sturdy support.


Drawbacks

This wave maker does introduce large bubbles into the tank.  I have not found a way around this.  However, the bubbles are large enough that they rise to the surface quickly.  I do not keep sponges, which I understand do not tolerate contact with air.  My anemones, gorgonian, and mushrooms seem to THRIVE in this outflow though.

The wave maker is also noisy.  I wish I could say that it sounds like the crash of the surf on the beach, but to be frank it sounds more like a flushing toilet towards the end of the cycle.