The Amazing Surg-o-matic

[Peter]

As part of my water return system, I use a simple surger device to create water motion within the aquarium. Surgers are interesting since unlike powerheads, pumps, and wave generators which all created water movement, these units create water displacement.

As a result, this establishes a more dynamic type of water motion within a closed system. Water levels rise and fall as water surgers throughout the system creating an ebb and flow to the aquarium. Consequently, a natural rhythm is generated to the reef environment. In addition, surgers are synergistic in that they improve other components of filtration making the entire system greater on the whole. That is, surging has many functions, and is not limited within the main tank only.

For my 65g aquarium, I mounted the surger on the right side of the aquarium, above the tank. This greatly simplifies the plumbing of the surger, especially on the output side. I built an acrylic hood to house the unit.

On the left side of the hood, a 150W, HQI, 10k halide is angularly mounted with a glass splashguard. To get an idea of the incline, the light is about two inches from the water surface on the left side and approximately six inches above on the surger side.

[Peter]

Here is a shot from above showing the surger with the top cover removed. I like this unit since it is fairly compact and effective. Best off, it has no moving parts and thus is extremely reliable. Dump bucket units probably create better surgers, but require more maintenance and are somewhat noisier.

The unit has two chambers, one large, the other small, connected by a large siphon tube. Water is pumped to the large chamber where it fills to a certain level that, in-turn, starts the siphon tube. Water then flows into the smaller chamber and out to the aquarium through three directional ports. However, the siphon flow rate, 375gph, is higher than the flow rate to the larger chamber, 250gph, so eventually the water level lowers to a point where the siphon breaks abruptly, stopping all water flow. From there the whole process begins again as the larger chamber starts to fill-up. This unit surgers for about 12 seconds and is off for around 24 seconds. The actual water displacement is about a gallon or so. This thing just keeps going and going like the little energizer bunny.

The three pieces of thin white tubing are use to vent the output port to create a smoother surge. One of the added benefits of this particular device is it functions as a detritus trap before water enters the main tank. Since the unit has two chambers and a connecting siphon tube, detritus will get trapped and accumulate in the larger, first chamber. Every month or so, I simply remove the entire unit from the hood and wash out the dirt. The unit is then dropped back in the hood and power is restored.

[Peter]

With the halide removed you can see the three directional output ports of the unit located on the far right side of the tank. I would assume the surger rate of 375gph is somewhat equally divided among the three outputs at approximately 125gph each. The outputs are set up so that the farthest port forces water downward across the back glass and behind the rocks to flush out that area. The second and third ports send water across the center and front of the tank, respectively, with the front port delivering the water deeper below the surface.


I cut up ½” clear siphon u-tubes for the output ports. These are much smoother than using elbows and tubing. Along with mounting the outputs above the water surface, this really maximizes the surge as the water breaks the surface and enters the aquarium. This is one part that needs maintenance as algae growth on the ports causes the output surge to become sluggish and ultimately diminished.

[Peter]

Here is a pic of the surger during output flow. Notice the different angles and directions that the water enters the aquarium.

[Peter]

Here is another pic showing the output from a different angle.

[Peter]

This picture from the back of the tank shows the complete hood assembly. I have to clean that glass splashguard every week to remove salt deposits that accumulate from the surging water.

[Peter]

The left side of the tank has a built-in overflow box. The idea was to have the water surge from the right side to the left side of the tank where the overflow is located. This overflow aids in water movement in that it removes water both from the surface and continuously along the top 14 or so inches of water depth around the box.

[Peter]

One added benefit of this type of set-up is its ability of achieving good water movement without the use of any surface mounted powerheads or water pumps.

[Peter]

The surger does not provide all of the water flow. There is a continuous water flow generated by the outputs of the refugium and in-line chiller. The two PVC pipes located in the center of the tank provide the output flow directly into the main tank by-passing the surger (do not pass go, do not collect 200 dollars ). So, you can think of the overall flow as a continuous steady flow, augmented by the periodic wave, or water displacement, of the surger. The continuous output is 200gph, divided among 50gph for the refugium and 150gph for the chiller. Total water flow rate is 450gph, with again, 250gph coming from the surger, delivered at the rate of 375gph.


The center brace on the tank was modified with a piece of clear acrylic to eliminate the shadow created by the halide mounted above.

[Peter]

Here’s the small, 2.5g refugium (which some like to refer to as the dirty tank ), with gravity-powered overflow. The union ball valve below controls the flow rate to the tank. Just some rocks, macro, and a whole lot of critters.

[Peter]

This in-line chiller/heater controls system temperature with a digital thermostat and thermometer. Flow-through units are accurate, but a bit temperamental. Anyone thinking of using these units should understand that flow rate is critical to proper operation. These types of units are designed and calibrated to a specific rate of flow of water. Thats why, in response, I use a separate dedicated return line for the unit. Another union valve is used in this line to set the flow rate. I think for this unit it should be anywhere from 125 to 175gph.

You also have to clean the unit periodically and make sure the area around the unit is properly ventilated. Otherwise, the chiller will reabsorb the heat that it’s dumping there from the water. I use a small fan located above the sump to keep a constant flow of air around the tank.

[Peter]

Back to the overflow. With a surger some interesting flows occur around the overflow box. What you get is a sort of reverse surge as water is drawn into the overflow at different rates in different directions at different times.

I didn’t plan it this way, but in my case during the steady flow stage all of the water is drawn from below the water surface. It seems the continuous flow is not enough to overcome the surface overflow resistance, given the sub-surface geometry of the overflow box.

Here is a pic of the overflow during continuous flow. The sub-surface overflow is handled by the internal chamber located in the far right corner of the overflow box in this picture. Notice the water along the surface of the box and water level within the overflow. I know, it’s not the best pic, but I’m trying my best here.

[Peter]

Here’s another pic of the overflow during surge. During this phase the sub-surface water extraction increases along with an addition of water flow from the now active surface overflow. If you look closely you will see this in the pic along with the higher water level within the overflow box. Again, not the best pic.

[Peter]

Another interesting aspect of the surger is its effect on a small carbon chamber in the pre-filter. Following mechanical pads the water enters a chamber designed to force, or more accurately encourage, water to pass through it. I place carbon there continuously to remove tannins released from the algae growing in the scrubber. Again, here the surger creates an unusual environment within the chamber. Here is a pic of the chamber during continuous flow. At this time, the chamber is half-full leaving the carbon partially exposed.

[Peter]

During the surge the chamber is rushed with water, which completely submerges the carbon. I talked with my homeboys over in Queens at ESV (Empire State Varnish), and they were kind of mixed about the effect this type of water flow would have on the carbon. In one respect, they felt the periodic flushing of the carbon might increase its efficiency by reducing detritus build-up, which can occur under steady flow conditions.

However, they also felt the partial exposure of the carbon to air would reduce its capabilities and would alternatively promote the growth of nitrifying bacteria. I don’t know it’s probably a little of both. I do know that it appears effective as it removes the green tint of the water, although, that could be solely due to the quality of the carbon. Anyone out there with any ideas on this? Here’s a pic of the chamber during surge.