Following on from part 1 of this article, I’ll continue to look at pumps and water movement by examining energy efficient ways of achieving increased flow and of generating surge or wave movement.
Fancy increasing your water flow for no additional energy cost? Well then, try using an Eductor.
This is a special form of nozzle that can increase the flow rate of a given pump by a factor of 4 through the use of a venturi effect. At the same time the Eductor also modifies the pattern of water flow, spreading the flow making it more suited to reef organisms, much in the way that a Koralia pump does.
For best results with an Eductor it should be used with a high-pressure pump, in aquarium terms the higher the Q max of the pump the better. I wouldn’t recommend use on anything less than a 1200 litre per hour pump. It can be used directly attached to a pump in the aquarium or as a nozzle used in conjunction with a plumbed in system.
Note: many Koralia style pumps impart a rotational component to the water flow as a result of the flow being generated by a screw type impellor of the type used to propel model boats. This form of flow is not commonly found in the wild. The design of the Koralia impellor minimises this effect, while an Eductor imparts no rotation to the flow at all.
Mechanically Generated Surge.
A very cost effective way of improving your water movement is to employ some form of mechanically generated surge such as a SCWD or Hydor Flo.
The SCWD is a water switching or current generating device, best described as being a tee piece on steroids, water is fed into the bottom of the tee by a pump and is then directed alternately out of the two outlet ports giving a surge effect. The higher the volume of water flowing through the SCWD, the faster the switching response.
The Hydor Flo is best described as a rotating water deflector. It fits directly on the outlet nozzle of a powerhead style pump, such as a Hydor Pico evolution. The water flow from the pump makes the Flo rotate and, as the outlet of the Flo is off centre, this constantly changes the direction of the water flow, creating a surge effect.
This is a useful inexpensive device for adding an element of surge in even the smallest reef aquaria.
The beauty of both these devices is that no additional electricity is required to generate beneficial water movement and they have none of the disadvantages associated with mains voltage pumps being turned on and off to create surge.
Closed- Loop Systems.
It’s not just the electricity consumption in generating water movement that is a concern, there’s also the heat transferred to the water by the pumps employed. Getting rid of excess heat in the reef aquarium can be an expensive process, both in terms of purchasing equipment such as chillers and air conditioners and in the electricity costs of running them. If you take the pumps out of the water less heat gets passed on to the aquarium water so there’s less requirement for cooling the system.
So instead of having lots of pumps cluttering up your reef (and your power outlets) why no try using a larger more powerful pump, such as a Hydor Seltz, outside the aquarium, which is dedicated to water movement. This pump just sucks water out and then returns it to the reef to generate water movement, a closed–loop system. It’s quite possible that by choosing the right pump you might actually be consuming less electricity than if you were to use multiple pumps in the aquarium.
Your closed-loop can be made even more effective by running it in conjunction with a SCWD plus eductors as you’ll increase water flow and gain surge at the same time. All with less visible equipment in your reef.
Low Voltage versus Mains Voltage Surge Systems.
The majority of wave makers or surge systems employing mains voltage have the disadvantage of long term damage to pumps and impellors resulting in shorter pump life.
By using a low voltage surge system, such as the Hydor Koralia Wavemaker 2, long pump life is assured along with the advantage of a modern pump with low energy consumption. Additional advantages are the many different settings possible with electronic control: alternate flow, synchronous flow, surge periods of anywhere between 2 seconds and 6 hours, low flow night mode (automatic with the use of a photocell or manual), and low flow when feeding at the touch of a button.
You can get more flow, delivered in a far better manner, by modifying an existing Maxi-Jet pump with a Sure Flow 1600 Maxi-Jet Upgrade Kit. This modifies any Maxi-Jet 400, 600, 900, or 1200 into a Koralia style pump delivering a massive 6000 litres an hour!
The Sure Flow 1600 Kit is made up of a Shroud with a built in anti-vortex shield (see note above, under eductors), a full rotation bracket (designed for use with a Sure Grip magnetic powerhead holder), a medium flow propeller with impeller magnet plus Stainless Steel shaft and end caps, and an adapter bracket to attach the original Maxi-Jet brackets to the full rotation bracket.
It works very well with Sure Grip magnet holders, indeed you can mount two modified Maxi-Jets off of one Sure Grip magnetic powerhead holder.
So. if you’ve got some of the ubiquitous Maxi-Jets lying around in your bits box this is a very cost effective way of getting Koralia performance on the cheap.
Any questions or comments, please feel free to get in touch with me: email@example.com