Technical
“
If you’re planning to ‘do-it-yourself’, you’ll need to consider the
method of securing and the quality of materials used, as these may impact safety, security and ease of service
System installation
There are two ways of securing most units into position ‐ anchoring to the pond bottom, and mooring to the pond’s edges, either above or beneath the waterline. If you’re planning to ‘do‐it‐yourself’, you’ll need to consider the method of securing and the quality of materials used, as these may impact safety, security and ease of service.
When it comes to the tools and materials you need, make sure you have a shovel to bury/trench cable, conduit, stainless steel cable or nylon rope, cinder blocks, boat when anchoring and rebar or duckbill anchors when mooring. Diffused air systems do not require anchoring or mooring, but a boat is often required during installation. Intensive landscaping around the pond, such as retaining walls, waterfalls, and planting beds, could affect the installation process, in addition to the future access for service or maintenance. Further coordination may be needed between the aeration installer and/or irrigation contractor in these circumstances.
Single phase vs. three phase power
Water quality management, beauty, pricing, product quality and warranty serve as primary factors when purchasing an aeration system. But power is a key, but often overlooked, factor.
Power comes in either single or three phase; each type possesses its own advantages.
Single-phase
Single‐phase (see figure 1a) is more widely available in residential settings and is less expensive to purchase than three phase power units. Single‐phase is commonly called ‘residential voltage’ and relies on two‐ wire conductors to distribute power to create a single sine wave (low voltage).
122 I PC JUNE/JULY 2018
Single‐phase summed up:
• Motors are driven by pulsating torque (like a pulsating shower head)
• Motors require capacitors and/or start switches that need to be monitored
• Experiences more interruptions in electrical flow
• Motors have a shorter lifespan Three-phase
Three‐phase power (see figure 1b) is most commonly used at commercial/professional sites and is recommended for larger ponds and lakes. These units are less expensive to operate than single‐phase power units. Units with this type of power only come in 3hp or higher. Three‐phase power relies on three coils mounted on the rotor at 120 degree intervals, which produce three sine wave voltages (high voltage). It’s used universally for power distribution.
Three‐phase summed up:
• Has a smooth and continuous flow of power
• Allows for longer cord lengths/cable runs
• Three phase power isn't available at all locations
• Costs can be higher when installing three‐ phase power
• Units are more efficient to run, but more expensive to purchase
• Motors may experience rotation issues if installed incorrectly
• Motors are generally more efficient. Some convert 97 percent of electrical energy into useable mechanical energy
• Motors have a longer lifespan
When it comes down to it, which is better depends on: what power source is available at the site and the type of unit being
installed. Single‐phase is best used with fractional or low horsepower units (less than 5hp) at residential sites and small ponds; while three‐phase is best used with any high horsepower unit (5hp or more) at commercial/professional sites or larger water bodies.
Diffused air systems create a difference
There’s a simple solution to keep ponds and lakes clean and clear without the use of chemicals and without the need of motorised mechanisms. This solution is the often‐overlooked diffused air system. Fine‐bubble diffused air systems first became popular in the 1970s and have since created a topic of wide debate over the aptitude of their effectiveness. Whilst it has been proven that, in less than six feet of water, diffused air systems are not as effective as other types of aerators, research has shown that, if placed accurately, diffused aerators can be very effective in maintaining a deep body of water. They can also be beneficial in ridding a pond or lake from symptoms of oxygen depletion such as odour, discolouration, excessive algae, and fish kills.
The success of the diffused air system is held in its simple design. Each system comes equipped with three main components; an air compressor, an air hose, and a diffuser. The diffuser is placed on the floor of the pond after being attached to the air hose, which is fixed to the air compressor. The air compressor is located on‐shore and also houses the electric motor. The compressor pushes large amounts of air through the hose and, as the compressed air is squeezed through the diffuser, the result is thousands of air bubbles scrambling at an approximate rate of 1ft (30cm) per second from the bottom of the lake to the surface. In this instance, the bubbles not only transfer the bottom water to the top,
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156
