Learn About Aquaculture
HERE YOU CAN LEARN ABOUT ALL ASPECTS OF AQUACULTURE
You know how you can tell what people know by the questions they ask? Well, we know that most people don’t know about watts. They ask, "How many amps does this motor use?" instead of, "How many watts does this motor use?" Watts are what you pay for, not amps (amps are used to size breakers, etc.).
The direct current formula we all learned (volts x amps = watts) is correct for incandescent light bulbs and electric heaters, but it is not correct for motors. When dealing with power loads that involve inductance magnetic devices such as motor windings, solenoids, transformers, lamp ballasts, etc., the formula for single-phase loads is volts x amps x power factor = watts.
In many cases, especially with linear air compressors and mag drive pumps, the actual watts used are significantly less than what is calculated by multiplying volts x amps. The only way to determine the watt consumption of a motor is to test it using a wattmeter (such as our KW4). In the Pentair AES catalog, we have published the actual watts for most of our motor-driven devices as tested in our RDTE shop with our wattmeter.
Sweetwater® models AQ3, AQ5, AQ7, AQ73, AQ9 & AQ93
DO NOT REMOVE THE ROTOR OR LOOSEN ANY OF THE ELECTRIC MOTOR-THROUGH BOLTS.
We recommend carbon vane replacement at nine-month intervals to ensure trouble-free operation of your compressor. The following tools are required: 3/8" or 7/16" socket/wrench, small hammer and antiseize compound.
- Remove the two end caps from the front of the muffler box (if applicable) and the five muffler box bolts, being careful not to damage the gasket. If the gasket is torn, scrape it off with a sharp knife and replace.
- Tap the box with a small hammer to loosen it. Do not pry with a screwdriver.
- Remove the six bolts holding the end plate to the body. Remove the end plate. Do not remove the rotor or loosen any of the electric motor through bolts.
- Check that vanes are moving freely in and out of vane slots. Replace any vane if more than 50% extends past the vane slot. Top clearance (between rotor and body) may be adjusted by loosening body bolts and lightly tapping on the compressor body while turning the rotor. About .004 inch—the thickness of a sheet of paper—works well.
- Remove vanes and clean both sides with fine emery cloth. Clean the end plate with fine emery cloth.
- Flush vanes, body, rotor and end plate with solvent (part no. AQ255), and remove all solvent from each part.
- Check the body, rotor and end plate for scoring. If each part is clean and shows no signs of scoring, reinstall parts. If scoring is present, replace with new part(s) or contact Pentair Aquatic Eco-Systems for service.
- Insert new vanes.
Reassemble by reversing the previous directions. We always recommend using an antiseize lubricant on each bolt to ensure its easy removal for the next vane replacement. Bolts should be reinstalled and tightened in a similar manner to replacing the lug nuts on a vehicle wheel. Start with one bolt and move to the right, skipping one and tightening the next.
When reinstalling the muffler box (if applicable), be certain to install the center bolt first to ensure proper gasket alignment. Before replacing the muffler box, plug your compressor in for a quick sound check of the valve rotation. If an unusual sound or stopping of the rotor takes place, disconnect and recheck the vane replacement.
If you have any problems, contact Pentair Aquatic Eco-Systems at 877-347-4788 for assistance.
Cost is one of the biggest considerations. This generalized chart should help to quantify the difference between using an air blower with diffusers and using pure oxygen with a water pump and oxygen saturator (oxygen cone). Also see "Oxygen or Aeration" Tech Talk.
THIS GENERALIZED CHART IS BASED ON:
- Electric Cost of 8¢ per KWH,
- Sweetwater® Standard Diffusers at 40" H2O,
- Water Temperature 80°F (27°C) Sea Level,
- Fresh Water @ 24 lb/day Oxygen Concentrator,
- 40 gpm Pump Using 5 Amps @ 115V.
This cost comparison illustrates that blowers are more efficient at lower D.O. saturation values and pure oxygen is more efficient at higher D.O. saturation values. Note that the cost of adding pure oxygen remains almost the same until reaching higher super saturation levels, then pumping pressures and, therefore, cost goes up.
Aspirators and agitators are the aeration devices most commonly used on hauling tanks when the stocking densities do not require the use of pure oxygen. Agitators use a small motor (normally 12V) to spin a paddle which is in the water. The paddle splashes the water, which adds oxygen and removes carbon dioxide. Aspirators also use a small motor, which spins a small venturi device. Air is pulled down through the shaft and exits the venturi underwater, causing a draft of bubbles. Agitators are the best choice for heavy stocking loads because they transfer more oxygen than aspirators. Aspirators are a good choice for smaller stocking densities, and they are much quieter than agitators.