[bekko]

Quote: Originally Posted by bekko AERATION: pond 12 ft x 50 ft = 0.014 acre 0.014 acre x 16 ponds = 0.22 acres total water surface Anticipate the maximum feeding rate to be 50 lbs/acre/day 50 lb/acre/day x 0.22 acres = 11 lbs/day of feed. You will want to budget 1 lb of supplemental oxygen per lb of feed. 11 lbs feed/day x 1 lb oxygen/lb feed = 11 lb supplemental oxygen/day Oxygen transfer efficiency in shallow ponds from bubble diffusers is only about 0.5% at a ambient oxygen concentration of 3-5 ppm. 11 lbs oxygen/day divided by 0.5% = 2200 lbs/day oxygen passing through bubble diffusers. At 1 lb of oxygen per 60 cubic feet of air, you need 2200 x 60 = 132,000 cu.ft of air per day This is equal to 92 cu.ft/min or 92 cfm. Using the Sweetwater brand of regenerative air blowers, you would need a 1.5 hp unit to deliver 92 cfm at a depth of 3 feet. But, rather than buy a 1.5 hp unit initially, I think you should get a 0.5 hp unit the first year, add a 1.0 hp unit the second year, and another 1.0 hp unit the third year. You will not need to run them all at the same time, but you do need back-up equipment for this critical component of the operation. The 0.5 hp unit draws 471 watts (0.471 kw). Running 24/7 for 10 months of the year, the electricity use will be 0.471 kw x 24 hr/day x 300 days x $0.08/kwh = $271/year Triple that ($831/yr) at full capacity when running 1.5 hp of aeration. WATER DISTRIBUTION: Well Water: Most people would run a water line from the well head along the line of ponds with a tee and valve at the deep end of each pond. You will want the water supply to be at the deep end so it is available at harvest. That is probably a 1.5 PVC pipe. Tell me about the well pump and maximum water output? Pond-to-Pond Transfers: I would suggest you run a second 1.5 inch water line alongside the first - again with a tee and valve at each pond. This line will not be connected to the well pump. If you want to transfer water between ponds, throw a submersible pump into the pond you want to pump from and connect it to the PVC pipe with a length of flex swimming pool hose. Open the valve on the pond you are pumping from and the pond you are pumping to and plug in the pump (on a GFI circuit of course). This will let you move zooplankton from one of the last ponds in the row to one of the first ponds in the row without fussing with yards of hose. Drain: I am not sure of the advantage of having pipes joining adjacent ponds. Most people would put a 4 inch line through the berm at the deep end of each pond. Inside each pond, the 4 inch pipe would have an elbow and a vertical standpipe with a screen which extends up to the water surface. On the outside of the pond, each of these drain lines would connect to a tee and all the tees would be connected to a manifold. If you tilt the standpipes at the elbow in the pond you are pumping from and the pond you are pumping to, water will flow by gravity from one back to the other. -steve hopkins

KFG, you either mis-understood or came up with the pipe between ajoining ponds on your own. I think what we suggested was that you run a drain pipe through the end of each pond and manifold them together. There would be a riser pipe in each pond to control which pond is feeding water to the manifold. The manifold would terminate at the sump or effluent pond or could be closed off with another riser. We also discussed being able to pump water from a pond with heavy zooplankton to a pond with newly-hatched fry. The drain pipes and manifold described above could be used to return water from the fry pond to the zooplankton pond without using a siphon - even if the two ponds in question were at opposite ends of the row.

Use at least 1-1/2 inch pipe for the inlet line from the pump. You will need the larger size eventually, if not immediately.

You can get by with a half-horse air blower to aerate all your new ponds. Electrical cost is about $271/year.

-steve