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| Raceway- pump,air,water movement. Best practice ideas http://byap.backyardmagazines.com/forum/viewtopic.php?f=1&t=4315 |
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| Author: | DanDMan [ Oct 15th, '08, 05:24 ] |
| Post subject: | Raceway- pump,air,water movement. Best practice ideas |
Ok, Im am looking at building a small raceway and have some questions I wanted to throw out to fish for some ideas of what the best practice is for operating a race way. -Method, Flood and fill from pond elevated grow bed, no sump -Proposed water volume 5000 gallons / 18927 liter raceway. -GrowBed volume 8000 gallons / 30283 liter -Stock Density, ~ 1000 fish -Solids settling area before pump to growbed to optionallt remove solids. -Air via returning water and air pump or paddle wheel -Water pump, Electric start diesel water pump, electric pump, or other method -Water Volume in Race when grow bed is flooded 2668 gallons /10099 liters (Based on Small brown river pea gravel displacing 66% of water) I want this system to be as efficient as possible so here are the questions I am "thinking on" and would like input on. 1) should I pump water around the raceway, or pump from one end and return grow bed water to other end? 2) Should I use a paddle wheel? 3) Should I use Air stones? 4) What pump is best suited for 2 to 3 foot lift? Perhaps a water bucket wheel that lifts the water up to a tray that brings the water down to the grow bed? I am thinking a lifting water wheel to lift water, and a paddle to keep flow in raceway all powered from a single motor. Input? Suggestions? Experience? Opinions? |
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| Author: | Uncle Yarra [ Oct 15th, '08, 05:48 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
I climbed over the fence near the Cotter dam in Canberra to sneak a peek at the old trout farm. The raceway has a lot of corrugations in it and also has a waterfall-type drop into each tank. If it's enough oxygenation for trout.... Sorry, no pictures. |
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| Author: | Outbackozzie [ Oct 15th, '08, 06:00 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
1. pump from one end and return grow bed water to other end. 2. Dont think it would be required. 3. As above, your stocking density will be extremely low, however they should be used as a back up in case of pump failure. 4. Your talking about a heck of a lot of flow, I dont think a bucket wheel will cut it. This is a very large idea, and is going to need a decent sized pump to circulate the water to such large growbeds. Ideally you will want to turn at least 5000 litres of water over per hour for that amount of fish, this can be done with around a 100 watt pump. Personally I'd get the biggest pump I could afford to run. A diesel pump does not even enter the equation. |
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| Author: | mylesau [ Oct 15th, '08, 08:22 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
If you haven't already seen this: In-pond raceway, it might give you some ideas. Not exactly what you want, but food for thought... I'm sure there will be someone who doesn't like the idea...  I was going to put in a waterwheel, but decided that it would probably lead to a fairly high water evaporation rate so have shelved that idea for now. |
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| Author: | hygicell [ Oct 15th, '08, 08:42 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
dividing your growbed in sections and filling/draining them in sequence would allow for much less level variation in the fish tank with a cross section of 1 m² your fish tank will be 19 meters long and you will have 40 m² of exterior tank surface you will then also need a 19 m long pipe or gutter to bring the water to the other end you could make a U-type raceway (with a divider in the middle) with a cross section of 2 m² which allows you to halve that length and reduce the outer surface to 23 m² and reduce all piping lengths to say 1 meter A W-type raceway (three dividers) with a cross section of 4 m² would further reduce outside surface to 17.5 m². alo the footprint will be much less should you think of a greenhouse over it Outside tank surface is expensive as it must resist water pressure dividers are under no pressure at all and can be cheap less outside surface means less temperature losses, more temperature stability but you speak of an in-ground tank, I believe? the bigger your (centrifugal) pump, the better chance you stand of finding an energy efficient one the pump OBO suggests (5000 litres @ 1 m head) has an energy efficiency of 14%, which is to be considered as reasonably good as far as small centrifugal pumps go. a water bucket wheel if well designed will be MUCH more efficient as it is a positive displacement pump with the right motor, energy efficiency of 80 to 90 % can be reached I have a very low opinion on air stones and airlift pumps, but will not repeat it here as this raises the hairs of some members and I have no mood for another discussion on the subject. Just do a search on "diffusers frank" to view it. maybe make a sketchup drawing of your proposed setup? mylesau wrote: If you haven't already seen this: In-pond raceway, it might give you some ideas. most interesting link, Mylesau, thanks for it I like the idea VERY much frank |
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| Author: | Sleepe [ Oct 15th, '08, 08:55 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Frank designed a rather interesting passive oxygenator, its in the sketchup components (not sure if he's tested it yet). If you pumped from one end of the raceway to the GBS and returned to the other end via the oxygenator you would only require one pump (to the GB's). To make it efficient you would probably have to have the GBs along one side of the raceway (or both if your going bigger  ) and do a 90 degree passive oxygenator for the return (not a biggie more DO).Biggest problem I could see is getting the drop (for the F&D) then having sufficient drop for the oxygenator. |
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| Author: | RupertofOZ [ Oct 15th, '08, 11:17 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Actually that "Pond in Raceway" link would seem quite simple to implement... and has oxygenation and solids settling built into the design.... Uses a series of airlifts for oxygenation and flow dispersal... quite "effective" ... even if not "efficient" .... 
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| Author: | Sleepe [ Oct 15th, '08, 12:34 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Still got the problem of the lift required by Dan, that was 2-3 feet. |
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| Author: | RupertofOZ [ Oct 15th, '08, 12:40 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Thought that was all Dan needed ... 2-3 feet... 
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| Author: | Sleepe [ Oct 15th, '08, 13:03 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Rupe Unless I read that wrong they are using the airlifts to move and oxygenate the water not to lift it. |
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| Author: | RupertofOZ [ Oct 15th, '08, 13:35 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Way I read it Sleepe ... it does all those things.... but in fact it it "the pump" as well... No other pumping mechanism indicated in the text or drawings .... On page four of the mentioned article it is wrote: Air-lift pumps
Air-lifts provide a simple and efficient (  ) means of moving large volumes of water. Rising air bubblesinside an air-lift’s tube act like apiston pushing water above it.However, this is efficient only if the water is lifted a small height above the surface. In fact, mostair-lifts will not lift water over 3 or 4 inches above the water’s surface. Air-lifts work most efficiently when they are releasing water at or very near the surface. A single 3-inch air-lift discharging at the surface will move between 50 and 60 gallons per minute if built as described below.... Air-lifts have the added benefit of aerating incoming water when dissolved oxygen (DO) concentrations are much below saturation.... In research trials, when pond DO fell below 2 mg/L the DO in the IPRs has been maintained at 3 mg/L even with high biomass. Because of the mixing action of water and air in the air-lifts, supersaturation is virtually eliminated |
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| Author: | Sleepe [ Oct 15th, '08, 14:00 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Page 2 "One of the most common IPRs has been built of treated plywood, framed with treated 2x4 lumber or steel, and coated with epoxy paint. Sizes have been either 16 or 24 feet long, 4 feet wide, by 4 feet deep (only 3 feet underwater)." While they state they float, I think they mean they just float. |
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| Author: | Food&Fish [ Oct 15th, '08, 14:06 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Has anybody thought if useing ap water you would have to keep it covered otherwise it woud go green slimey |
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| Author: | hygicell [ Oct 15th, '08, 16:26 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Sleepe wrote: Frank designed a rather interesting passive oxygenator, its in the sketchup components (not sure if he's tested it yet). If you pumped from one end of the raceway to the GBS and returned to the other end via the oxygenator you would only require one pump (to the GB's). To make it efficient you would probably have to have the GBs along one side of the raceway (or both if your going bigger ) and do a 90 degree passive oxygenator for the return (not a biggie more DO).Biggest problem I could see is getting the drop (for the F&D) then having sufficient drop for the oxygenator. the passive oxygenator in the drawing is only 100 x 100 mm in cross section (so only needs a drop of 10 cm) but it can be made to whatever size I will test it later this week for functioning, but will not be able to prove anything with hard data as I don't have a DO meter I will take a picture of the water flow before and after, maybe that will show a difference the in-pond raceways don't float on the water, they float in the water there is no head to cope with that brings up maybe a "novel" idea for moving around the water in the raceway: how about a "trolling" outboard motor used to power fishing ? 12 V battery powered http://www.minnkotamotors.com/products/ ... .asp?lp=gb installing it in front of a pipe might even give you the necessary head then it would become a propeller pump which are considered as very efficient or installing a smaller pipe in front of it might lead part of the water to the growbeds frank |
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| Author: | Sleepe [ Oct 15th, '08, 20:41 ] |
| Post subject: | Re: Raceway- pump,air,water movement. Best practice ideas |
Stick a simple flute on the ends of the venturi and you may have invented a 'wind chime for' AP.  BTW "the in-pond raceways don't float on the water, they float in the water"? |
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