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phri last won the day on August 25 2020

phri had the most liked content!

About phri

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    everything fishy

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  1. If you just want to keep a couple of koi, it will be fine. However I don't think you going to have enough nutrients to grow much plants on the waste. IMO round tanks can look just as good as a raceway, but I am not an expert in WAF. Second hand aquaculture tanks shouldn't be too expensive. Alternative smooth wall round poly rainwater tanks can be used for the fish. Second grade watertanks with imperfections in the top molding can often be found cheap, and you want to cut of the top anyway.
  2. I know my reaction is a bit late, but a saltwater skimmer is not going to do much in a freshwater aquaponic system. The surface tension of the salt water enables the formation of the fine bubbles which makes skimmers work so well. There are some commercial freshwater skimmers but I am not to impressed of their performance.
  3. Just a bit on the design; the raceway setup for the fish is going to need a lot of flow or a lot of cleaning to keep the water quality acceptable. A couple of IBC's for the fish will work better, or even better some round aquaculture tanks. You could install an extra ibc after the fish tank to add some extra filtration as this can reduce the fluctuations of water quality due to changes in biomass of plants.
  4. It might be that the static head & hydraulic head combined is close to the max head of the blower. Single stage ring blowers are design to move a lot of air with very little back pressure. Do you have the pumpcurve (head vs flow) for the blower? Also do you have any restrictions in the suction line? such as air filters/non return valves etc as they can reduce performance substantial. Try to run the blowers in series: one blower outlet connected to the inlet of the next one (you create a 2-stage blower). But be careful that the blowers get enough cooling as the airtemperature will
  5. This instruction video isn't correct. The fishfood should cover the needs of the fish as accurate as possible. Shifting to a lower protein diet (sub-optimal) is going to result in more waste, lower food utilization % (higher FCR), and maybe even compromised fish health, thus this makes no sense to me. IMO better would be lower total feed load, less fish or more plants and/ or secondary nitrate removal. Water replace, dnf etc.. Btw if you stop feeding the organic waste in your system will still be broken down slowly, further bacteria mass will go down too, again with the release of nitrate
  6. And if you take regular weight counts (maybe 1 x every 10 days) you can follow performance of the animals with regards to total biomass, FCR and SGR.
  7. Hi Jake, We did something very similar at Latrobe University (Melbourne Australia) last semester as part of an undergraduate subject. Although the focus was on perceptions of aquaponics. We are in the process of analyzing data and I would be interested in comparing outcomes at a later stage.
  8. Hi Bigdaddy, That's a very neat installation, although I don't like all this expensive equipment fully exposed to the elements. I am running a simular set-up while based in country victoria. Mine is already running for 3.5 years and I still use old style AGM batteries, which approaching end of service life now. I have several aquaculture/aquaponics systems running. The system saved my fish a number of times during a power outage. So it's not just reducing power bills. btw my bills are in the plus during the summer, although the feed-in tariff is not great ($0.12 / kWh), while gridpow
  9. Cecil

    Only if you're interested, if you want to figure out how large a box four of the egg hatching trays would fit into, and a ball park weight, I would be happy to pre-pay shipping plus more to make it worth your while if shipping isn't too high. Most likely whatever shipping is would still be cheaper than buying them brand new. I assume you are talking Marisource or similar egg vertical incubation hatching trays?  Thanks!

    1. phri


      Sorry that's a misunderstanding, I have those horizontal "old style" raceway tanks with hatching trays.

      I don't think shipping is a viable option, these tanks are like 3.5 meter long and build from fiberglass/resin. I am shipping from the us sometimes and the freight is shocking; 3 months ago I paid US $350 for freight for a small adjustable bar grader; viable as none in the country at that time and client had 100,000 fingerlings of a cannibalistic species hammering each other. 

    2. Cecil


      Yes I misunderstood no problem. And yes shipping is crazy for something like that. However I am lucky I can buy the horizontal raceways from a company in Florida USA (Pentair/AES) with free shipping on orders over $50.00. If one has to pay shipping here many times the shipping is just as much or more than the tank! 

  10. I think I would prefer the old style trough tanks, as you actually can see what's going on without opening anything, and thus this will enable you to pick up a problem hopefully before it becomes a disaster. It's a pity you are not closer as I have 4 of those laying around unused including 4 trays each.
  11. Stress due to on-off switching of pumps is mainly a result of high inrush currents at start-up. If you put a soft-starter or a vsd (speed drive) before a pump you limit this wear substantial. Obvious this is most relevant for larger expensive pumps. If you need a pump of less then 100W I wouldn't worry too much about start-up wear. Dry or submerged installation has both positives as well as negatives. My general advise; Small pump submerged with a magnet drive, bigger pumps dry installation, pump with shaft connecting motor & pump. Waste water pump submerged, as sucti
  12. Nicely done with the laundry baskets, although seems like a lot of work to make. As an alternative you can use 50 mm pvc to make a floating frame, covered with oyster mesh, fixed with cable ties. Make them big enough so a box grader fit in and you can grade on size within 1 tank.
  13. Hi Ande, Excellent find, although I have seen a number of these publications already.
  14. If you like flood and drain, a timer on the pump, and a double overflow (restricted bottom and unrestricted top overflow) will work more reliable than a bell syphon.
  15. Hi Pita, Hard to advice without seeing the actual configuration, but I don't think size of tubing is the problem as velocity in pipe is high enough. In general raceways have poor self-cleaning properties (one of the reasons to choose round tanks). You can actually improve self-cleaning abilities by creating circular flow in sections of the raceway; they call this design mixed-cell raceway, see https://cals.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop PP & Misc Papers Adobe 2006/4 Culture Tank Design/Mixed-cell Raceway/Labatut 2005 - Aqua Eng - Hydrodynamics.pdf
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