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Hadean: Aquaculture

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This topic contains 7 replies, has 3 voices, and was last updated by Avatar of elspru elspru 3 years ago.

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #1484
    Avatar of xns
    xns
    Participant

    Built a small 7000 liter hatchery into the back yard 2 months ago, put in the milkfish(Chanos chanos) 2 weeks back to start the nitrogen cycle and clean out the diatoms. It’s still a few weeks away from having a perfectly balanced ecosystem but I should be dropping the fry in on the 15th April 2011. Projected production is 4000 fingerlings of most common food fish(perciformes) a year. Each one being about 6 inches in length and 200g in weight before we send them to the grow-out farm.
    See the little milkfish in the top-right corner? They’ve actually put on weight since we put them in. They’re schooling fish and completely incapable of harming the fry since they’re filter feeders.
    New mangrove shoots in the sump. This particular genus, Rhizophora, is locally known as “Bakau” in malay. It’s an excellent construction timber, highly resistant to decomposition and makes good firewood.
    View from the left
    View from the right.
    #13242
    Avatar of elspru
    elspru
    Participant

    hey here the second fish example in this ted talk is of a sustainable permaculture fish farm ecosystem

    http://www.ted.com/talks/view/lang/eng//id/790

    In case you don’t already, I’d recommend having a deep sand bed, or a soil layer at least 10-15 cm thick, preferably with some worms in them, to allow for complete nitrogen and sulphur cycles.

    Also it seems like having more plants could be useful as a renewable food source for the fish.

    calm aware desire choice love express intuit move

    #13244
    Avatar of xns
    xns
    Participant

    DSBs are only a requirement if you don’t have any photosynthetic life, plants are several thousand times more efficient. And once you start putting little benthic organisms like worms, seastars, crabs or cukes, they stir the sand up too much for it to become anaerobic. Especially the cukes and crabs.

    King Shannon of the Constitutional Monarchy of Logos.

    #13252
    Avatar of elspru
    elspru
    Participant

    xns wrote:

    DSBs are only a requirement if you don’t have any photosynthetic life, plants are several thousand times more efficient.

    actually DSB’s handle things that plants don’t, including turning ammonia into nitrates, and hydrogen-sulfide into sulphates.

    And once you start putting little benthic organisms like worms, seastars, crabs or cukes, they stir the sand up too much for it to become anaerobic. Especially the cukes and crabs.

    Yes, benthic organisms are highly recomended, the DSB is a habitat for them, while at the same time they promote nutrient exchange between the different layers.

    calm aware desire choice love express intuit move

    #13258
    Avatar of J.L.-Frusha
    J.L.-Frusha
    Participant

    Look up Vermiponics.

    It’s aquaponics including a worm bed…

    Later,

    J.L.F.

    Never be afraid to try something new…

    Remember, amateurs built the ark, professionals built the Titanic.

    #13259
    Avatar of J.L.-Frusha
    J.L.-Frusha
    Participant

    Actually, I think it could be done in an aquaponics plant bed, just add the worms… Might need to add screen to exclude them from the drain, but otherwise, they should do well in the plant bed, if it’s deep enough and the water is well aerated…

    Later,

    J.L.F.

    Never be afraid to try something new…

    Remember, amateurs built the ark, professionals built the Titanic.

    #13261
    Avatar of xns
    xns
    Participant

    I really should clarify: A Deep Sand Bed used in marine aquariums is more than just a thick layer of sand. It must first have anaerobic conditions to allow for anaerobic bacteria to convert nitrates(NO3) which is mildly toxic to nitrogen gas(N2) which is inert.

    One risk with this system is the production of very toxic hydrogen sulphide(H2S) which occurs in anaerobic conditions.

    The other problem is that few sandbeds are actually deep enough to accommodate benthic organisms while still remaining anaerobic.

    What elspru refers to in his earlier post as a DSB is actually “Live Sand Bed”. I.e. one with a working benthic ecosystem. Which we have in the sump with the mangroves.

    And none of this should be confused with the nitrate cycle described earlier, where ammonia(NH4) is converted to nitrite(NO2) and nitrate(N03) compounds on all surfaces of the aquarium. Which is why the hatchery incorporates both sellable benthic organisms like crabs, sea cucumbers, prawns and bristleworms(tackle shops buy these) as well as plants and macroalgae that remove ammonia and nitrates.

    And in case it wasn’t clear before, the system is marine. Not freshwater, I haven’t seen any vermiponics systems that’ve managed to incorporate bristleworms yet. Though J.L is right in the sense that the benthic critters perform much the same function as Eisenia foetida(red wrigglers) in freshwater vermiponics setups.

    Hope that makes the chemistry clear.

    King Shannon of the Constitutional Monarchy of Logos.

    #13263
    Avatar of elspru
    elspru
    Participant

    xns wrote:

    And in case it wasn’t clear before, the system is marine. Not freshwater, I haven’t seen any vermiponics systems that’ve managed to incorporate bristleworms yet. Though J.L is right in the sense that the benthic critters perform much the same function as Eisenia foetida(red wrigglers) in freshwater vermiponics setups.

    I have a DSB in my freshwater aquarium, it has freshwater worms.

    Hope that makes the chemistry clear.

    dsb diagram

    calm aware desire choice love express intuit move

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