Spirulina and Crawfish Cultivation Pool

Design Rationale

The reason for this dual purpose tank is that both of these organisms have a synergistic effect on each other; the spirulina achieves optimal growth at a pH of 8.04 and will dominate over other cyanobacteria that produce toxins, and crayfish can survive in these highly basic conditions, and can feed off of the spirulina. This forms the basis of an exceptionally robust nutrient web that enriches the nutritional value of everything produced later in this aquaculture nutrient cycle, from most vitamins and minerals to complete proteins, all of which are essential for human life.

Function

Sterilized (no active cultures) nutrient bath of a highly basic pH is used to culture the spirulina on which the crayfish feed.After this, a vortex filter is used to remove the solid waste produced by the crayfish and flows into a monoculture tank of spirulina for human consumption. The crayfish waste is used in the compost tea nutrient cycle. Sterile nutrient bath composed of rock dust, greywater that has already been converted in a biofilter into bioavailable forms of nitrogen, as Arthrospira is not capable of nitrogen fixation. Sterilization can occur in an apparatus that irradiates the nutrient bath with UV radiation via UV light emitting diodes. This also makes a good dish sterilizer for a kitchen.

Inputs

• Graywater
• Rock dust
• Carbonate or bicarbonate source

Outputs

• http://en.wikipedia.org/wiki/Arthrospira
• Various species of crayfish
• Crayfish feces

Materials

• CEB Water Cistern
• UV LED arrays
• 1/4" Polycarbonate sheets
• Various ABS irrigation fixtures
• Silicon caulking
• Stainless Steel Hardware
• Liquid Rubber Sealant [1]