Blue drum – 200L plastic drum used in many areas of aquaponics. Can be cut in half vertically or horizontally to give two 100L grow beds. Care needs to be taken when obtaining these drums that toxic chemicals have not been stored in them. Depending on the previous use of the drum, they may be successfully cleaned and used in your system.

Crenellations – cover a greater surface area compared to a series of drilled holes and thus lets a greater water flow through, holes are more prone to clog. Think of the tops of medieval castles _|-|_|-|

Fish-safe silicone– (from a supplier) a medium modulus, one component, acetic cure silicone recommended specifically for the fabrication and repair of fresh or salt water aquariums. It forms a tough waterproof seal that won’t crack or shrink and is non-toxic to fish when fully cured after 7 to 14 days. Cure time depends on bead size and cure conditions.
Does not contain fungicides that will kill your fish.

Float switch – an electrical switch used to turn pumps on and off during pumping cycles. The usual configuration in aquaponics has the Switch switching ON when the float is in the UP position…. The switch switches the pump ON when the tank is full and then the pump being switched on will pump to empty the tank. When the float is DOWN, the pump switches OFF.

IBC– Industrial / Intermediate / International Bulk Carriers, 1000L, usually 1000mm x 1000mm x 1000mm (approx.) plastic cubes used to transport bulk liquids by road or rail. They are usually white / translucent and contained within a steel or aluminum cage on a pallet. Care needs to be taken when obtaining these ibc’s that toxic chemicals have not been stored in them. Specialist fittings are often required to couple to the tap in the bottom of the ibc.


Plastic types – some different types of plastic and other pipes and their usages

PVC Pipe

  • PVC stands for Polyvinyl Chloride.
  • Used for carrying cold water, irrigation, as a conduit and for DWV (drain-waste-vent) projects.
  • Rated by thickness and strength. Common ratings (thickest to thinnest) are Schedule 40 (most common), Class 315, Class 200 and Class 125 (generally used for irrigation).
  • Available in sizes from 1/2” to 2”. White in color 

    CPVC Pipe

  • CPVC stands for Chlorinated Polyvinyl Chloride.
  • Used for both hot and cold water supply or chemical distribution systems.
    • Good for temperatures at 200° F in pressure systems and non-pressure systems.
    • Requires special solvent cement that is different from cement used for other types of plastic solvents. Most solvents will indicate this on the can.

ABS Pipe

  • Means Acrylonitrile Butadiene Styrene.
  • Made from a thermoplastic resin. Lightweight and easier to use than metal pipe.
  • Commonly used for DWV (drain-waste-vent) applications or for underground electrical conduits.
  • Available as either solid wall or cellular core construction


Black Poly Pipe

  • Used for carrying low-pressure cold water. Common applications include golf course sprinklers, underground conduits or to carry corrosive liquids and gases.
  • Good chemical and crush resistance.
  • Lightweight enough to cut with an ordinary knife or a fine-toothed hacksaw blade.


PEX Pipe

  • PEX stands for cross linked polyethylene.
  • The chief advantage is its flexibility and strength. It can make turns around corners without couplings.
  • In a PEX plumbing system, a separate line is run from the main water supply to each fixture in a set up much like a circuit breaker box.
  • Used for carrying hot and cold water.
  • Excellent chemical resistance to acids and alkalis, but do not use for fuel oil, gasoline or kerosene systems.
  • Do not weld with solvents. Join with heat fusion, flare, crimp ring or compression fittings.


Galvanized Pipe

  •  Has zinc coating that prevents rust if not scratched.
  • Use primarily for carrying water or waste. Do not use for gas or steam.
  • Common water sizes are 3/8”, 1/2”, 3/4” and 1”. Common waste sizes are 1-1/2”, 2” and 3”.
  • Often sold in pre-threaded standard lengths, or can be custom threaded.
  • Use only with similar galvanized pipe fittings, not with black pipe fittings.
  • Measured using the I.D. (inside diameter)


Black Iron Pipe

  • Not treated for rust resistance.
  • Used for carrying steam or gas.
  • Used only with black iron pipe fittings, not galvanized fittings.
  • Measured using the I.D. (inside diameter).


Water Supply Tube

  • Used to connect a water supply line to a faucet fixture, toilet or appliances. Several types available.
  • Plastic type is flexible and inexpensive but not designed for exposed connections.
  • Ribbed chrome type bends easily without kinking.
  • Braided type features pre-attached connector nuts at both ends and can be flexed to fit.
  • Chrome-plated copper or brass tubes are more rigid than other types and are good for exposed applications.
  • The most common size is 3/8″, with lengths ranging from 6″ to 72″.


Vinyl Tubing

  • Economical and used in a variety of applications.
  • Usually joined with pressure fittings and clamps


Plastic Recognition By Burning

Plastics recognition – plastic type – Observations when lit with match and allowed to burn

PVC – Blackish smoke and acrid smell

Polyethylene – No smoke, drips like a candle and smells of wax

Polypropylene – No smoke, drips like a candle and smells of burnt oil

Polyamide – No smoke, pulls to form a thread, smells of burnt horn

Polycarbonate – Yellowish sooty smoke, sweetish smell

ABS – Blackish smoke, soot flakes, sweetish smell

Plumbing sizes / grades – PVC pipes come in pressure and DWV (Drain Waste Vent) grades. These are NOT the same thing. They are NOT the same size. Make sure before you buy the fittings and pipes that you get the same type of fittings. They will not match up easily and mixing them up can make for hassles and dodgy joins and unwanted expense.
Poly pipes come in pressure and rural grades. Again, these are NOT the same thing or size.
There are mainly differences in the thickness of the pipes and the strength of the joiners required to hold the pipes together.

Pumping head– Expression of pressure in height of water. The height of one body of water above another at the first place where it is open to the atmosphere. For example, if the water is piped from a lake in the hills down to a farm in the valley and the surface of the lake is 100m above the surface of the fish ponds, the water has a head of 100m at the level of the fish ponds. If however, the pipe is stopped halfway, the water allowed to form another lake and then piped the rest of the way, the head at the fish tanks will only be 50m see also friction loss for calculations for air and water loss in pipes.

Many pumps will state, for example, 10m maximum head. This means if you are pumping to 10m high, you will deliver 0L water per hour (not much use to anyone really). But the same pump, pumping to 4m high, will deliver about 200L (all figures examples only)

Sump – General term for a tank or chamber used as a reservoir, stilling chamber or water collection point.

Timer – often used to regulate flood and drain cycles. Varying on / off cycles available. Also, varying degrees of program ability.

Hygrometer – An instrument for measuring relative humidity in the atmosphere.