Community land trusts (CLTs) - unstructured notes TODO



Tax increment financing


Notes on aquaponics

How aquaponics works (in a tiny nutshell)

  • fish effluence → clarifier/settler for anaerobic mineralization → biofilter for nitrification (aerobic NH3 + H2O → NO2 → NO3) → grow bed → sump → rearing tank
  • 0.5–1 lb fish ←→1 gal water ←→0.5–1 sqft grow bed
  • recirculating/closed-loop/media culture aquaponics vs. nutrient film technique vs. deep-water raft aquaponics
  • system inputs: fish feed, iron, magnesium

Notes from Aquaponic Gardening by Sylvia Bernstein

  • The Aquaponic Gardening Community
  • “Much of the greenhouse tomato, basil and lettuce production in North America today is done using hydroponic growing techniques…”


  • needs to cover blue/red spectrum
  • fluorescent lighting with T5 bulbs
    • broad plant lighting spectrum
    • low power consumers, low heat
    • only reach through 18in (45cm) of plant canopy
    • need to replace every 6mo
  • high-intensity discharge (HID) lighting
    • metal halide (MH) for vegetative growth or high-pressure sodium (HPS) for mature/productive stage of fruiting plant
  • LED lighting
    • no heat, very low power consumption -> never replace bulbs
  • asdf

Grow beds and fish tanks

  • media bed better than NFT or deep-water culture (raft/DWC)
  • basic flood and drain: simplest design, for 1:1 grow bed to fish tank volume
  • add sump tank (CHIFT PIST/CHOP)
  • CHOP2: along with CHOP, allows 2-3:1 grow bed to fish tank ratio
  • Barrel-ponics
  • hybrid system
  • grow bed
    • industry standard >= 12in (30cm) deep for plant roots and complete filtration
    • media guard
  • fish tank
    • = 250gal (1000L) better for stability

    • need >= 50gal (200L) to raise fish to plate size, 12in (30cm)


  • pump
    • flow rate
    • head pressure, lift
  • pipes
    • usually polyvinyl chloride (PVC) or chlorinated polyvinyl chloride (CPVC)
    • half-inch (12mm) inner diameter PVC
    • alt to PVC: high-density polyethylene (HDPE)
  • pipe attachment
    • marine-grade silicone
    • Uniseals
    • bulkhead fitting
  • pump timer
    • mechanical or electronic timer
    • no-timer systems include autosiphons, flush valve systems
    • flood once per hour (15min on, 45min off)
    • flow entire folume of fish tank throw grow bed(s) every hour; e.g. 100gal tank with 15min on/hr needs a 400gph (gallon-per-hour) pump
  • Construction of automatic bell siphons

Grow media

  • 3 filtering functions
    • mechanical solid removal
    • mineralizzation (solids breakdown, return to water)
    • biofiltration
  • grow media purposes
    • structural
    • biofilter for solid waste
    • home for worms
    • air/water exchange
    • temperature moderation
  • media
    • cannot change water pH
    • cannot decompose
    • 12-18mm in diameter
    • should be porous
    • lightweight expanded clay aggregate (LECA/Hydroton), lava rock, expanded shale, gravel
  • gravel weighs 105lb/ft3 (1682kg/m3)


  • water weighs 8lb/gal (1kg/L)
  • municipal water supply usually contains chlorine or chloramines, must be off-gassed
  • heating
    • aquarium heater
    • swimming pool heater for large tank; e.g. with titanium heating element
    • hydronic, radiant, or “in-floor” heating
  • dissolved oxygen
    • break surface tension of fish tank
    • aeration device for supplemental oxygenation
    • must be >3ppm, preferably >6ppm
  • pH
    • API Freshwater Master Test Kit (weekly) or digital pH meter
    • pH buffering agent
    • to raise pH: calcium hydroxide (hydrated lime), calcium carbonate (agricultural lime) with potassium carbonate, bicarbonate, potassium hydroxide (pearlash/potash)
    • to lower pH: hydroponic acids (nitric, phosphoric), vinegar; do not use citric acid
    • fish 6.5 - 8.0, plants 5.0 - 7.0, red words and bacteria 6.0 - 8.0
    • must be 6.4 - 7.6, optimally 6.8-7.0
    • tends to rise during cycling


  • 1lb (500g) fish for every 5-10gal (20-40L) for home media-based system
  • tilapia, goldfish, catfish, koi
  • shrimp, barramundi, pacu, perch, trout, oscars, freshwater lobster
  • keep temperature within 2C in 24hr period
  • feed 5min worth of food every hour
  • adult fish eat 1% of body weight per day, juvenile 7%
  • homegrown feed
    • duckweed
    • earthworms, sludge worms, bloodworms, composting red worms (red wrigglers)
    • black soldier fly larvae (BSF); check out BioPod


  • cannot grow plants that prefer too acidic or basic
    • acidic soil: blueberries azaleas
    • basic soil: chrysanthemums, calendula, zinnias
  • oxygen, hydrogen, carbon from air (O2, CO2) and water (H2O)
  • macronutrients: calcium, nitrogen, magnesium, phosphorus, potassium, sulfur
  • micronutrients: boron, copper, iron, manganese, molybdenum, zinc, aluminum
  • plant temperature depends on water temperature

Bacteria and worms

  • nitrifying bacteria: nitrosomonas and nitrospira
    • aerobic autotrophs
    • efficient at converting ammonica and nitrites
  • nitrosomonas convert ammonia to nitrites
  • nitrospira convert nitrites to nitrates
  • nitrosomonas NH4+ + 1.5O2 -> NO2- + 2H+ + H2O + 84kcal/mol of ammonia
  • nitrospira NO2- + 0.5O2 -> NO3- + 17.8 kcal/mol of nitrite
  • overall NH4+ + 2O2 -> NO3- + 2H+ + H2O + energy
  • optimal temperature 77-86F (25-30C)
  • maintain pH 6.0 - 8.5; nitrosomonas optimal 7.8 - 8.0, nitrospira 7.3-7.5
  • composting red worms for solid waste
    • worm castings or vermicompost


  • Cycling
  • System maintenance
  • Appendices

Good intros

More readings

  • Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together by Sylvia Bernstein
  • Aquaponics by Williams Walsworth
  • The Spotless Garden

Forums and threads

Other links


Random notes

  • tilapia, perch, trout, hybrid striped bass, catfish, koi
  • shrimp, crayfish, shellfish
  • ducks, chickens, quail
  • bees
  • freshwater species



Vertical farms

The Ignorant Man's Book Collection

The Ignorant Man’s Book Collection is a general reading list of reliable entry-level reference texts for a relatively wide range of topics, hopefully with enough reading material to stay ignorant for a lifetime. This list originally started as a Wikipedia essay. This is a very rough work-in-progress.

Essential texts are listed in bold. Within the same subjects, texts are roughly ordered by increasing depth, with introductory texts at the top. Complementary texts and related resources are listed in the nested bullet points.


Mathematical Analysis

Abstract Algebra

  • Algebra 18.701, 18.702
  • Lie Groups 18.755
  • Topology 18.901
  • opology by J. Munkries


  • Algebraic Geometry 18.725
  • Differential Geometry 18.950
  • Riemannian Geometry


  • Basic Physics 8.01, 8.02, 8.03
  • Thermodynamics 5.60
  • Landau and Lifshitz’s Course of Theoretical Physics



  • Electricity and Magnetism by Edward M. Purcell
  • Introduction to Electrodynamics by David J. Griffiths
  • Electromagnetic Fields 6.013, Electrodynamics 6.014

  • Statistical Mechanics
  • Tensor Analysis

Astrophysics & Cosmology

  • An Introduction to Modern Astrophysics by Bradley Carroll and Dale Ostlie
    • The Physical Universe: An Introduction to Astronomy by Frank Shu [supplement]
    • Introduction to Cosmology by Barbara Ryden


Organic Chemistry

Physical Chemistry


Molecular Cell Biology

  • Molecular Biology of the Cell by Bruce Alberts
    • Molecular Cell Biology by Harvey Lodish, Arnold Berk, Chris A. Kaiser, Monty Kreiger, Matthew P. Scott, Anthony Bretscher, Hidde Ploegh, and Paul Matsudaira



  • Principles of Neural Science by Eric Kandel, James Schwartz, and Thomas Jessell


Computer Science

  • Structure and Interpretation of Computer Programs by Harold Abelson and Gerald Jay Sussman with Julie Sussman

Algorithms and data structures


Artificial intelligence

Computer architecture



Computer security


Distributed systems

Software engineering

Electrical Engineering




Integrated circuits

Signals and Systems

Image Processing

  • Digital Image Processing by Rafael C. Gonzalez and Richard E. Woods

Controls Engineering

Mechanical Engineering


  • Introduction to Flight by John D. Anderson Jr.
  • Fundamentals of Aerodynamics by John D. Anderson Jr.
  • Fundamentals of Astrodynamics by Roger R. Bate, Donald D. Mueller, and Jerry E. White
  • Space Mission Analysis and Design by Wiley J. Larson and James R. Wertz


Industrial Engineering

Social sciences

  • [[Social science#Branches of social science]]






  • A People’s History of the United States: 1492 to Present by Howard Zinn
  • A People’s History of the World: From the Stone Age to the New Millennium by Chris Harman


  • Manufacturing Consent: The Political Economy of the Mass Media by Edward S. Herman and Noam Chomsky
  • Understanding Power: The Indispensible Chomsky by Noam Chomsky, John Schoeffel, and R. Mitchell


Updated 2018-02-26

Podcast recommendations

A list of podcasts and radio shows that I think are worth listening to. Hopefully a good starting point for anyone looking for recommendations.

First stringers are listed in bold.

Frivolity (comedy, sports, trivia)

Interviews & lectures


Policy & media criticism

Politics & news

Science & humanities


Technology & design


Updated 2019-02-03

Working list of productive hobbies

This is a working list of hobbies, gigs, volunteer opportunities, and other activities that don’t take place in a work office, with ratings (on a scale of 0-3) of how productive they are at

  • keeping you in shape
  • wetting you this money
  • exercising your creativity
  • enriching your social life

The list was mostly compiled from available lists of hobbies—with some emphasis on activities that people I know have done or that I’ve found interesting at some point—and the productivity criteria were inspired by the piece of Internet advice “Find three hobbies you love: one to keep you in shape, one to make you money, and one to be creative”. I’m open to suggestions for additions to this list and edits to any of the ratings.

Updated 2018-09-17