What are the major expenses?
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Tank and stand
Light
Substrate
CO2
Fertilizers
How to live on the cheap.
• Tanks and Stand -- buy used and pay no
more than $1-2 per gallon. Re-paint stand as
needed. Hammer in a few boards to make it
more sturdy/look better
• Lights -- use 48” electronic T8 fixtures that
you can get at the hard ware store for ~$20
How to live on the cheapsubstrate
• Substrate -- buy plain gravel or sand (also from hard
ware store esp. if you can get the no-salt sand for icy
roads)
• Supplement in moderation with things like
peat/soil (~1cup/ square foot) ironite (~1 T/square
foot),
• I like to make clay balls with added nutrients and
add them both before and after a tank is planted. I
recently set up a tank with nothing but clay balls.
And plain gravel
How to live on the cheap --CO2
• I have used yeast CO2 on tanks up to 180
gal. Also 75s, 65s etc.
• 2 gallons of yeast changed once every 3wks
to month depending on the temperature
works well. I don’t rotate the bottles either.
• The key to long lasting cultures is allowing
them to grow and be happy. Also a little
basic knowledge of yeast growth helps.
Yeast Growth/metabolism
• Yeast can either produce energy by fermentation
or oxidative phosphorylation (ox/phos)
• Yeast greatly prefer fermentation over ox/phos and
will not start ox/phos until all the sugars are
converted to ethanol.
• Ethanol is a good source of energy and in the
presence of oxygen yeast use it up as well.
• Fermentation also produces 2 CO2 molecules per
molecule of sugar-- as a by product. =)
Why is just sugar and water not
ideal?
• When you just add sugar and water to yeast, they
are essentially starving to death.
• However the enzymes for converting sugar to
ethanol are still in the cell and will work for a
limited amount of time.
• Since the cells do not have what they need to
make new enzymes as cells starve/run out of
enzymes the culture produces less and less CO2.
Also, we add too much sugar.
• Ethanol and sugar are increasingly toxic to yeast
at greater than 10% concentrations.
– Therefore 2cups (~500ml) of sugar in 2L of water
(~25% sugar) is unhealthy for the yeast.
– It is also a waste of sugar because 10% sugar will yield
roughly 10% Ethanol at which point the yeast stop
growing anyway.
– Special strains of yeast, like champaine and wine yeast,
have stronger cell walls that protect them from the
Ethanol -- so they grow longer.
Happy yeast give you long,
productive cultures.
• The solution is to give yeast less sugar and also
supply them with the nutrients they need to grow.
• This will give you a long lived culture that
produces a consistent amount of CO2, (they are
not challenged by toxic conditions at the
beginning and end)
• Also your yeast mass at the end will be alive and
well and able to quickly start growing again when
you add more sugar.
The Recipe!
• Improvise at will, but here is a good start:
– Use 1 cup sugar per 2L H20 (tank water is great or
dechlorinated tap -- chlorine, but not ammonia, kill
yeast. ) (they like ammonia)
– Add 1-2 tsp of a protein drink mix
– (optional) Add 1 tsp of ammonium sulfate, otherwise
use 1 T mollasses. (or both)
– 1 tsp baking soda is also nice to keep the pH from
crashing (they like it >pH3-4)
Leave yeast from previous mix in the bottom.
Benefits/conclusons
• Growing yeast this way saves you time (less
re-starting) and money on sugar and yeast.
• The only real extra cost is the protein mix,
but you can use really old/cheap stuff.
– The key thing is that it has protein and
vitamin/minerals, Anything that has “yeast
extract” in it is perfect.
– (Even non-fat powdered milk will do the trick,
but it will smell funny)