Backyard Aquaponics
A place to discuss aquaponics

Yabbie will be aggressive in any conditions, as long as they can see the opposition they will fight, Marron are said to like pH of around 8, mine living in pH 6, and I have tested dam and river water where Marron live and best is just over 7 got me buggered who wrote about 8, unless you were a Marron you wouldn't know what you preferred

[quote="Nocky"]got me buggered who wrote about 8, unless you were a Marron you wouldn't know what you preferred[quote]

From PIRSA fact sheet ...

pH is the measure of the concentration of Hydrogen ions (H+) in the

water. Water with a pH of
above 7 is considered to be alkaline (low concentration of H+) whereas

a pH level of below 7 is
acidic (high concentration of H+). pH levels in freshwater ponds

depend on factors such as
nature of the catchment area (eg limestone areas would have a high pH)

and the amount of
respiration and photosynthesis occurring in the pond (ie the amount of

carbon dioxide present –
carbon dioxide dissolves in water to form carbonic acid).
Water with a pH between 7.5 and 8.5 are recommended however yabbies

can tolerate a pH of
7.0 and 9.0. A pH of below 7.0 will increase the toxicity of dissolved

metals within the water
column and soften the exoskeleton of the yabbie. A pH of above 9.0

will greatly increase the
toxicity of ammonia within the ponds.

... same also on marron fact sheet & very reason I won't be including them in aquaponics
Just don't want the hassles if can be avoided ...

But great for people who top up from a bore and have their pH sit at 7.4-8 the whole time

Gotta' admit I won't be getting to make much of a meal
from what I'm doing ...
It's more like growing the biggest pumpkin or hottest chile.
The largest I've heard of local commercial marron is 750 grams,
yet they have potential to grow to 2KGs - farmers just can't wait
the lenghth of time, to see that happen & why spiny crays aren't suitable for farming.
Still looking forward to getting aquaponics going also

Sorry about the late reply guys, but YEP - pain in the ass. I'm down to about 100 out of 180. Tank is 600mm deep, but is variable throughout to due to several brick towers and large lumps of limestone. Basic problem is deaths, usually from fighting, when they die and you can't find 'em - plays havoc with the water quality.

I like yabbies, and the survivors certainly seem to be doing well - lots of moulting going on over the last few months - and all very blue. But just can't help thiking there are better things I could be doing with that 2000L of tank space. !