The role of calcium is not to be underestimated! I have
seen a rapid increase in growth rate in hard water as
compared to soft water. Calcium is not the only
essential element. Magnessium is also very NB. Shell
grit is very useful in this repect as it holds large
amounts of both Ca and Mg but not only as the carbonate
forms (which are largely insoluable except at low pH)
but also phosphates which are more soluable. My
boesemani rocketted once they were in my tanganyikan
tank and they started colouring up from a small size
(some are only 3cm long!, granted these are the runts of
the litter).
Often, to boost bone growth Calcium is added to the
water, inspite of this bone deformities persist due to
the lack of Magnesium. Also, many of the calcium
additives don't disolve effectively (as they are
carbonate based). Then to top it off, home breeders may
not light the tank with an adequate UV source as as such
the fish can't synthesize enough vitamin D, which can be
deficent in diet.
For maximum growth of many fish, hardened water with a
good flourescent light is best. Shell grit is a better
source of calcium as opposed to coral chips (which being
argonite are mainly CaCO3). I use both coral chips and
shell grit mainly to stablize the pH. Very little
Calcium and Magnessium really disolves unless there is
very active Nitrobactor activity which can produce
enough acid to dissolve the coral chips/shell grit.
Coincidently, if you are battling to grow plants, add
some shell grit around the root and stay away from those
plant fertilizers that have chellated Fe carriers for a
bit. Also don't add plant fertilizers with N and P in as
this is pointless. Rather add trace ellement and K
(which is the element most often in need).
Just a few thoughts...
Bye
Tyrone Genade
Southern African Killifish Society Coastal & Offshore Coordinator
AKA 08248
tyronegenade at yahoo.com
http://www.geocities.com/tyronegenade
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P450 Lab, Biochemistry Department
University of Stellenbosch, 7602, South Africa
Ph: +27-021-808-5876, fax: +27-021-808-5863
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In God I trust,
but in all others I must have irrefutable proof!