1.2 Additives
Description
This article is from the ReefKeepers FAQ, by several authors (see the Credits section).
1.2 Additives
Calcium (Ca) - required addition. A range of 400-450 ppm Ca++
(10-11 mM) is recommended. The preferred method is the usage of
Kalkwasser (Limewater) for all evaporation make-up water. The use
of Calcium Chloride (CaCl2) is known to cause problems with alkalinity
(provable by balancing the relavent chemical reactions occuring in the
tank when CaCl2 is added). Still, CaCl2 is occassionally useful to
repair serious Ca++ deficits.
Chelated calcium:
The efficacy of chelated calcium products available for reef aquaria is
questionable. To the best of our knowledge, there exists no scientific
evidence indicating that chelated calcium is especially available to
corals and other CaCO3 depositing invertebrates. Nothing is known about
the uptake of chelated calcium products by coral. And most importantly,
there exists no evidence showing that chelated calcium products support
stony coral growth rates in excess of, or even *comparable to* growth
rates documented in aquaria where calcium is supplied as aqueous Ca(OH)2
[kalkwasser.]
Chelated calcium products also interfere with the ability to measure
actual calcium levels in the aquarium. In particular, chelated calcium
cannot be measured by any kit which uses EDTA titration, including the
highly recommended HACH kit. Some people find the SeaChem kit, which
does measure chelated calcium, to be impossible to read with any
accuracy.
Until such a time as vendors supplying chelated calcium products make
available well conceived, carefully documented uptake and growth studies
with their products, or the same experiments are performed and published
by third parties, we regard the use of chelated calcium products in the
reef aquarium to be experimental at best, especially when kalkwasser
and other non-chelated calcium sources are KNOWN to us to support the
growth and even reproduction of stony corals in the home aquarium.
Iodine (I) - enhances soft coral growth. It is removed by
skimming.
Strontium (Sr) - used rapidly by most hard corals (weekly
additions usually performed).
Buffers - increase alkalinity and control pH. Desired range is
2.5-3.5 meq/L (7-10 dKH) alkalinity. Alkalinity can be raised by the
addition of one of many commercial buffer compounds. The addition of
kalkwasser (saturated Ca(OH)2 solution - also known as
"limewater"), which is often done to maintain calcium levels, will
also raise the alkalinity level. SeaChem's Marine Buffer, Reef
Builder and Kent's Superbuffer dKH are popular. The Coralife and
Thiel buffer products have had less favorable reviews.
Iron (Fe) - Used by algaes. Add this if you want good macroalgae
growth. Be sure that macroalgae growth is favored or else plague
levels of hair algae may result.
Copper (Cu) - Used as a medication in fish-only tanks. Copper is
highly toxic to invertebrates, even in very small concentrations.
DO NOT USE THIS, IN ANY FORM, EVER, IN A REEF TANK OR ANY TANK
WHICH CONTAINS INVERTEBRATES. PERIOD!
Other additives, especially the commercial "secret formula"
mixtures, are more controversial. Some people report good results
from some of them other people report disaster or no effect.
Experiment cautiously with them if desired.
Continue to:
My Books
