Version 2012-III |
Summary |
Minor and trace elements in reef tank with regard to
water exchange
(type of used salt) and use of additives |
| |
Přirozeně koncentrovaná sůl |
Obohacená sůl |
| No additives |
Low concentrations
Critical time: 12–22 months |
Imbalance
Critical time: 12–18 months
|
| Use of additives |
Correct concentrations
Long-term stable environment |
High concentrations
Critical time: 6–18 months |
| The critical time is the time
span
after which one would expect encountering serious problems in
the tank. |
|
Use of enriched salt |
|
When using enriched salt for seawater make-up the main drawback is that
its composition (trace elements concentration) is fixed and unchangeable. |
Due to this fact it is not possible to react to specific divergent
parameters
of various tanks at a given time:
- coral growth extent
- coral types (soft / hard)
- tank life cycle
phase (small growing corals / large corals)
- specific intentions of
tank keeper (i.e. temporary cease of nutrients supply)
Furthermore the user of enriched salt deprives himself of the possibility
to use the water exchange in order to remove parts of excess nutrients or
to decrease the concentration of impurities – each water exchange with the
use of enriched salt increases the mineral nutrient composition in the tank
and widens the gap of the concentration imbalance of minor and trace elements. |
|
A high element concentration in marine salt is not an advantage; on the
contrary it is an irreversible disadvantage. It deprives the tank operator
of the power to influence the chemistry of the tank in a flexile and complete
manner. |
| |
Enriched Salt – No Additives |
| Situation with regard to the concentration of minor
and trace elements |
| Critical Time |
15 months |
(12 - 18) |
| Problems |
Concentration imbalance |
Steady state - critical deficiency of certain elements. |
| Steady state - critical excess of certain elements -
toxicity. |
| Occurrences |
A combination of often contradictory occurrences, as
for instance death of certain coral species, while at the same time
others grow and prosper. Growth of undesirable algae and cyanobacteria. |
| Solution |
Water exchange |
No |
Water exchange while using the same type of salt does not solve
the problem; it rather deepens the imbalance. |
| Use of sorbents |
No |
Decreases on one hand the high concentration of elements, but on
the other hand decreases also the concentration of other elements, which
were originally at correct or even low levels. |
One-time application
of additives |
No |
Increases on one hand the low concentration of elements, but at
the same time increases also the concentration of other elements, which
were originally either at correct or even high levels. |
| Switch-over to the use of naturally concentrated salt
and regular application of additives. |
|
Enriched Salt – Use of Additives |
| Situation with regard to the concentration of minor
and trace elements |
| Critical Time |
12 months |
(6 - 18) |
| Problems |
High concentrations |
Steady state - critical excess of certain elements -
toxicity. |
| An excessive application of additives leads to the continuous
increase of the concentration of certain elements - the critical time
is reached faster. |
| Occurrences |
Growth of undesirable algae and cyanobacteria. Sudden
tank collapse
- massive death of corals and other living organisms. |
| Solution |
Water exchange |
No |
Water exchange while using the same type of salt does not solve
the problem; it rather worsens the situation. |
Use
of sorbents |
No |
It does decrease of the high concentration of elements, but each
element to a different extent - the result is a concentration imbalance
(see "Enriched Salt – Use of Additives" variant). The massive
use of sorbents could lead to the complete elimination of minor and
trace elements from the tank; it is undesirable shock interference
to the living environment of the organisms - no possibility to create
a stable environment. |
Discontinuation
of additives
application |
No |
This means in principle a switch-over to the "Enriched Salt
– No Additives" variant with all related problems. |
| Switch-over to the use of naturally concentrated salt
and regular application of additives. |
|
Use of naturally concentrated salt |
Naturally Concentrated Salt – No Additives |
| Situation with regard to the concentration of minor
and trace elements |
| Critical Time |
17 months |
(12 - 22) |
| Problems |
Low concentrations |
Steady state - critical deficiency of certain elements. |
| Occurrences |
The coral growth rate drops at first and may eventually
sink all the way to zero; the corals then lose their natural bright
coloration. Due to the fact that corals with a lower growth rate demand
a lower supply of nutrients from seawater, their depletion rate also
drops. Thus, this also leads to a prolongation of the critical time
and the tank may stagnate without significant problems for a relatively
long time, up to two years. In any case one should also bear in mind
a higher coral susceptibility to diseases, which might manifest itself
anytime. |
| Solution |
Water exchange |
No |
Water exchange while using the same type of salt would have results
only if a 100% exchange of the tank volume would occur. |
One-time application
of additives |
No |
It will only briefly even up the elements concentration to the right
level. Afterwards the concentration of all elements will again sink
continuously. |
| Switch-over to the variant with regular application
of additives. |
|
Conclusions |
Naturally Concentrated Salt – Use of Additives |
Based on the facts stated in this and in the previous article it is
evident, that the regular application of additives in combination with
water exchange, produced using naturally concentrated salt, brings to
the reef tank maintenance the following key advantages:
- the possibility
to create a long-term stable environment
- minimal risk of reaching toxic
concentrations of minor and trace elements
- minimal influence of minor
and trace elements from the side of the operator
- the possibility to
use water change as a tool for the fast decrease
of the high concentration
of mineral and organic nutrients
and unwanted materials, without the
risk of the consequent ion imbalance
|
| |
Marine Salt and DOM (Dissolved Organic Matter) |
Dissolved organic matter (DOM) is for the tank prosperity in comparison
to minor and trace elements equally, if not even more important. It is
therefore advisable to operate with DOM in the same manner as with minor
and trace elements. This is why the optimal condition would be to use
marine salt containing natural concentrations of all important compounds
that constitute natural seawater, including DOM.
|
| |
Testable and Non-testable elements and compounds |
The exact measurement of the concentration of the vast majority
of minor and trace elements and organic compounds in the tank is in common
aquaristics practice infeasible, with the exception of the following
minor elements:
- I - Iodine
- Sr - Strontium
- B - Boron
- K - Potassium
For these
elements it is purposeful to measure their concentrations in the tank
and adjust them accordingly with independent additives.
When it comes
to trace elements and DOM it is in principle indifferent if mixed or
individual additives are being used. A key element is the monitoring
of the tank conditions and then adjusting the dosage of the related
additives accordingly. When used responsibly the only risk is the increased
mineral and organic nutrient content, which is responsible for the
growth of undesirable algae and cyanobacteria. In such a case it is
necessary to decrease the dosage of the related additives (alternatively
even discontinue their application for a certain period of time) and
wait till situation improves. |
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