Transcript Safe Plants and Decorations for Your Aquarium and Aquatic

Safe Plants and Decorations
for Your Aquarium and Aquatic
Friends
Researched and Formatted by: Juanita
Hoffman
Introduction
Before adding any
decoration to your aquarium
you must take several things
into consideration. First and
foremost is the question, “Is
the plant or item that I want
to add to this tank safe for
my fish?” Next thing to
consider is how adding the
decorations will affect your
aquatic friends.
Live Plants ~vs.~ Artificial
Making the decision to use live plants has
benefits as well as some negative things
to take into consideration.
In the next section you will find pros and
cons for both live and artificial plants.
As you will see there are plenty pros and
cons for each option. A well planned and
maintained aquarium can be beautiful with
either real or artificial plants.
Deciding: Live
Pros:
Absorbs CO2 (in daylight)
Gives off O2 (in daylight)
Absorbs toxins
Harbors beneficial bacteria
Serves as food source
Inhibits algae growth
Cons:
Can cause O2 deficiency at night
Creates waste when decayed
Can cause parasites
Not easy to clean
Requires good lighting
Deciding: Artificial
Pros:
Does not affect O2 levels
Does not create waste
Does not carry parasites
Easily removed and cleaned
Does not need special lighting
Cons:
Does not absorb CO2
Does not give off O2
Does not absorb toxins
Does not carry bacteria
Cannot be used as food source
Does not inhibit algae growth
Substrates
After deciding if you want to have live or
artificial plants you will need to decide on
the type of substrate that you want to use.
There are many forms of substrate
available, including gravel, sand and more.
While the choice is almost entirely up to
the consumer; fish safety and plant needs
(if live plants will be used) must be taken
into consideration.
Choosing your substrate
Aquarium substrates or gravel fulfills a few
functions for us as aquarists.
Gravel/sand provides living space for
beneficial microbes, perhaps alkaline
reserve and other chemicals for a
system. There may be behavioral
benefits for your livestock, anchoring for
plants... and, it looks good too. The
majority of aquarists use some form of
substrate in their tanks, though strictly
speaking they could leave the bottom
bare in most cases. Here is our
discussion of the Uses, Properties,
Varieties, and Application/Maintenance
of substrates for freshwater aquariums.
Choosing your substrate
Uses: Biological, Buffering, Biomineral, Psychological, Looks
Bacteria Homes:
First and foremost, gravels, sands and other solid décor in
aquariums function to support populations of beneficial
bacteria. There is a definitive relationship between the
microbes and macrobes (livestock) in your aquarium. The
most celebrated of these 'bio-geo-chemical cycles' is the
element Nitrogen. <refer folks to that chapter on cycling>
Well, where do all these bacteria 'live'? Mainly in and around the
substrate, though they are found on the tank walls, decor,
even on the inhabitants... You do need them… to provide
means to limit or remove the poisoning waste products and
by-products of your livestock.
Many/most aquarists opt for the 'gravel route' in their tanks or
filters as the least expensive, most secure method of getting
rid of metabolites and providing a safety-margin for the
eventuality of over-feeding, unnoticed death, or rapid
increase in stocking load of their system. By having lots of
space for beneficial microbe growth/metabolism
bottlenecking of vital chemical and physical reactions is
eliminated; balance (in your favor) is preserved.
Buffers: pH and Alkalinity of Water
Metabolism and purposeful feeding results in a decrease in the system's capacity to
resist a drop in pH, the water "becoming acid". The fancy description for this property
is alkaline reserve; it is the system's sum-total ability to keep its pH at a certain point.
All sources of freshwater have a varying alkalinity/alkaline reserve. That is, there are
chemical species dissolved, and precipitated (like sand, gravel, rock) that make up
the buffering capacity (alkaline and acidic) of your water. What you want is to keep
the pH stable and somewhere within the tolerance of your particular livestock. Some
animals and plants do best in more acidic water (below 7.0 in pH) like Discus and
South American Tetras, other types of livestock appreciate harder, more alkaline
water (with a pH higher than 7.0) like the life from the Great Lakes of East Africa. The
particular range of these values by species can be found in books like this one and
online sources like fishbase.org.
There are several ways to provide for sufficient alkaline reserve. Good particulate
filtration, chemical filtrants that remove organics, frequent partial water changes
which add more reserve and reduce metabolites, adding alkaline solids/solutions,...
all can and do their part in stabilizing, optimizing water quality, including preserving
alkaline (and other) reserves.
By utilizing an appropriate substrate you vastly add to the homeostasis and steady-state
capacity of your system. This happens substantially on two fronts: Biologically, you
have so much 'life' in the system that other outside force-effects are ameliorated; and
chemically, the gravel/sand/rock substrate dissolves, releasing chemical species that
counter-act falling pH et alia res.. Is this a good deal? Yes.
Psychological Benefits:
Remember the joke, "Do fish feel"? The answer, "Sure, they feel slimy". How
much stock do you place in the emotional awareness of 'simple creatures'?
There is plenty of scientific and anecdotal evidence that aquatic organisms
(including invertebrates) are sentient of physical elements of their captive
worlds. For my Senior Report in Ecology at San Diego State U., RMF did a
series of experiments on "Substrate Size Preference" by the crayfish
Procambarus clarkii, the incredible/edible crawdad from Louisiana.
Basically, I set up three ten-gallon tanks, each with three sizes of gravel,
alternating first, second, or third in placement. I placed a Procambarus,
allowed it to adjust for a while and periodically looked in, recording what
grade it seemed to stay over. Varying light, water depth, the size and sex of
the individuals tested showed the same result. This species of crayfish
displayed a statistical preference for finer gravel.
The point is hopefully made; your livestock can tell if there is gravel in their
tanks or not. Many of the species of catfishes, spiny eels, cichlids and more
that live "in" or above the bottom in the wild fare poorly without substrate in
aquaria. Would you like to continually live over a shiny, reflective "floor"?
Looks: The Aesthetics of Substrates
Several types of freshwater substrates are great appearing.
There is a wide range of size, shininess, and color to
choose from. Basic choices are natural or not, the latter
often being artificially colored then epoxy coated, and
therefore chemically inert. Natural gravels encompass
flints, silicates, dolomites/coral sand/shell materials, and
carbonaceous rock of various types, even crushed (and
hopefully tumbled) glass. Other than consideration as to
appearances, natural gravels can be useful adjuncts to
maintaining good water quality, slowly dissolving over
time.
Properties: Cost, Size, Shape, Grading, Surface Area, Quantity, Flow Rate,
& Composition
Cost of Acquisition:
"What, another expense?" "Okay, how much?" "Are you joking, for
rocks/gravel/sand?" You've come a long way from the sand-box,
distance, time and money-wise. Substrates can cost a pretty penny.
Be a conscientious consumer here and check around. There is a
wide array of what's available at different price points. Often, large
quantities (even hundred pound bags) will be your best buy… and
there are other than fish store sources for gravels… Often "sand and
concrete" supply sources carry substrates of use for aquariums.
Buy the best of what you want in the function and looks departments,
and be satisfied. This is a one-time purchase (for a couple of years)
and can be used beyond its aquarium life for other interesting
projects. Read through this section thoroughly re issues as to color,
size, shape, and composition of the material you’ll be using… for the
types of livestock you intend. One size/type does not "fit all".
Size of Substrate:
Size of the individual particles is important for two main reasons;
maximizing filter bed action and for natural gravels, solubility sites.
You don't want something too large or small; if too little there will be
compaction and too little circulation between the pieces, way big
and all the stuff you want to trap just goes through.
For the function of solubility's sake, the smaller the size, the better.
Imagine dissolving an Alka-Seltzer (tm) in one piece ("Plop") or
crushing it up first; which one would fizz faster? More surface area
allows faster dissolution.
For these practical reasons a grade of @ 1.5mm (approximately 1/16")
on the smallest size, to @ 5mm (3/16") diameter for the largest is
what you want. For most systems, practical uses substrates of about
1/8 " diameter are "just right"… ones that are larger call for more
volume to produce the same effects, smaller diameters, less
volume.
Shape:
The more broadly spherical the pieces of the substrate, the
more consistent the flow, and therefore less channeling
and packing-down. The complete reverse is found in
more flat offerings (like silica sand) that lay-down
amongst each other, effectively clogging-off water
circulation. Our favorite mental demonstration of this
principle is the comparison of a bed of poker chips
versus one of marbles. Get it? Go with the marbleshapes. Sharp edged substrates can cause other
troubles with freshwater livestock, cutting into the skin of
burrowing fishes, even snipping off the barbels of
scavenging catfishes.
Consistent Grade:
The mesh or 'number' of the granules is an
average number of pieces to make up a linear
inch; so the larger the number/mesh the greater
the size. As per the comments in size above you
want a particular size in the tank/filter, and for
the size to be uniform. Either buy the product
pre-screened or make and screen it yourself. At
most, the pieces should be no more than
twice/half the sizes of the largest/smallest in the
part of the system; for the channeling/packing
reasons.
Surface Area
Within realistic limits ought to be maximized
to increase solubility and space for
bacteria culture. What you want to
remember is that you want something
that's more porous than smooth. One
indication of a trade-off of solubility and
surface area is that the material is duller
vs. shinier; choose the less reflective.
Quantity:
How much is enough? Is there such a thing as too much? Depending
on the size, shape of the substrate, consideration of the volume of
circulation, bio-load of the system, esthetics... some writers suggest
from a pittance to a few inches. Most folks go with somewhere
between one and two inches above whatever filter plate or a bare
bottom. This works out to something like ten pounds of substrate per
square foot of bottom. Some writers encourage sloping the gravel
bed from front to back/ lower to higher… without employing
submerged wood, rocks, other décor for this terracing, you’ll find "it
all comes out level" in a while.
If you’re using undergravel filtration it is imminently important to cover
all the surface of the plates about equally to ensure some circulation
through all the filter bed. Periodic moving of decor, stirring or
vacuuming through all areas cuts down on the mal-effects of
anaerobiosis. We’ll mention much more about this under
maintenance.
Flow-Rate if Using Sub-Gravel
Filtration:
As a rule of thumb about two gallons a minute per square
foot of filter/tank surface area (2 gsfm) is about right in
terms of flow through the filter bed. There is no practical
upside limit, i.e. three gallons per square foot per minute
would be even better. For smaller systems you can get
this flow rate with large airlifts outfitted with (1 mm
bubble) uniform (air)stones, or powerheads. For big to
humongous tanks you'll want to employ a fluid-moving
pump system, possibly in conjunction with an outside
power filter rig. The preference here is to run the
circulation "reverse-flow", up through the filter plates
after the water has passed through the particulate and
chemical filtrants of the outside filter. Reverse flow setups provide much better for removal of sediment that
otherwise collects under filter plates.
Buffering: For Those Who
Need/Want It:
Your source water may be slightly to greatly alkaline to acidic. The
substrate could provide a needed or excess of carbonate ions to
neutralize the organic acids of the livestock. You will want to test
your water and perhaps pre-prepare it outside of the system in some
cases… storing it for future use in a convenient container. If you’re
fortunate to have tapwater that is "just about right" straight out, it
might be reasonable to use a substrate that will aid your efforts in
sustaining pH… one that is suitably alkaline and soluble.
Of the most likely substrates/gravels you're likely to find, there is a
direct and positive correlation with suitability, cost and carbonate
solubility. Once again, you need to investigate 1) Your water source
pH and alkalinity, 2) The needs, desired range of these qualities for
your intended livestock, and 3) Formulate a plan for providing a
stable means of supplying water quality within these values. For
people with either overly soft/acidic water or ones who need more
alkalinity and higher pH there are gravels that can help elevate both
of these.
Conclusion
As you can see there are many things to
take into consideration when deciding on
decorating your tank and this presentation
has only touched the very basics of it.
There is so much more that could and
should be said, but I hope to be able to
provide more information at a later date.