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Tank Log:
Selecting the Tank |
The tank decision was a big one. I knew I would have to live with the decision for some time.
My basic goal was to upgrade the current 70 gallon tank to something that
was large enough to allow my reef to grow unimpeded by tank size for some time.
I didn’t want to grow incrementally again, i.e. go to a 125 or
something which I would be outgrowing in another year, but I also didn’t want
to get into a tank that I had to mortgage the house over either.
I made up my mind early that a 180 gallon tank was
the minimal size I wanted to consider. It
has a dimension of 72”L x 24”W x 24”H.
This size is readily available in glass, which I considered a plus.
Having had both glass and acrylic tanks, I like the resistance against
scratching of the glass, but I like the lightweight, look and robustness of
acrylic. Let me clarify these
points a little further for those who are not familiar with the two tank
constructions and their major pros and cons.
Glass Tanks
Pros:
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Glass tanks are held together at the seams with RTV
glue. This is the weakest part
of the tank and there have been some reported failures of the glued seam
over time or due to improper installation. |
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Glass tanks are more susceptible to massive failures if
the glass takes a heavy hit and it shatters, or the tank is subjected to an
earthquake, etc. |
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Glass is hard to modify and drilling should only be
done by a professional or skilled hobbyist. |
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The glass in a glass tank has a greenish coloration to
it due to the iron content of the glass.
On thick glass, as used in large tanks, this coloration can become
pretty noticeable. This problem
of glass tanks can be prevented by custom ordering a tank with more
expensive ‘iron free’ front glass.
This is typically give a name such as ‘sapphire glass’. |
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Glass tends to be heavy.
Large tanks can tank 6 or more people to move. The combination of large, heavy and fragile can make moving a
large glass tank a difficult and potentially expensive proposition. |
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Glass tanks can be very picky about levelness of the
tank stand. Leaks can be the
result if the stand is not perfectly level and flat.
Tank vendor warranties may also be voided if the tank stand integrity
is in question. |
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Acrylic tanks are chemically welded together at the
seams. This makes the completed
tank a single piece with no weak seams to fail. |
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Acrylic is extremely clear, with no coloration, and
generally provides better viewing of the inhabitants. |
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Acrylic is not fragile and will normally not
catastrophically fail (shatter) due to being hit |
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Acrylic is extremely light, making the empty tank
relatively easy to move. |
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Acrylic is easily drilled, glued, etc. by the hobbyist
if so desired. |
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Acrylic is a better insulator than glass.
This can help to provide a more stable environment in many
situations. It is not
necessarily a plus if dealing with lamp heating of the water in an air
conditioned room where better thermal heat transfer through glass may help
the situation. |
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Acrylic tends to be more cost effective on larger
tanks. |
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Acrylic can be bent into any shape imaginable if the
hobbyist is willing to foot the bill. |
I have come to the conclusion that in general, if someone
is contemplating a 180gal or smaller tank, glass is probably the best bet, but
anything larger is probably better if it is acrylic. This is a broad statement I realize, but given cost
breakpoints between the two construction methods, ease of maintenance, cost of
failure on larger tanks, etc., this rule of thumb is somewhat reasonable.
180 gallons also happens to be the largest standard glass tank that I am
aware of before you must customer order the tank.
I then set out to make a final decision on the size of the
tank that I wanted. I am fortunate
in that several of my LFS have display tanks similar in size to what I was
thinking. I made the
following conclusions based on my own experience and talking to several
knowledgeable LFS owners, one of who has a maintenance business as well on a
number of large high-end tanks.
Tank Length:
I knew I wanted at least 6’ of length.
I was considering up to 8’ depending mostly on cost impact.
I also knew that equipment cost would go up considerably on the 8’
tank. The basic tank/stand cost
went up 50% in price when going from a 6’ to 8’ length, so the 6' decision
became very easy.
Tank Height:
Although I love the look of tall tanks, this is an area I needed to be
practical about. Tall tanks look
good but have several serious drawbacks. One
is that the cost of the tank goes up dramatically.
Taller tanks require thicker material for their construction and this
drives cost up very quickly. Cost
aside, the other drawback is ease of maintenance.
If you cannot get your arm down to the bottom of your tank for
maintenance, the tank will probably not be maintained properly.
This is especially true for acrylic tanks, which should really be cleaned
by hand and not with something on a stick, or magnets, for scratching
considerations. For this reason, I
decided to go with a depth of 24”. I
also do not want a DSB in the main display tank. If I were planning on one, I would have taken a look at a
slightly greater depth for the tank since the DSB can occupy a significant
portion of the tank depth. I am
considering a DSB, but it will be put in the sump or in an external tank where
it is out of sight.
Tank Width:
Here is where I started to part company with the idea of a 180 gal tank.
The 24” width sounds like a lot when compared to my current 18” tank
width, but when I compared the difference of a 24” width to a 30” widths on
tanks at my LFS’, the difference in aquascaping potential was too great to
ignore. I specifically wanted to
create 3 viewing sides and the extra depth was important to do this well.
Also, the glass tanks had corner overflows that occupied a fair chunk of
the side viewing area which I did not want to give up.
I got quotes on a 36” width, but the cost went up way too fast on that
option and I abandoned the idea. I
therefore set my sights on a 30” width. This
gives me a total of 132” of viewing or 11’, which will add greatly to the
viewing pleasure of the tank.
As I plotted and planned, I did a number of tank sketches
to see how I could fit everything in and the one below is my current planned
layout. All of my other tanks were slow evolutions over time and I was
never very happy with the final aquascaping. This time, it is my intent to start
out with a master plan from the start and everything should support that end
goal. The LR areas noted below that are not called out otherwise are
slated to be SPS corals. Subject to change, but my current plan.
Net result was the following final
decisions on the tank:
