TANK-MASSIVE WATER CHANGES
By Jim E. Quarles
I think that sooner or later everyone who keeps tropical fish thinks in
terms of a real monster tank. And those that keep cichlids think of it far
more often, I am sure.
At least that's why my really monster 957.5 gallon tank came into
being! This tank was built about eight years ago, and was originally
designed to hold my albino oscars
When the very first albino oscars hit the market their price was very
high. I decided this was an price trend I was not going to miss out on. So
I designed a 3/4 inch plywood tank with just one long side viewing glass,
which as it happened turned out to be ½ plate glass.
Building this tank out of plywood was far easier than most
would think. I used regular grade "B" plywood not marine
plywood. It's the kind you can buy at any lumber supply house. One side
knot free. In building this tank I counted on my experience in having
built other plywood tanks of forty five gallon size which I was currently
using as discus breeder tanks. After cutting the plywood to size, I simply
nailed it into a box shape on the floor of my garage with ring nails. (
small to keep from splitting the wood ). When this was done I had a box
that was four feet wide by four feet high by eight feet long. Of course
with the good side of the wood facing into the tank. Now that was the easy
Next I wanted to make darn sure that the water could and would never
actually touch the plywood it self. So how do you do that? I considered
using epoxy paint.. But then decided that was not going to hold up over
the long haul with a tank this size. Next I talked with a guy who owns a
boat repair shop near me. He showed me how to mix fiberglass resin and
apply it like paint to the wood to seal it from water. He then advised me
that I should also use fiberglass cloth in the tank as well to make it
stronger and really seal the wood from the water. Well after watching him
apply fiberglass cloth and resin to boats, I bought the required supplies
and was ready to start phase II of the project.
If you have ever used fiberglass resin in a closed area, you will only
do it once without providing good ventilation to the area after that one
experience ( talk about a cheap drunk. ) ( the headache to follow).
I had failed to notice that my boat friend did all his resin work
outside or in a opened ended bay area of the building. Anyway, the first
thing was to rough sandpaper all the inside surfaces to make sure the
resin had a grip on the surface once applied. This was done one side at a
time. This was not so bad because the big area where the view glass would
go was open and you could reach through and do the work fairly well. After
each coat of resin was applied and allowed to dry for at least two days,
it had to be re sandpapered once again to remove any bubbles or rough
spots. ( Eight coats of pure resin was used ). The tank was at first
tilted to allow wet resin to run into the cracks where the wood parts came
together. This sealed the joints of wood from water very well. First the
tank would be tilted one way then next time tilted the other way until all
the cracks were 100% sealed tight.
The next part was not so easy! Strips of fiberglass cloth were cut and
shaped into a ( V ) shape and then a coat of resin was applied to all
joints were the wood came together, the Cloth was then placed in the
joints and wet through with resin and allowed to dry. The ( V ) was 3
inches of cloth on each side so that when dried, the cloth tied the two
sides together as a fiberglass bond. This was repeated five times and was
sandpapered after each application to remove any air bubbles.
By this time I was sorry I ever started the project. I had used about
two gallons of resin, and it seemed like five hundred cheap paint brushes
that were tossed away after each use. Plus I had reached the point of
hating the smell of fiberglass.
While fiberglass is great to work with once you learn how it is very
unforgiving if you make a mistake. You have a very short period of time to
correct any errors before the resin sets forever!.
Well to make a long story longer, after the joints were sealed two
layers of four foot wide fiberglass cloth was resined into place on all
the wood surfaces and sanded smooth. Oh yes, the window viewing area had
been cut with a jig saw so that the ½ plate glass would seal on an area
three inches all around the front. In other word the view was cut three
inches smaller than the glass would be all around. This allowed more than
enough Aquarium Cement to be applied to seal the glass in place
It was very important that this area where the glass would seal be
perfectly smooth with no rough spots or the glass might break from stress
due to uneven water pressure when the tank was filled.
Once all the sealing was done it was time to build a stand for the
tank! Now it may surprise you to learn that when full 957.5 gallons of
water weights in at 8,473.87 lbs. Or 4.24 tons, that is not counting the
weight of the tank it self. So building a stand took more engineering than
building the tank.
I will not go into the details of this project. But needless to say it
was more of a challenge than building the tank it self.
I built the unit so that a viewing area could be removed in a false
wall into my office and all work on the tank is carried on behind this
wall. Viewing the tank from the front it looked like it had been built
into the office wall, and for all intents and purposes it was. ( see
Once the tank was ready for the glass it took three people to lift it
into place and then apply the aquarium cement and turn the tank face down
to allow it to set. ( one week).
The tank was up righted after one week and filled half full of water
and allowed to stand for a week. This adjusted the tank and the stand to
the weight. At the end of the week, the remaining volume of water was
added. And needless to say no one walked in front of the tank when it was
first filled to the top. I roped off the area to keep people, even myself,
out from in front of it, just in case the glass were to fail.
That was eight years ago, the tank has been in operation all that time
and different filter types have come and gone. But the oscars more than
paid for the building cost in short order once the tank was operational.
In many years since it has provided a home for hundreds of discus of
all ages and types. They certainly grow fast when placed in this tank.
Currently it has a sand filter with a 1/2hp motor, and a drip through
system that automatically changes 25% of the water every 24 hours.
Oh yes.. It has never leaked a drop...