Monster Tank

Monster Tank



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 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 part!.

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 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 photo).

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...

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