Fish Fetish

One of my fish has disappeared, again. They do this from time to time. I never see the bodies anymore. Haven’t in years. There is too much in the tank to ever see a body, they just disappear.

I have never written about my tank in my journal, mostly because from the time I started this journal it has been in my parent’s basement while I finished school and looked for a job. It is still there—the difference now is that so am I. Since I have never talked about it, and I have nothing better to talk about now, I’ll explain my tank, my own personal fish fetish.

First of all, it’s not really a fish tank though that is what most people would call it. It is really a Reef Tank. Meaning that while it has fish in it the main attraction, at least to me, is the “other” stuff. The coral, shrimp, starfish, crabs and other more exotic life in the tank are what I like. There are some fish that I like in it, mostly ones that are small, and live in the rocks.

My tank has been up for five years now. It’s 75-gallons of salt-water with a 20-gallon sump tank, 88 pounds of live rock (rock from the reefs around Fiji) and 100 pounds of crushed coral to cover the bottom. This all adds up to roughly half a ton of water and rock. There are also a bunch of pumps to move water around and a huge light fixture which houses 4, 55-watt Power Compact lights—each light puts out 4 times the light of a regular 4-foot florescent. 2 lights are white, and two are blue, because blue light penetrates water better if you remember your physics class you will remember why.

Most fish tanks have some kind of mechanical filter on them, they tend to hang on the back of the tank and, in one way or another pass water through charcoal and mesh and other filtering material. The only external form of filtration on my tank is a Protein Skimmer, a device to take help take solid waste out of the water—the solid waste is dissolved and the protein skimmer used tiny air bubbles to float it out. Ever been to the beach early in the morning and seen the foam at the tips of the waves as they crash into the sand? Same thing, just nature’s immense version of it. The protein skimmer is really just a clever system of pipes and air tubes. A pump pushes water into the large vertical tube where it mixes with tiny air bubbles. As the air pushes to the top it passes through a bottleneck. Solid matter gets trapped on the top of the rising bubbles forming foam (more physics and a little chemistry!)

Inside the tank the real filtration takes place, see the protein skimmer takes out the solid matter that’s in a certain size range, but bigger stuff falls to the bottom and deteriorates and really small stuff just passes through the skimmer and breaks down. What happens to it all when it breaks down? I won’t bore you with the details—you’ve already had them once, back in biology class, it’s called the nitrogen cycle, look it up. Bottom line, nasty chemicals build up and must be broken down so the fish do not die from the toxicity. This is what the hundred pounds of crushed coral and eighty-eight pounds of live rock come into play. See the reason for the live rock, the reason it’s called live rock, is because of the stuff living in it. Most importantly, the bacteria living in it.

This bacterium builds up in the rock and the crushed coral over time, and its job is to break the nasty chemicals down into not so nasty chemicals, thus making the water good for the fish and corals. The bacteria are good at this that once the tank is established there is very little cleaning required. In fact a well-established reef tank needs less cleaning than most goldfish tanks. Every couple of weeks I stir up the crushed coral and take about ten gallons of water out of the tank and replace it with ten gallons of clean salt-water. Other than that the only thing is to feed the fish and coral (oh yes, you have to feed them too, they don’t live totally off light—they need calcium and a few other things) and I also spend a few minutes cleaning the algae off the glass once a week. Of course there are lots of little problems that come up over time, but if you do the maintenance very rarely does anything serious happen. Mostly a fish gets sick now or then, which is usually a sign that you need more maintenance or did something wrong. And every time you put a new fish, coral, or other in the tank things can go wrong—they die from being moved, they fight with what’s in the tank already. It’s the growing pains of a tank.

My tank has had its share of growing pains; sudden coral die offs—I lost half my coral in one week and never found out why. Fish jumping out—I gave up on Diamond Watchman gobies after four jumped out in less than three months, and the first one was in the tank for six months before he jumped out! Then there are aggressive fish, three of my oldest fish seam to want to beat up any new ones I put in the tank.

Right now I am a little short on coral, never really recovered from the die off as I was at college at the time and not there to buy coral. I have some nice coral, but need more. As for fish, the new ones seam to die off but the old ones never do. I have one fish that has been in the tank since the beginning—five years ago! Four more that are more than three years old. I have a starfish that has been there for almost five years and a oyster that is almost as old.

The biggest problem now is that I am board. Every time I put something new in it dies, or it is just a replacement for something that died. The fun of a reef tank is in setting it up and stocking it, sitting in front of it for hours looking at the things you just put in it, every fish, every coral, every crab or snail is different and unique and getting to know then is the fun. I would take everything out and start over, but I don’t have the money. When I get a job and a place to live I have to take the tank with me. I think I will just take it down, give the fish to the fish store and sell the tank. Then when I am settled into a new place I’ll start over, from the ground up so I can get to know new fish and coral, new crabs and snails.