Aquarium Gardening Notes

Beta at Play: My First YouTube Video

The One Inch of Fish per Gallon Myth

A few  days ago, a fellow hobbyist emailed me with the sweeping statement that the One Inch of Fish per Gallon Rule is - and I quote - "truly wrong". I emphasize "truly" and can just imagine the gavel in his hand.

To his credit, see picture on left. This is a snapshot taken in 2004 of one of my 40 gallon planted breeder tanks, shown here with a plethora of healthy Red Platy. The aquarium had over 100 Platy fish. Fish were healthy and plants too. They would swarm the front glass like a hive full of bees every time I showed up to feed them. Without any predators to speak of, they reproduced freely from an initial purchase of just four fish.

I eventually gave a large quantity of these fish to a University of Wisconsin aquatic project. I gave another large quantity to a local pet store before dismantling the setup.

So, why am I writing this post, and more precisely, why do I still try to adhere to the One Fish per Gallon Rule? Not being a scientist or an expert hobbyist, I simply think that this rule is an excellent rule of thumb for my tastes.

#1: It sets a cap on my impulse to purchase additional fish I don't need.

#2: Aquariums are rather small systems. It is only reasonable that these finite living quarters have a threshold. Not knowing what this limit really is, I'm of the opinion that limiting the amount of fish, fish detritus and fish food is a good idea as far as limiting strain on the aquarium's ability to process waste and sustain life.

#3: My main goal is to grow aquarium plants, not breed fish. Although my large troupeau of Platy fish was an interesting experiment, I prefer the beauty of freshwater plants. A 100+ fish in a 40 gallon tank means you end up watching fish more than the greenery.

Angel Fish Attempting to Breed

Wanted to mention that my Angel fish regularly attempt to breed in the 35 gallon tank. This usually happens a couple of days after a water change.

First, I notice them tending a large sword plant leaf. Usually they eventually proceed to laying eggs on that plant. Up until the last occurrence, I had never witnessed this laying of eggs. It had always happened at night.

Both fish partake in this process. One lays eggs and the other hovers directly over them. I suppose it has to do with fertilization? I don't know. I should read up on it. They take turns in the ritual. This time, they kept at it all afternoon.

Once that dance is over, they "fan" the eggs and protect the area from wandering fish. The only other fish in the aquarium is a Betta and a handful of red Platies. Those other fish don't seem curious about the Angel nest anyway.

Usually, the eggs disappear withing a couple of days. I can't figure out what happens to them. Perhaps the parents gobble them up? On this particular occurrence, the eggs remained on foliage for two days and then the parents started picking at them.

Soon I observed the parents trying to position the eggs on the aquarium wall a few inches above the nest. They would take the eggs in their mouth and spray them onto the wall. They kept doing this over and over until the microscopic eggs would attach themselves. Those wall-attached eggs wiggled, as if they were some kind of larvae. The parents kept protecting them until they disappeared. Again, I have no idea why they just vanished. Perhaps they were eaten by the parents or perhaps they got loose and were sucked into the filter. I have no idea.

A community tank with a powerful filter is probably not the ideal place to raise Angels. It would probably be better to pair off Angels in an isolated aquarium with no filter. I am not in the business of breeding fish, so that's where my interest stops for now.