Below is a description of my own experimental plant tank that you too can try in your own home! ;) This article was submitted to the rec.aquaria newsgroup in October 1994, and also appears on Erik Olson's Plants page.

Plant Tank

This is a description of the experimental plant tank that I have started. It is "experimental" because I want to 1) see if I can *do* it, 2) see which gadgets have the "most bang for the buck", and 3) do all of this in a low-cost way.

Beginning at the beginning :-), here's what I did. I bought a 10 gallon tank at a local pet store for $6.99. This was one of the few out-of-pocket expenses. Actually, I used store credit from some Angelfish I sold, so it really wasn't money out of my pocket. I was determined not to spend much money on this experiment, so I scrounged around for the materials I needed. This is what I found:

The Tank

I spray-painted the back of the tank flat black to 1) keep down the algae, 2) hide the airline tubing and equipment behind the tank, and 3) make the fish and plants look better. I cut a piece out of the glass that fit the top of the tank, and then made another cut through it about 1/3 of the way in from the front. I cut a 2" triangle out of a back corner for the airlines and heater and used silicone as a hinge to connect the "door" to the rest of the top. Some more silicone was used to glue a piece of wood to the door for a handle.

The hood was next, and I made a three-sided box that is 3" deep to hold the light fixtures. The box is the same size as the top of the tank and lifts off for maintenance. I wanted to put two 15W flourescent lights in it, so there wasn't room to put a hinge on it (and I was too lazy to figure out a better design ;-). I mounted two 15W fixtures in the box that I stole from the strip light on my 125 gallon tank. I'm planning on building a hood for that one too, so I didn't need the fixture any more. The two Sylvania "Gro-Lux" bulbs were $3.99 each at a local hardware store.

Click here to see a drawing of the top and hood.

I put the lights on a 12-hour cycle with a timer I had for growing garden seedlings.

The Inanimate Contents

After boiling the peat for a few minutes to get it water-logged, I put about 1 1/2" to 2" in the bottom of the tank. Then I rinsed the sand thoroughly and layered about 1" on top of the peat. That is all I did for the substrate. I chose this Dutch-type method mainly because I didn't want to spend money on Dupla's red dirt ;-). If I have enough money someday, I think I would buy the laterite because it's probably cleaner and won't decompose like peat.

In went the rain water, mixed with some established tank water to reduce cycle time. I also seeded the small sponge filter in an established tank. It was being used for an Anglefish "grow-out" tank, which was empty at the time. I installed and set the heater for 70F.

I set up a DIY yeast CO2 generator and bubble the CO2 through an airstone. With the soft rain water, this keeps the pH at around 6.5. I measured the CO2 content of the water one day and it was about 30 ppm, which is enough so that I'm not worried about setting up a reactor or about the sponge filter bubbling the CO2 out of the water. I have not measured the water hardness lately, but it was about 3.0 KH after adding a some hard tap water.

The Living Contents

The plants I chose were those that were languishing in my other under- lighted, nutrient-free tanks. There is one Amazon Sword, one piece of Java Fern, one Banana Plant, a couple Hygrophila Polysperma, and two plants that I don't know the name of. For fish, I put in a couple Neon Tetras, hoping they would breed. I also bought an Otocinclus to keep algae in check.

Results So Far

It has been about 2 months since I started the tank. The first 2 weeks everything went fine. Then an algae bloom covered all the plants, sand and tank. The little Oto couldn't possibly keep up with the growth, so I helped him out and scraped the algae off of everything. So far, the algae has not returned with the same vigor.

The plants revived almost immediately, despite the algae covering. The Amazon Sword has already outgrown the tank and its 18" leaves lay across the top of the water. The Hygro and Banana Plant sent out numerous roots and have turned red near the tops. I have already pruned the Hygro and replanted the cuttings. The Java Fern, normally a slow grower, put out 3 new leaves at first and has since slowed down a bit. The other two plants are growing as well, and their color has darkened. Every plant is almost always covered with or streaming small oxygen bubbles.

After the initial 6-week growth spurt, plant growth seems to have slowed down. Since I don't add any fertilizers or trace elements, I assume that the plants have used up most of what was initially in there. I don't know if the peat substrate will provide that much food for the plants, especially those that do not feed from the roots, so I think my next step is to try some plant food.

The fish seem to be very content in this tank. The Neons' color has become more vivid and they have spawned a few times already. Since part of raising the fry includes a period of darkness, I haven't tried to raise the fish yet. I have been feeding them mosquito larvae and white worms, which I assume has helped them get into breeding condition as much as the tank environment has.

So, it's off to the pet store with credit voucher in hand to pick up some plant food and trace elements. I just may be convinced to try this "experiment" on a larger tank in the near future. It sure is fun to watch plants *grow* rather than melt for a change!

[Up-arrow] Back up to Bryan's home page

1