10 gallon experiment with soil and sand substrate
This tank was donated to us by a math graduate student at UVM. I was using it as a quarantine tank for a cichlid of mine. In mid-May, 1996, I set it up with about 1.5"of loamy soil, peat moss and dead leaves from the yard, mixed together and covered with about 1" of fine white sand. I planted a brazilian sword plant in the tank, along with some Hygrophila polysperma and some similar Hygrophila variety that has light green veins and turns pink when it gets enough light, sold to me as "Tropical Sunset Hygro", I believe.
I added some peat moss to a filter bag, and currently have about 6 killifish (Aphyosemion bivitattum in the tank (some are babies and I can't realy count them), along with 2 Corydoras julii (very pretty fish! one has more tiny fine spots on the head than the one in this picture. The other is almost identical to the fish in this picture), and two Otocinclus. I'm thinking about getting a few more cories, because the're so cute. I also have a small log in there with a ball of Java moss growing on it (and unfortunately, some blue-green algae which I rub off and siphon out periodically), and a few small floating pieces of water sprite. I have two crypts in there, in their own little plant pots, recovering nicely from a bleach treatment, after being rescued from my other 10 gallon tank, which is supporting a stubborn crop of beard algae/hair algae.
(May 96)
This is my first experience with using a soil substrate,
and so far, it's been kind of a mess. Things in the soil are decomposing,
which is fine.. but it "burps" smelly gas sometimes, disturbing the sand
and sending small plumes of soil into the water. The water is clear
overall (yellowish because of the peat in the filter) but the dark soil
material makes the sand look.. dirty. I'm not sure if the fish care at
all. I try to change about 40% of the water once a week or two (more to
get whatever might be leaching out of the soil out of the water, than to
clean out the fish wastes, which are fairly negligable).
(August 96) Over the course of the last few months, the Hygrophila have really gone downhill. I moved the Brazilian sword into the 55 because it was much too tall for the 10 gallon tank. All of the remaining plants in this tank (Hygrophila, crypts, water sprite, a bit of Elodea) have been looking more and more sickly - the leaves have been developing small clear dots in them, which spread and rot out the whole leaf after a while. The leaves then break off of the plant, float to the top of the water, and become slimy and coated with icky bubbles. I skim the surface every day to remove the rotting leaves, but I don't know what's causing this. The crypts also have tiny clear spots, and one leaf has succumbed and turned onto a slimy almost-dissolved structureless mess. Here is a picture of the tank at about this time - you really can't see the killifish, ottos or corydoras at all!
After thinking about it for a while, I decided to remove the soil from this tank. The Killifish were also looking really unhappy (they had almost no color), and the corydoras were very inactive. I siphoned out 5 gallons of water into a bucket, and moved all of the fish, plants and decorations (a rock, a java moss covered stick, etc) into this bucket. In doing so I found quite a few tiny killifish fry, much to my pleasant surprise! I then siphoned out as much of the sand as I could without disturbing the soil too much. I dumped the remaining soil back in my yard, and proceeded to rinse the sand out, dumping the soil/mud elluent in the toilet. This was a long, tiring process that I wouldn't bother doing again, but in the end, I had fairly pute white sand again. I returned the clean sand to the rinsed out (but not sterilized) tank, and then added the fish and most of the water they were in. I filled te tank up and it was back to normal. The water was surprisingly cloudy for a day - I think the sand took a while to settle. So far, the crypts haven't lost any more leaves and the other plants are hanging in there. We'll see.
Reflections on this experience:
After reading more messages on the Aquatic Plants mailing list and thinking about future plans for substrates.. I am realizing that the proportion of sand and soil should have been roughly reversed. I think I had much too much organic material in the tank, hence the rotting sulfur smell and the gas bubbles burping up from the sand. I'd like to try a rich substrate again sometime, but I'll add a small amount of soil that is fairly low in organic material to the bottom later, and cover it with at least 2-3" of sand.. I still have no idea how people keep their soil from getting really messed up when they plant and dig up plants - I was always making little sand filled plugs in my substrate, and there were other places where the soil was almost up to the surface of the sand/water interface. Maybe keeping the layers separated is just no big deal. Anyway..
Last Updated April 24, 1997
