Sand Snags and Setbacks

Sand gets a lot of discussion in this house. You'd be amazed at the varying qualities different types of sand possess. When I was setting up the 150-gallon, when the issue of substrate came up, I knew I wanted to use sand, because I like it, but I also wanted to choose carefully, because though I had no particular catfish plans at the time, I knew that if I wanted to keep certain catfish and/or loaches I ought to have soft, beneficial sand for them to sift through. There are a lot of choices for sand in the aquarium, from Caribsea's Tahitian Moon sand to inexpensive pool filter sand.

I have tried keeping Corydoras cats for years with little success. I never knew why, until I realized that I was keeping them in coarse gravel tanks, where their little barbels suffer, and they are unable to do the sand sifting that they do in nature. I decided that it was easier to get appropriate sand at the beginning than it would be to change it out later, so the research began.

My dear friend, Deborah, is quite expert when it comes to catfish, and based on her research and discussion with other catfish hobbyists, regular old play sand from the hardware store (Quikrete makes it) is nontoxic, inert, and the granules are soft so they will not damage the delicate barbels of catfish. Burrowing fish and eartheater type fish will also do well with this sand.

I knew I put too much in the tank initially (it is cheap and I wanted to be sure I had enough) but as I was putting it in the cloudiness kept me from seeing how much sand was accumulating. After it was rinsed and rinsed and rinsed, and things settled, I saw that I had way more than I needed, but it looked pretty, and I figured with the rooted plants I had planned for the tank they'd need the depth, and the roots would keep the sand from compacting.

Fast forward 8-9 months, and we have some problems with this sand. It has many, many areas that are anaerobic, and bubbles are released when these areas are disturbed. These areas include those with dense root growth from Crypts, swords and other stem plants. Anytime I'd move a plant, or stir the sand in the open areas, I'd find black pockets that bubbled. Uh oh. Fortunately, there have been no problems with the fish associated with release of these bubbles, with the characteristic sulfur smell of anaerobic pockets. The death of the festivum noted earlier was not related to disturbance of the sand, and that fish death was solitary. I think more than one fish would die if toxic gas was a problem.

I have begun an ongoing project involving removing quantities of sand that are not required for plants, leaving a layer perhaps 0.75" deep- no more than that is necessary. In removing the sand, which I have done slowly over time, taking out perhaps a dishpan full at a time, the stench is profound! It smells just like low tide at the brackish bodies of water near me, which also have black anaerobic pockets in the sand. The sand coming out is black, and only the top layer has the whitish-tan color. I must lave a certain amount of sand in place for the plants, especially the Echinodorus, but I am trying to remove what I don't need.

The problem is that it has settled in places where, quite honestly, I cannot reach. I am short in stature and getting access to the back of the tank is a challenge. I need long tools to get there. There is no need for there to be 2" of sand or more under a pile of rocks or wood, so if I don't redo the aquascape completely I will continue to work on getting some of this excess out of the tank. Alternatively, I will leave things be and just remove it when I completely redesign the aquascape, since the sand beneath wood and rocks in the very back of the tank is not likely to be disturbed anyway.

Meanwhile, Deborah has provided me with a plethora of Malaysian Trumpet Snails of all sizes from her own tanks, hundreds of them, and they have all vanished beneath the surface of the sand to escape the light. She gave me some in the recent past, but we agreed that more MTS were my best hope for a compromise until I can resolve the issue of excess sand. I wonder if they will even venture into the blackened, anaerobic pockets? Will they avoid these areas? No matter - they will be helpful to whatever areas they DO occupy, and their nocturnal nature will mean they have some measure of safety from the M. festivum, Snail Slayer. I think their incredibly hard shells will protect them as well, and maybe the festivum will prey only on the ramshorns, with their softer shells.

We will see what happens. I must say that the coarser sands, inappropriate for catfish, do NOT compact, as I have used them for years in my other tanks, and do to this day. Various sands for the aquarium work great for planted and non-planted tanks, and I have no issue with them compacting or going anaerobic, though you can be sure that I am taking extra care to stir the sand in all my tanks after this experience in the 150.