Hello; From time to time a post shows up suggesting that a member’s tank is overstocked. The ultra low stocking numbers suggested do not always fit with my aquarium keeping experience. I have kept healthy tanks with stocking densities high enough to be cited as overstocked by some on this forum. Until last spring, I kept ten tiger barbs, five serape tetras, four cherry barbs, three kuhli loaches, four cory catfish, and four zebras danio going well in a 20 gallon long for well over two years.(Note - the picture in my signature is of this setup.) I still have nine of the now very large tigers, four of the serapes, three of the cory catfish, the four cherry barbs, and the three kuhli in a 55 gallon. (The zebras are in another tank.) These fish are all now at least three or more years old. I now have space for the larger tank, but was not able to have it in my former home.
In the last couple of decades I have trended toward minimal stocking myself. It requires less effort and diligence on my part. Maybe the question can be presented along the lines of what is an idealized best on the ultra low density stocking side versus perhaps what you can just get away with on the very high density stocking side. I previously suggested picturing stocking densities in terms of walking down a very wide path versus walking along a tightrope. With low density stocking the path is wide enough for occasional problems to not be devastating. If the power goes off for several hours, low density tanks may allow for enough oxygen diffusion at the water surface to keep the fish alive. An overstocked tank may become critical before long. Think of very high density stocking as walking a tightrope. Small problems may turn into a crisis sooner. If you do not notice a dead fish right away, the decay of that fish might push water conditions that are close to the edge into being unhealthy and result in the demise of more fish. Can higher stocking densities be sustained over time? Sure, depending on your skill level and attention to the conditions.
When I joined this forum, reading thru several posts about the very low density stocking levels suggested struck me as overly conservative. (Many still do.) There is not a question that ultra low fish densities are healthy and stable, that is not an issue. Stocking at very low levels is a safe way to go and should help avoid some problems, but it is not the only way to go. I guess I am writing this because I have kept fish at much higher densities over long periods of time. My current stocking densities are lower than in the past, but even so will now be considered overstocked by the standards cited in various posts on this forum. How, for example, was it determined that a ten gallon tank can only hold six zebras as stated in one post in the past? I have stocked a ten gallon more densely several times.
When I posted similar comments in the past, a question was raised about whether my fish thrived at the higher stocking levels. Here are some relevant portions of my earlier response; “If by thrive you accept the following; 1) Grow to maturity. 2) be colorful and active throughout life 3) reproduce healthy off spring. 4) Eat vigorously 5) Be free of disease 6) exhibit traits normal for the species and the like. Then yes, I will state that fish I have kept at higher densities have thrived. Again it is not that ultra low densities are not great. That is not what I am asking about. Why not suggest ten gallons per zebra? That would surely be excellent,” “A tank can be overstocked to the point of being unhealthy, but it seems to me that some suggested densities are moved several orders of magnitude from good toward an idealized excellent. My experience suggests that they are too conservative, not that they are wrong. If I had the space and money, I would have huge tanks stocked very lightly simply because they are so much easier to run over time than the smaller tanks.” “In the wild there will likely be tens, hundreds or thousands of gallons of water per fish along with the expansive natural cycles that condition the water. We try to accommodate fish in tanks that cannot approach these levels. We substitute filters, water changes, equipment, and regular maintenance.”(I also add knowledge and experience.) “Hello; I agree with the comments indicating that it is best for new hobbyist to start out slow and under stocked, as it will take them a while to learn.”
In the last couple of decades I have trended toward minimal stocking myself. It requires less effort and diligence on my part. Maybe the question can be presented along the lines of what is an idealized best on the ultra low density stocking side versus perhaps what you can just get away with on the very high density stocking side. I previously suggested picturing stocking densities in terms of walking down a very wide path versus walking along a tightrope. With low density stocking the path is wide enough for occasional problems to not be devastating. If the power goes off for several hours, low density tanks may allow for enough oxygen diffusion at the water surface to keep the fish alive. An overstocked tank may become critical before long. Think of very high density stocking as walking a tightrope. Small problems may turn into a crisis sooner. If you do not notice a dead fish right away, the decay of that fish might push water conditions that are close to the edge into being unhealthy and result in the demise of more fish. Can higher stocking densities be sustained over time? Sure, depending on your skill level and attention to the conditions.
When I joined this forum, reading thru several posts about the very low density stocking levels suggested struck me as overly conservative. (Many still do.) There is not a question that ultra low fish densities are healthy and stable, that is not an issue. Stocking at very low levels is a safe way to go and should help avoid some problems, but it is not the only way to go. I guess I am writing this because I have kept fish at much higher densities over long periods of time. My current stocking densities are lower than in the past, but even so will now be considered overstocked by the standards cited in various posts on this forum. How, for example, was it determined that a ten gallon tank can only hold six zebras as stated in one post in the past? I have stocked a ten gallon more densely several times.
When I posted similar comments in the past, a question was raised about whether my fish thrived at the higher stocking levels. Here are some relevant portions of my earlier response; “If by thrive you accept the following; 1) Grow to maturity. 2) be colorful and active throughout life 3) reproduce healthy off spring. 4) Eat vigorously 5) Be free of disease 6) exhibit traits normal for the species and the like. Then yes, I will state that fish I have kept at higher densities have thrived. Again it is not that ultra low densities are not great. That is not what I am asking about. Why not suggest ten gallons per zebra? That would surely be excellent,” “A tank can be overstocked to the point of being unhealthy, but it seems to me that some suggested densities are moved several orders of magnitude from good toward an idealized excellent. My experience suggests that they are too conservative, not that they are wrong. If I had the space and money, I would have huge tanks stocked very lightly simply because they are so much easier to run over time than the smaller tanks.” “In the wild there will likely be tens, hundreds or thousands of gallons of water per fish along with the expansive natural cycles that condition the water. We try to accommodate fish in tanks that cannot approach these levels. We substitute filters, water changes, equipment, and regular maintenance.”(I also add knowledge and experience.) “Hello; I agree with the comments indicating that it is best for new hobbyist to start out slow and under stocked, as it will take them a while to learn.”
