Reptile & Amphibian Forums

The general rule of thumb I have always used when stocking my tanks is 1 inch of fish per gallon of water. But I have heard that you can increase the carrying capacity of a tank. Is this true? And if so, how do you achieve it?

Thanks!

The 1 inch of fish per gallon rule is out. There is no general rule currently, you just need to do the research of the fish you want to keep. A good place to start is Badmans tropical fish website (which I've given you below). The minimum tank size is listed for the individual species.
You really can't increase the carrying capacity because there's only so much space and oxygen. Even if you added an air stone and live plants, you would still run out of swimming space. Also, the with more fish you would have more ammonia which is the number one fish killer, and it kills fast. If you put more fish in the tank, you would need to do more water changes which would stress your fishes out. This could lead to serious diseases. However, when I figure out how many of what fishes I can have in a certain tank, I still want to provide an air stone or two because with tropical fish the water temperature has to be warm, which doesn't hold as much oxygen. I always give them more oxygen because with more than one fish not only are they competing for space, they are competing for oxygen.

Does this answer most of your questions?
Badmans fish

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Phishie

"An ounce of prevention is worth a pound of cure."

Your response was definately helpful. Thank you.
I'm wondering though... Since the old rule it out... I have a 46 gallon bow front. Currently there are about 46 inches of fish in there. According to the old rule, this is enough fish. But, a lot of my fish population are cat fish and loaches who don't really take up "swimming space" at the top and middle.
Will powerheads and an extra filter benefit my tank? Or are they pointless to add? I do 25% changes about once a month, usually doing a 5% or 10% change in between the monthly maintainence. I use a good quality water conditioner and I also add a bacteria supplement when ever I do a change. Could two, larger water changes (ie. 25% changes every other week) be beneficial? Or would smaller, more frequent changes be better?
I certainly don't want to stock my tank to the point of the fish bumping into each other. I just want to make sure I'm not overloading what the tank can safely handle in terms of waste.
Thanks again for all the help.

I would still say you have an overstocked tank because even if your upper levels aren't occupied with the loaches and catfish, they are still competing for space in the lower region, and they are still producing a lot of waste products. Luckily for them, you seem to be pretty good with water changes. I would say you should be good with whatever filter you have, but it is necessary to do water changes at least 20% biweekly. I read somewhere that it is less stressful for the fish if you do changes every week (low percent changes - maybe 5%, but to be sure of what percent you can always test your water to see what your water parameters are every week until you see a cycle for your individual tank) because your fish will then be used to your hands being in the tank as well as any foreign objects you use. Any water changes that are over 20% biweekly can be harmful to your beneficial bacteria. Also, doing only one water change a month is bad. If you haven't had any fish die off yet, I'd say you are doing well, but only if your tank has been set up for longer than 6 weeks.
If you haven't had any fish die off yet, you are probably doing a good job of removing wastes. Since you already have your tank set up, and purchased the fish, I would just suggest that you keep a close eye on the water parameters (ammonia, nitrates, and nitrites,etc. - the three I mentioned are most important). I wouldn't add anymore fish to the equation though.
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Phishie

"An ounce of prevention is worth a pound of cure."