Is my tank over stocked?

only6foot6

AC Members
I currently have a 37 gallon tall tank. I currently have 5 congo tetras, 3 scissortail rasboras, 2 ottos, 2 glass catfish, 3 pristella tetras, 1 red serpae tetra, 1 black skirt tetra and 1 yo yo loach, for a grand total of 18 fish. Do you think this too many fish or perhaps the opposite?

One thing that I have noticed is that most of my fish hang out between the mid to upper levels of my tank. With this being the case, I have a lot of activity at the top but relatively none at the bottom.

If you have any ideas or suggestions, I will be happy to hear them all.

Thanks!!!
 
I think that you might want to provide enough fish for a school of some of your tetras, but I don't think that there is enough capacity in the tank to add too many. Removal of some fish and then addition to the remaining schooling fish would be a good bet. As for bottom dwellers, I will suggest Cories and Otos. They're my personal faves for the bottom of a tank, but I am sure that you will get other suggestions.
 
The problem is the mention of the 37g high tank. This greatly reduces the amount of gas exchange which could happen without some subtantial aeration and thus agitation of the surface. I agree that there is room for a few more fish, but not too many due to the lowered amount of gas exchange.
 
The number of fish means nothing without considering size. For example, my 12" pleco produces a lot more waste than a school of 8 1-1/2" cardinals.

Whether or not you are overstocked also depends on how much filtration you have and whether or not you're concerned about what will happen in a power outage. I.e. if the power goes out, your filter and heater will turn off - but more importantly, there will be virtually no surface disturbance, which is what dissolves the oxygen your fish breathe.

Also this is more of an art than a science. You will hear people say one inch of fish per gallon of water, one inch of fish per 10-12 square inches of surface area, or whatever. Those are good guidelines, but you can fool yourself into thinking you're not overstocked if your fish survive because you have good filtration and the power doesn't go off for long.

Max size x number of fish = Inches of fish
5 congo tetras = 15" of fish
3 scissortail rasboras = 15" of fish
2 ottos = 4" of fish
2 glass catfish = 8" of fish
3 pristella tetras = 6" of fish
1 red serpae tetra = 2" of fish
1 black skirt tetra = 2" of fish
1 yo yo loach = 5" of fish

Giving a total of 57 inches of fish in a 37 gallon aquarium.

That is a lot more fish than I would be comfortable with in my aquarium. However many people would be comfortable with this, and maybe even put more in there. Like I said, if you have good filtration and don't have any extended power outages, you may be fine. If the power goes out for any significant length of time, you're probably going to have losses.
 
Good reasoning and explanation Heady, I fully agree.

To me the tank is overstocked, but it is sustainable with good filtration and good maintenance so long as there are no problems. If problems arise with power outage, high temperatures, disease, etc., the slippery slope is steep and fast.
 
i say you have room for a few more but advise add some that hang out at the bottom all the fish you have like the upper level of the aquarium.
 
Thanks, plus a little more info

Thank you everyone for your advice. I really appreciate everyone's input.

Heady, thank you for the nice breakdown chart regarding fish type vs. maximum size, you brought up some interesting points.

I am currently using an Emperor 280 power filter for my tank. So far, I have been happy with its results. I do not use an air pump but the Emperor creates a nice water movement at the surface.

I also forgot to say that my tank is planted with Java Fern & Anubias. I know this also helps improve the water quality of the tank.

Thanks Again
 
Most of those maximum sizes were obtained right here from aquaria central; for the ones that aquaria central did not list, I checked at least 2 different websites before settling on a size. Whether fish are actually kept healthy enough to reach their maximum size is another story.
 
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