40 Gallon Tank Stocking

[Jim53]

Hello,

I am doing a fishless cycle on my 40 gallon tank but in the meantime i'm trying to come up with a stocking list. I am running two aqua50 filters on each end of the of the tank on the highest setting. I would like to stock my tank with the fish below and I want to hear from you guys.

Would my tank be overstocked with the following fish?

6 Black Skirt Tetras
8 Red Serpae Tetras
6 Buenos Aires Tetras
6 Glowlight Tetras
8 Zebra Danios
8 Panda Cory Catfish

 

[David1978]

Not necessarily overstocked but too busy with 5 schools of fish inhabiting the same area of the tank. I probably would do 2-3 schools of mid swimmers with cories and a centerpiece fish. Larger schools of fish usually have more natural behavior.

 

[Byron]

Agree on larger groups of shoaling species. But this intended stocking is indeed overstocking this aquarium.

We often consider (or attempt to consider) fish mass in relation to water volume and filters. But this is only one aspect of stocking, and misleading as well. The behaviours and inherent requirements of the fish species must be understood and provided for, or the effect of even a few fish on the system can be greater.

The Buenos Aires Tetra, Hyphessobrycon anisitsi, is not a small fish at 3 inches (some suggest 3.5 inches likely), and it is an active swimmer. A group of these, say 7-8, would basically fill the upper area of a 40g tank (assuming a 3-foot length). A group of cories would complete the stocking.

Black Widow and Serpae Tetras are notorious for fin nipping and must be kept in larger groups to contain this within the species (hopefully). A group of 9-12 of either or both, but not with the Buenos Aires. Cories again OK.

The glowlights are the odd fish out here, being very sedate by comparison to the activity of the other fish mentioned, and they might well be intimidated resulting in stress and poor health. I would not consider this species if any of the other three are present.

My comments above have centered on behavioural issues only. More filters cannot compensate for this in any way. But in general, having larger than necessary filters, or two of them, does not allow higher concentration of fish. Some of us went into this issue in detail in another thread a week or two back.