The art of stocking an aquarium revisited...again.

Man, I hope I'm not insulting your intelligence with this post about a so-called "beginner's topic."

I am writing today about what seems to be a pretty obvious concept- stocking you aquarium. I'm looking at this seemingly worn-out topic yet again simply because in the past week, I've dealt with two different customers who had major issues with their aquariums because of what were really "basic" stocking mistakes- which could have been easily avoided. Both were what I'd consider pretty advanced hobbyists, too!

I've screwed up enough times to recognize the signs that the "bridge ahead is washed out" and I need to apply the brakes.

Of course, I've went full speed ahead into that washed out bridge before, with predictable results... Perhaps we can all use another "refresher "here! I'll throw in my two cents worth.

You ever hear that expression about "stocking an aquarium requires compromise?"

Yeah, it goes something like that. I mean, the main idea is that you can't have everything that you want in one tank. Well, duh...we get that.

You need to stock your aquarium based on the needs of the animals, the ability of you and your system to handle them, and the physical size of the system, the types of fishes, etc. We all know that if your intent is to keep big, predatory cichlids, you're unlikely to be keeping small Hyphessobrycon species characins in the same tank.

You can't keep predator and prey together without the excpected unfortunate results. Again, we get that.

However, when "the rubber hits the road", and it's time to actually put this theory into practice, it's not always quite so simple. Consider this:

I'm doing a 50 gallon Amazonian-themed blackwater tank in my home office.

Right off the bat, the loose commitment to an "Amazonian theme", regardless of how "authentically biopic" I want to make it, whittles down my choices of fish significantly. No Gouramis, Platys, Pelvicachromis, Botia, or Danios in there! Nope. But that's pretty obvious, right?



I like characins. Specifically, the ones we collectively refer to as "Tetras" and "Pencilfishes", which, although is roughly a few hundred species as far as the scientific world is concerned, really boils down to several dozen commercially available species at any given time. 

Now, most of us regard Tetras as small, peaceful little fish- which by and large, they are. However, they still have some habits which can make choosing the right combination a make or break event for a new tank. 

For example, I love Pencilfishes. Most are pretty darned peaceful, keeping their squabbles to themselves. If you keep them in a group of the same species, as I have, you have little issues with them. However, when you combine them with some of the more active little guys, like Cardinal Tetras, Neon Tetras, Rummy Noses, and the like, you can have some difficulty getting your Pencils to settle in and feel comfortable enough eating.

Yeah, right? Have you ever really observed a group of "peaceful" Neons, Pristella, or the like feeding? They "spas out", and go into a frenzy. Yeah, these little "Piranha Precursors" are pretty darned aggressive feeders, meaning that "chill" fishes like Pencilfishes will have to up their game a bit if they want to get their fare share at feeding time. Some of the more docile species might simply not adjust to the "pace" that the Tetras lay down.

I always laugh when I hear some of the smaller Tetras recommended as "dither" fishes, to bring out allegedly shy Apistos and such into feeding and socializing. Really? Would YOU jump into the middle of a frenzy at feeding time in a tank with etras? I mean, it's like those videos you see of discount stores having $50 plasma TV's on "Black Friday"- you've seen the videos- you know what happens when the doors open at midnight...


And of course, even within the Tetras, there are some that are not so nice. For example, the gorgeous Serpae Tetra is a little S.O.B. to other Tetras. They see little fishes, some with attractively-flowing fins- and can't wait to nip. Yup, they are not the nicest fishes around, despite their small size and relatively passive behavior as compared to say, a Pike Cichlid or something. 

I'm only using Tetras in these examples because they are the fishes I'm working with at the moment, but the same theories apply to virtually any community. As fans of African Rift Lake cichlids know all too well, stocking is a very important and critical part of the process, and involves taking into consideration multiple factors to assure success.

You need to take these "compromises" into consideration at almost every level of the stocking process, in my opinion. To overlook a fish's reputation for having not-so-nice manners in a"community tank" is putting everyone at risk. Not good.

So what is a hobbyist to do? Well, you need to really to consider a lot more factors in the stocking process than just "will this one fit into the other's mouth?"

You need to look at the behavior of fishes, regardless of size, right? It's pretty important to take into account the temperament of the fish on any given day. Just because a fish is "relatively peaceful doesn't necessarily mean it will work in your community tank, right? I mean, "peaceful" relative to what?

It is a seemingly simple, even obvious analysis, but I see many issues that aquarists have with their tanks- even very advanced hobbyists- which could have been avoided if only a bit more time were spent on the simple "multi-level suitability analysis" of each potential inhabitant. We often are involved in the other minutiae when setting up a new system, so that even the most seemingly "obvious" thing are occasionally overlooked!

In the end, the goal of virtually every level-headed aquarist is a harmonious tank full of beautiful fishes. The best way to achieve this is to just keep things as basic and simple as possible. Research the nuances of each fish from a variety of levels before making you stocking decisions.

I think you already know this...but I can't help but bring it up one more time!

Have fun. Be aware. Enjoy yourself.

And stay wet!

Scott Fellman

Tannin Aquatics

Scott Fellman
Scott Fellman


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