When buying aquarium fish, many of us overlook compatibility issues. Species compatibility is as important to successful aquarium keeping as is understanding the basics of the nitrogen cycle. The reasons are pretty simple.

Every species of fish has evolved to thrive in a particular environment. While many aquarium fish species originate in tropical regions, all habitats are not the same with respect to water chemistry. In addition, behaviors that help a fish survive in a particular environment can make them difficult tankmates. Even though most freshwater aquarium fish have been raised for generations in fish farms and other captive environments, they retain many of their original needs and characteristics.

The Cichlid family is a good example. Some originate in African lakes that have hard water and a high pH. Others are from South American waters that have a low to neutral pH and soft water. Things like temperature, pH, hardness, oxygen content and most other water parameters are different in different parts of the world. So are survival tactics. Most Cichlids survive by being aggressive, while other species survive by hiding. Some fish prefer to forage at the surface of the water, while others are mid water feeders and still others are bottom feeders. Fish can also be nocturnal.

All of these things and more need to be considered when selecting aquarium fish. Even though some fish may look good together, they may not be able to live together. Certainly they don’t all need the same temperature, pH and hardness. It’s true that many aquarium fish can survive in a wide range of conditions, but for good health they need conditions very similar to the waters of their origin. Providing exactly the right conditions for a particular fish species is one of the keys to successful aquarium keeping. Perfect, of course, is rarely possible, but good enough is not good enough. That’s true for behaviors as well as water parameters.

 The next time you’re thinking about getting some new fish, do some research to find out what water parameters they prefer, how large they will be as adults, how their behavior will affect tankmates, food preferences and feeding habits, etc. Also consider whether they are fast or slow moving, if they prefer to school with others of their species, if they’re fin nippers, aggressive, passive, territorial, shy…. It all affects your success as an aquarist.

I hope this helps get us thinking about compatibility issues, and I hope to see additional examples related to species compatibility.

Today I looked through some of the older blogs and postings, and i think there’s enough material to write a book. It took at least a half hour just to scan through all the blogs; hours would be required to list all of the postings. But back to the blogs because this is a blog blog. Maybe the term is a shortened version of something like web log. Who knows?

In reading some of the blogs I found quite a few pieces related to the nitrogen cycle, different species of aquarium fish, and personal aquarium adventures. Just to make things clear, I wrote many of the blogs, but my name was put on quite a few by accident. We are, after all, dealing with computers. If the computer will allow it, I plan to convert some of the older postings into blogs, because they’re more of a permanent record about subjects that are important to aquarists.

When writing blogs, most of us have been careful to avoid publishing copyrighted materials. It’s OK to reference or summarise previously published materials, but taking a few paragraphs directly from those materials amounts to the theft of intellectual property. Sources, of course, should be named. However, just mentioning a source does not confer the right to plagiarize it. Doing so would be like stealing something and telling the world about it. So far as I know, nothing on this website is copyrighted, and nobody is watching for copyright violations. It’s just something we should all be aware of.

Finally, we’re always looking for new and easier ways to access the information on this website. If you know the title of a post or blog, the search function will find it. It also works if you’re looking for a particular subject. When it comes to computers, nothing is as easy as it seems. Our chief computer guru is working on it, and he’s making improvements all the time. If you have suggestions about making this website better, let’s hear them.

Update (by admin): The content on this site is copyrighted, and the Site Terms strictly prohibit copyright violation (search the Intellectual Property Rights paragraph), as well as our Community Rules (rule #6). Note that it is OK to quote another source and give him a reference, but it is not OK to copy entire works. You can check out a quick Fair User FAQ from the copyright office.

courtesy of danidantje

The latest issue of Aquarium Fish International had some interesting things to say about Chinese Algae Eaters. First is they are not from China, and second is the adults do not eat algae. In fact, the adults become aggressive and feed off the protective slime coats of their tank mates. That’s why a community aquarium can wind up with multiple deaths and one Chinese Algae Eater.

BTW, don’t confuse it with the gentle flying fox, which eats algea throughout their entire life, or the Otocinclus which is smaller.

Flying Fox

courtesy of threefingeredlord

Otocinclus

courtesy of Whisper Photography

To get things started, here’s a picture of my 25 tall. It’s a pretty good tank for spawning angelfish, and it takes up the same floor space as a regular 20 gallon tank. Although this aquarium shows off my complete lack of aquascaping and photography skills, it’s a well balanced habitat that has live plants and plenty of hiding places for the fish. The Malaysian driftwood pieces offer the angelfish a spawning media while slightly lowering pH. As with all of my aquariums, this one has under gravel filtering over a substrate of gravel and, in this case, Fluorite. The under gravel filtering works, because the aquarium has a minimum biological load and gets regular, partial water changes. The replacement water is treated with Stress Coat, but no other additives or medications are used. The whole thing rests on one of my home made stands, which are cheap and strong if not very elegant.

courtesy of Chee Meng Au Yong

This is not an algebra lesson, but it discusses the equal sign in an equation because = has an important thing to say about aquarium keeping. Here are a couple of examples:

1 plus 1 = 2

6X6=36

(Sorry, we don’t have a plus sign.)

Notice that both sides of an equation represent the same thing but in different ways. If you could write an equation about aquarium keeping, it would look something like this:

Good Stuff = Biological Load plus Safety Margin

The equation is pretty difficult to calculate precisely, but if both sides are not equal, or at least close, the aquarium is not going to be a suitable habitat. On the left, the Good Stuff side, you can count things like water volume, filtering, aeration, beneficial bacteria, regular maintenance, live plants, the right lighting, a sensible feeding schedule, compatible species, the nitrogen cycle, a turkey baster, algae, a good water conditioner, a syphon kit, a water test kit, etc.

Because the variables in the aquarium equation keep changing, the right side has a Safety Margin. If the Biological Load is too big, it will overcome the Good Stuff side of the equation and render the aquarium uninhabitable. A wide safety margin makes sure the aquarium system does not operate on the ragged edge, and it promotes a healthy environment for the fish and plants.

The Biological Load in the aquarium equation is everything that feeds the beneficial bacteria. It includes objectionable materials like fish and snail droppings, uneaten food, decaying plants, and bugs that happen to fall in. Most of those wastes turn into ammonia and nitrite, which will make fish very sick. But fear not. The good cooties (beneficial bacteria) will come to the rescue by eating all that garbage and converting it into plant food. What a bargain. On the other hand, if the good cooties get too much to eat, the left overs will pollute the aquarium water, and the equation will not balance.

In most natural aquatic environments, the garbage gets diluted by fresh water flowing through. In a closed environment like an aquarium, partial water changes remove some of the waste. If the Biological Load is small enough and the Safety Margin is large enough, the equation will balance, and the good cooties will not have digestive issues. Neither will the fish.

If we were scientists, we could put actual numbers to all of the variables in the aquarium equation. Then we would add up the numbers on each side to see if it balances. It has nothing to do with luck or putting one over on the rule makers. The equation is nothing but hard facts converted into numbers. When the right side exceeds the left side you will have a sick aquarium that cannot provide a livable environment to the fish. When the Good Stuff equals the Biological Load plus a generous Safety Margin, the fish will have an environment that allows them to fight off diseases and parasites, make more fish, and be easy to maintain.

The numbers have to add up, and cheating does not work. Think about it.