The Fairy cichlid

Biotoecus opercularis “Rio Uaicurapá”. Photo by Reef to Rainforest.

Biotoecus opercularis, or the fairy cichlid as it’s often referred to because of its very small size, is a South American species from Brazil. Maxing out at about 1.5 inches, this tiny cichlid is not very common in the hobby nor is it overly colorful. However, like many other dwarf species, its attraction is in its behavior, especially when spawning.

Reef to Rainforest just released a short piece about the species along with a fantastic video. Check it out!

Interview follow-up

Back in early May, I posted a follow-up about getting an interview with Dr. Henrique Varella of the University of São Paulo, Brazil. If you’re not familiar with him, you should Google him. He’s a prolific cichlid researcher who has formally described several new South American species.

Anyway, I communicated with Dr. Varella at the end of March and thought the interview was forthcoming. However, I have not heard from him since then, despite several attempts to reach him. Therefore, I’m guessing the interview is not going to happen. I’m disappointed because I was optimistic and really hoping to bring you a great interview about his work and his latest species discoveries.

If something changes, I will provide an update.

Filter media bags

Filter media bags. Photo by author.

If you’re running a power filter, do you use filter media bags? If not, maybe you should. There are more reasons to use a media bag than there are not to. I’ll give you a few.

Flexibility: If you want to experiment with different media or you have several favorite brands/types you want to try in combination, using bags allows you to explore nearly any kind of loose media (biological, chemical, and mechanical). Yes, you can use sponges to “secure” loose media such as plastic bio balls, ceramic rings, and others within the filter baskets. However, if you use products such as loose carbon, zeolite, polymer resins, peat, or even crushed coral in your filters, you’ll learn quickly why you need media bags.

Time: If you often exchange the media in you filter, preloading a bag can be a big time saver. When it’s time to clean your filter, swapping bags takes seconds. I’m obviously not suggesting you remove all of you colonized media and replace with fresh. However, you can remove some of it and replace with new. It will colonize quickly. Furthermore, if you’ve ever tried wrangling loose mechanical or bio media, it can get irritating. If you have a canister and you drop a tray of loose media, you’ll wish you had been using a bag. Same goes with loose media in the basket of a HOB or other power filter.

Cleaning: It can be much easier to clean media in a bag than it is to clean them loose. Whether you use tank water or tap water to rinse your media and whether you rinse under running water or in a bucket, manipulating the contents of a bag is much easier. Grab the bag, shake or knead it under the water, and you’re ready to go.

Seeding media: If you have a tank with an overflow reservoir and you don’t want to rob your existing filter of colonized bio media, drop some bio media in a bag and put the bag in the overflow. You will have seeded media whenever you need it. See my post from last year on seeding media in an overflow.

Your LFS should carry a variety of filter bags. If not, you can find nearly any size online at Amazon or other retailers. Some people use pantyhose, and there are other DIY options. Whatever you choose, consider using bags in the future. I think you’ll be glad when you do.

Deciding whether to buy juveniles or adults

When purchasing fish, deciding whether to buy adults or juveniles might seem simple at first thought. However, you should probably think about it a little bit. Why? Because the answer should really depend on why you want the species and what its value is to you.

Unless you’re infinitely familiar with the species you’re buying, how do you even know if it’s an adult or a juvenile? For example, Neolamprologus brevis are very small cichlids, or dwarf species as we call them. A full grown adult brevis at ~2.5 inches is smaller than juveniles of many other species.

You should also consider the species lifespan. Some species live much longer than others. Furthermore, many species aren’t sexually dimorphic until they’re adults. In other words, you might not know for a while what gender you have.

Using the brevis example, if you go online and purchase a full grown adult, you really have no idea whether that fish is a year old or three years old (unless you’re an expert on brevis). So in terms of value, unless you can determine the age of that full grown adult, how do you know whether you’re buying a fish that, assuming it’s healthy and will live its normal life span, will live for four months or three years? I don’t know about you, but I don’t want to pay $15-20 for a fish that might well die of old age in four months versus paying the same price for one that is only a year old and has several more years to live. Thus, if I can’t really determine the age of the fish once it’s an adult, I’m better off buying what I know is a juvenile. So back to the brevis example. If I don’t know much about that species, but I know for, say $10, I can get either a 1/2″ fish (which would be a juvenile) or a 2″ fish (which would be an adult), what makes the most economic sense?

There are certainly exceptions to this. For example, if you’re wanting to breed a species immediately and it’s a species you don’t currently have, you’ll want to purchase adult fish. But even then, you have to be careful. A female cichlid’s fertility and even fecundity typically decrease as she ages. So knowing exactly how old the fish is might still matter even if you know it’s already reached breeding maturity.

These are just a few of the factors that you might consider when you decide to buy a fish.

Removing algae from rocks

I regularly encounter fellow cichlidophiles who are perplexed when it comes to cleaning algae off the rocks in their tanks, including holey rock. There are many different ways to rid your rocks of algae buildup, some more labor intensive than others. If you’re not in a hurry, the easiest and most tank friendly way (no chemicals used) is to simply sun bleach them. What does that mean? Just put them in the sun for a few days. Afterward, they’ll look as good as the day you got them. How many days depends on the volume and type of algae covering the rock.

The photos below show two holey rocks covered in green algae and the same rocks after three days in the sun.

Algae covered holey rock. Photo by the author.


Sun bleached holey rock. Photo by the author.


Sand substrate decisions

Image from

So you’re thinking of swapping your gravel for sand, or you’re starting a new tank and want to use sand for the first time. Regardless of the scenario, you want sand in your tank but you aren’t sure what kind to use. The answer to that question lies with the type of fish you have, how much you want to spend, and other factors.

There are many sand varieties and types available and usable for the aquarium hobby. Just like anything else related to the hobby, you should do some basic research before deciding on which kind of sand you choose.

There are numerous brands of aquarium sand such as Carib Sea, Nature’s Ocean, Aqua Terra, Imagiterium, National Georgraphic, just to name a few. But you don’t have to use sand specifically sold for the aquarium hobby. Many hobbyists use play sand, pool filter sand, and even blasting sand. So what’s the right sand for you?

Answer these questions:

  • Is/are my tank(s) glass or acrylic (acrylic scratches easier than glass)?
  • What kind of cichlids will occupy the tank(s) with sand (e.g., sand sifters, New or Old World cichlids)?
  • Do I need a pH and hardness buffering sand mix (e.g., do you have neutral or lower pH source water or soft water and need to change it based on the question above)?
  • What color of sand do I want or will work best with the cichlids I want to keep?
  • How much sand do I need (a good rule of thumb is 1-2 lbs of sand per gallon)?
  • What is my sand budget?
  • How easy is it to get the sand I want (e.g., via my LFS, other local store, online)?
  • What kind of filtration will the tank(s) have (yes, some people still use under gravel filters, which don’t work well with sand)?

Once you have a good answer to those questions, you can begin narrowing down what will work best. If you’re more familiar with sand substrates and not a complete novice in the hobby, I would recommend that you investigate the use of non-aquarium sand (e.g., pool filter sand). One trade off with these types of sand is cost versus silica content. Non-aquarium sands are typically much less expensive than the aquarium specific varieties. However, some of these sands contain higher concentrations of silicates and other elements, which can exacerbate diatomaceous algae issues and create other problems. Also, aquarium sands often have much finer granularity (i.e., the sand particles are smaller) than non-aquarium sands, which is nearly analogous to comparing powdered sugar with regular sugar.

There is a ton of online information available on sand substrates for cichlids. I would encourage you to do some leg work and see what other hobbyists use and say about their sand choices. To do that, you may need to join a cichlid forum or cichlid FB group and simply read posts about choosing sand, types of sand, etc. Fellow hobbyists are some of your best resources for additional information about the hobby. However, fellow hobbyists also share advice that is simply wrong, so tread with caution when visiting such sites.



Filtering good and bad advice

Image from

I’m guessing most readers of this blog fall into two camps with respect to cichlid keeping – those who know very little about it and those who have lots of experience. This post is directed at members of the former camp.

As you work to build up your knowledge base on the hobby, you’ll probably seek out information from multiple sources. One of those may well be Facebook. I can not stress enough the importance of learning from authoritative sources. Facebook cichlid groups can be a great place to get quick answers to many questions and solutions to many problems. However, Facebook is also loaded with ill informed individuals and trolls, who provide bad information.

Today’s example of bad advice comes directly from a comment to a post about sand getting into the impeller of HOBs. The poster is a novice aquarist who asked for some advice on preventing his fish from kicking up sand into the intakes of his HOB. Thankfully, he received some solid advice. But he also received some head-scratching input. One commenter suggested changing the filtration to sponge filters, which is certainly valid. However, in response to that comment, there was this little nugget from either a troll or someone who should do more reading about the hobby and less advising:

Sponge filters should only be used a [sic] supplementary. You still want to have some sort of power filter.

Sigh. Often times the filtration of choice comes down to four factors: tank size, knowledge, preference, and budget. Nonetheless, suggesting that sponge filters should not be used as primary filtration is simply incorrect. As was adeptly pointed out by someone who saw that comment, entire fish rooms are often filtered by nothing more than air driven sponge filters.

So what is my point with this post? Unless you know the source of the information and you trust that source, crosscheck what you read to ensure accuracy. Don’t automatically rely on advice you get from social media.

Why do you keep cichlids?

I asked myself that question the other day and, surprisingly, I didn’t have an immediate answer. That’s because I actually had several answers, which prompted me to write them down and compose this post.

In no particular order, here are a few reasons why I keep them.

  • Diverse behaviors –  Parenting, predation, mating, eating, and territorial defense are just a few of the behaviors that vary greatly from species to species. Furthermore, aggression levels run the gamut from completely docile to out right hostile.
  • Diverse personalities – Yes, each species shares certain innate behavior, but each individual specimen has its own personality.  These can vary just like in other pet species – dogs, cats.
  • The challenge – Not all cichlid species are easy to keep or breed. There is always a species that presents a new challenge.
  • Lot of choices – With so many different species available in the hobby, there are plenty to choose from to fit my preferences. This includes choices in size, color, behavior, cost, water requirements, etc.
  • Opportunities to learn – I’ve been in the hobby for 20+ years and I’m still learning new things.
  • Fun to watch – Many species are simply fun to watch.

How about you? Perhaps you have some other reasons, which I hope you will share.

Interested in Gymnogeophagus gymnogenys?

Gymnogeophagus gymnogenys. Image from

For those South American cichlid enthusiasts out there, especially those fond of eartheaters, John Carlin at Fincasters recently posted a new episode where he interviews Imperial Tropical’s Mike Drawdy about Gymnogeophagus gymnogenys. This is a beautiful substrate spawning, mouth-brooding cichlid found in Uruguay, parts of Argentina, and parts of southern Brazil. It’s a great interview and very informative, especially for hobbyists unfamiliar with the species. You can view it here. The specimens Mike has on display in the video differ in color from the above, but that’s not uncommon.

If you want to learn more about Imperial Tropicals and Fincasters, see the interviews I did with Mike and John, respectively: Mike Drawdy interview, John Carlin interview. I would also encourage you to visit their respective websites.