Holey rock revisited

If you follow the blog, you probably remember a previous post on never having enough holey rock. What that post didn’t include was any tips on selecting the “right” pieces of rock. Of course, such decisions revolve around what you want your tank to look like, what you like in holey rock, etc.

However, there are some practical reasons to be selective beyond the appearance you’re striving for in your tank. Here are a few questions you might want to answer:

What size are the cichlids you are keeping?
Do you have at least a pair of rock dwelling cichlids?
What kind of substrate do you have, if any?

In my experience, holey rock comes in two basic types – course and smooth. You’ll easily notice the difference if you see enough of it. The former variety tends to have more holes or pits. It’s also rather jagged throughout, which can pose a problem. The good news is that no two pieces are shaped the same. Just stacking a few together will almost always create numerous crevices, caves, and pass throughs. 

Since I only keep dwarf species of cichlids, holey rock with built-in holes are ideal (see images 2a and 3b below). I don’t have to always strategically stack the rock to create caves. In my experience, the smooth variety of rock tends to have the larger holes. I also use sand substrate, so I look for rock that are long and somewhat thin with “arches” on one side (see image 2b). I also like flat pieces that I can easily stack on (see image 4). I use these as my base. Many African cichlids like to dig, especially mbuna. So I like to take the rock with arches and put the arch side down on the sand. This creates natural caves, and the sand can be dug out a little making the caves larger. I will intersperse some course rock on top of the smooth rock, where fry have numerous little holes to seek refuge. 


1. “Smooth” holey rock, unique shape. Photo courtesy of the author.


2a. Top view of another “smooth” rock with a nice arch underneath and a hole on the end. Photo courtesy of the author.


2b. End view of the “smooth” rock at left (2a) with a nice arch underneath, which extends almost the length of the rock. Photo courtesy of the author.


3a. Top view of a relatively smooth top but jagged rock on the side with a nice hollowed out section in the middle. Photo courtesy of the author.


3b. Side view of the jagged rock at left (3a) with a nice hollowed out section in the middle. Note the hole all the way through. Photo courtesy of the author.


4. Side view of a nice flat piece that is smooth. Photo courtesy of the author.

That “oh no” feeling – update

Sadly, the red zebra was deceased the next day. This is very unfortunate. Upon reflection, I’m reluctant to place any/all of the blame on con-specific aggression. Had it truly been stuck in the hole, it would have struggled to remove itself, which would have resulted in physical evidence on its body. There were no physical markings on it at all – no scratches, missing scales, etc. It was just pale and seemed weak. 

I honestly do not know what happened to it. The fish appeared fine the night before and had shown no prior indication that anything was amiss.  The fact that there were free swimming fry indicates that the egg laying and incubation period had long past, and I had not witnessed any parental aggression prior to discovering it lodged in the hole. If the fish was going to get beaten to death, in my opinion it certainly should have happened well before it did, not to mention that it should have shown some evidence of it. 

That “oh no” feeling

No one knows your fish and your tanks better than you. If you’ve spent any amount of time observing your cichlids, you’ll soon know what behavior to expect when you approach their tank, feed them, perform water changes, and various other tasks in which you interact with them. For this reason, you’ll usually know something is wrong before you actually spot the problem. 

It happened to me tonight. While feeding my 55g mbuna tank, one of the three red zebras was not making an appearance. Usually the most vigorous eaters in the tank, not seeing one within a minute or two gave me that “oh no” feeling. I finished feeding the tank and sat down to watch. After about 5 minutes, I knew something was really wrong. 

Because the tank contains numerous holey rock and river rock from end to end, I naturally began moving stuff around attempting to get “eyes on” all three zebras simultaneously. I moved about 85% of the rock and still never saw more than two. 

The next step was to start removing the rock. While doing so, I thought I saw some detritus that moved funny. Then I saw them. Yep, FRY!

Okay, so that might explain part of the problem. The fry had to belong to one of the zebras because I did notice one of the zebras really getting after the other cichlids in the tank while they were all feeding, which was unusual. I was not able to sex the zebras when I bought them because they were only about 2″ TL and I hadn’t given it any more thought. Thus, I really wasn’t sure if I had a breeding pair or not. 

As I pulled the third large piece of holey rock from tank and almost had it in the bucket, I heard that unmistakable fluttering sound of a fish’s shake. I turned the rock over and, sure enough, one of the zebras was lodged in a hole. It was pretty pale compared to the others, so I can only surmise it might have been in there for a while. 

I successfully dislodged the zebra once I had the rock back in the tank, but it was swimming very slowly and gingerly. It was still pretty pale after a minute or two.

Though the largest of the three zebras, my conclusion is that this was the subdominant male who was beaten up pretty badly and simply ended up in the hole.  Either that, or it was driven there and had become stuck. The former hypothesis makes the most sense, though it happened pretty quickly. Less than 24 hours prior, all three zebras were actively swimming and eating. 

About 10 minutes after extracting the zebra from the hole, I noticed it lying sideways on the sand at the back of the tank. I thought it had expired so I brushed its tail with my finger. It righted itself and slowly swam under a rock. I don’t have a quarantine/hospital tank set up and can’t get one set up until at least tomorrow. I suspect it will be too late by then but I will check on it in the morning and see if it survived the night. 

Associate tank boss

Cichlidophiles know very well that tanks containing multiple cichlids will invariably have a tank boss. This will be the apex cichlid, the one that none of the other cichlids can bully, but it won’t necessarily be the largest in the tank. Among other things, who the boss becomes will depend on the mix of species in the tank and their genders. 

My 75g is no different. It’s a mixed Tanganyikan tank that, at present, contains 5 different species of cichlids (A. calvus, N. leleupi, T. vittatus, C. macrops, J. marlieri), three species of dithers, and a couple of species of bottom dwellers. The tank boss is a male Altolamprologus calvus, one of three calvus in the tank (2m, 1f). However, I’ve discovered that the tank has an associate tank boss…and it’s not a calvus. 

Below is a photo of the associate tank boss. What he lacks in size, he makes up for in tenacity. He just generally has a bad disposition. As far as I can tell, he hasn’t really carved out a territory. He just roams the tank doling out cichlid justice to pretty much anything that crosses his path. He’s not killed or injured anyone yet, but he’s certainly sent the entire population in a panic when he zeros in on someone…except the boss calvus. 


>Neolamprologus leleupi. Photo courtesy of the author.

Show your fish!

The ACA has started a monthly photo contest and it’s open to everyone, non-members included. Get your favorite cichlid photos together and send them in. Prizes are awarded for the top three. Visit the rules page and show everyone your fish!

I submitted my T. vittatus below.


Telmatochromis vittatus. Photo courtesy of the author.

Out of sight, easy access

As your collection and variety of commercial fish foods increases, so does the space required to store them. If you’re like me and favor organization over clutter, there are plenty of low cost options to address the storage of your growing supply of flakes, pellets, cubes, etc.  

My show tanks all sit on wooden cabinet stands with storage underneath. Each of the stands has doors to conceal under-cabinet filters, supplies, and such. For the longest time, I would put my flake and pellet containers on top of the tank but that soon began to look cluttered and disorganized. It also became a greater hassle when I had to remove 15 containers before I could remove the glass canopies. 

My solution to this was to pick up a few Rubbermaid wire baskets. These are very inexpensive (< $4 each) and easy to install (each one requires two small wood screws). At roughly 4″ x 11′ x 4″, they’re also the perfect size for the regular size food jars and bags. See photos below. 

I picked my baskets up at Lowe’s or Home Depot a few years ago. Menard’s also has them by a different manufacturer, and they can probably be found other places as well. 


Wire storage basket, front view. Photo courtesy of the author.


Wire storage basket, top view. Photo courtesy of the author.


Wire storage basket, installed inside cabinet door. Photo courtesy of the author.

Shells for dwelling, breeding, and hiding

Many cichlid keepers new to the hobby often want to know what the best shell is for their particular Tanganyikan shell dweller(s). The answer to that question isn’t as straightforward as it might seem. For one, most cichlids in the hobby are captive bred, and thus shells must be introduced to their aquarium. Secondly, providing a variety of shells doesn’t guarantee that your shell dwellers will select those that are endemic to the lake.

It’s widely accepted that the shell of the Neothauma tanganyicense snail (pictured below), the largest gastropod in the lake, is preferred by most of the resident shell dwelling cichlids. It makes sense that these shells, which aren’t very large at their maximum size, would be the shell of choice. They’re large enough and abundant. However, for domestically bred cichlids that aren’t naturally exposed to Neothauma shells, it means other options are widely available. Furthermore, the shell selection process of the shellies is more a product of individual preference, and there are many variables that affect that choice, especially when breeding – ability to move the shell, the size of the female relative to the shell, etc.


Shell of the Neothauma tanganyicense snail. Photo from http://www.conchology.be/.
​I have kept two shell dwelling species of Tanganyikans – Telmatochromis vittatus and Neolamprolgus ocellatus. However, I experienced other dwarf cichlids that will seek shelter in shells, specifically Altolamprologus calvus. I bred ocellatus and, while a bit selective, they didn’t always choose a single shell species when presented with multiple options. Below are some of the shells I’ve made available to my shellies in the past.


Various shells for shell dwellers (aperture side down). Photo courtesy of the author.


Various shells for shell dwellers (aperture side up). Photo courtesy of the author.

With my N. ocellatus, I’ve had the most success using a Babylonia japonica, which is the shell at the six o’clock position above.  Lots of shellie keepers advocate for Apple snail shells, but for some reason, my ocellatus just didn’t find them attractive. A couple of the shells above are turbo species, which I thought might also be appealing but weren’t. My juvenile A. calvus would seek shelter in the Apple snail shells (the large, dark shell at the ten o’clock position above) but abandoned them once they grew too large to fit.

Needless to say, your shell dwellers may readily take to any of the shells you provide. They might also be picky and not like their choices. Shells aren’t very expensive, so you might give them at least a few options and see what works for you.

Dither thou is

Got several cichlids that are skittish or that are reluctant to come out in the open except to eat? Fear not. Many species are known to be notoriously shy, and being confined to a small space surrounded by an invisible barrier (glass walls) can produce myriad behavioral changes.

Fish react to the behavior of other fish, and those swimming naturally out in the open are often a sign that “the coast is clear” from predators, which can de-stress trepid tankmates. The same works with cichlids. Next time you’re at your LFS, pick up some non-cichlid, open water species and watch your trepid cichlids become more visible. These open water fish become what are called dithers for your cichlids. They may also make a nice addition to your tank.


Three black skirt tetras huddled together in 75g. Photo courtesy of the author.

I like to provide multiple species of dither fish, especially species that behaviorally complement each other. One of my favorites is black skirt tetras (pictured above). They are peaceful, hardy, and reasonably long lived for a tetra. They are also deliberate swimmers, meaning they don’t just swim constantly from one end of the tank to the other. They are schooling fish thus purchasing 5-6 or more is ideal.Another favorite, because they complement the behavior of black skirts, are giant danios. These are also a schooling species and are quite fast swimmers. Unlike the black skirts, giant danios are in constant motion. I’m also fond of Buenos Aires tetras – regular and albino varieties (pictured below). These are a little less active than the danios but more deliberate than the black skirts. Note the Buenos Aires at the top in the photo below. Yes, it’s missing part of its tail. Fear not. It will grow back. However, if you experience this with your own fish and your water isn’t pristine, you invite some nasty things for the fish (e.g., fungus, infection).

Yes, I recognize that the three species of dithers I list above are not endemic to the rift lakes and thus may be perceived as incompatible with the harder water of the rift lakes. I find the latter not to be true at all.


Three albino Buenos Aires tetras in foreground. Photo courtesy of the author.
I encourage you to consider adding some dither fish to your tank(s) if you have some cichlids that just don’t seem to be comfortable out in the open. Whatever dither species you choose, be sure to acquire those that are sufficient size to avoid being eaten by larger, predatory cichlid species.

John Carlin interview

John Carlin – producer and host of Fincasters YouTube channel.


If you’ve ever conducted a Web search for anything, you understand how serendipitous it can be. I unintentionally stumble across new and exciting information all the time when I’m searching for various things. It’s the same when I’m looking on YouTube for a video of some kind. In fact, serendipity is what’s responsible for this interview.

I don’t recall exactly what I was looking for, but several months ago I came across this great YouTube channel called Fincasters. Described as “…your video fish fix,” the channel is where excellent video production meets various aspects of the aquarium hobby. Who could ask for more? Covering marine and freshwater, videos range from the installation of monster aquariums to coral propagation to cichlid species spotlights.

Meet John Carlin, the man who produces and hosts Fincasters. I reached out to John a few weeks ago about appearing on the blog, and he graciously agreed.

The Cichlid Stage: How would you best describe Fincasters if you were soliciting new viewers?I would call it a video magazine.  If you think of the topics you see in various aquarium magazines, then you know what you might find on my channel and on my website. I will touch on anything from planted aquariums, to reefs, to profiles of interesting and rare species of fish, to interviews with some of the people who really drive the hobby.  I also have a section called “Tentacles” where I talk about how the aquarium hobby touches the environment.  A negative example would be invasive species, where people release their fish back into the environment (e.g., Snakeheads, Lionfish).  Positive examples would be aquarium companies helping re-build coral reefs and supporting organizations like the Coral Restoration Foundation and Project Piaba.

My blog at Fincasters.com is emerging.  It’s often more timely than some of the videos and reflects my successes, failures, and of course my thoughts.

TCS: What was the motivation or impetus for you to start Fincasters?

As you may know, my full time job is being a television news anchor.  My entire career, which started in 1983, has been shooting, editing and writing video stories for television.  I’ve also been a fish geek since I was about 7 years old, catching sunfish from the river and trying to keep them in a bucket or an aquarium.  As an adult, my son Ben and I became customers at the local reef shop, and when it came on the market, we bought it.  Eventually we sold it, keeping the maintenance side of the business.  Today Carlin Aquarium Systems is Ben’s full time job, and the business is still growing.  Our largest account is Center in the Square, where we maintain a reef system that is pushing 8,000 gallons, a 400 gallon seahorse aquarium, twin floor-to-ceiling jellyfish cylinders, and a 400 gallon Amazon predator tank.  We also raise and sell corals in the system and return 100-percent of the profits to the general fund of Center in the Square.  Those who are interested should check out http://www.Mountaincorals.org.

With the advent of YouTube, Fincasters emerged as a natural combination of my two passions.  I try to take the story telling techniques I learned in television and bring that to a YouTube audience.

TCS: Most people have no idea how much effort is required to produce quality videos like yours. Tell the readers what all goes into producing Fincasts, as you call them.I appreciate you noticing this.  I couldn’t do it unless I really enjoyed it.  It takes about 8 hours to produce a single Fincast.  Sometimes it’s less, but not often.  I spend a lot of time shooting video and sometimes working on still photography.  My recent Fincast on red cherry shrimp included some still shots I really liked, but I probably spent three hours just shooting, uploading and post producing the stills.   I’m always comparing my work on Fincasters to what we do at the TV station, where the equipment is top of the line and the staff is incredible.

Sometimes it’s hard to measure up.  I have to find a level of quality that I can live with when it comes to the video, editing, and hosting. I feel like can’t just throw something out there and be happy with it. On the other hand, it’s mostly a hobby, and I have to save some time for the actual care of the aquariums, and – my wife points out – the rest of my life.

There’s a quality/quantity equation to take into consideration.  I see lots of videos that are hand held, no special lighting or audio — with someone talking the viewer through a set up, demonstration or showing off a rare fish, and they get lots of views and plenty of “thumbs up.”  Many of these are very watchable and enjoyable.  That’s just not my style.  And honestly — I enjoy pushing the production values and sharing my information in my own way.

TCS: How do you decide the focus or subject of your Fincasts?

Usually, it’s what interests me at the moment.  If I’m on a reefing kick, then you’ll see the latest on whatever I’m adding or subtracting from my 120g reef.  Viewers seem to really like fish profiles, so I’m always looking to share information on any new fish.  Of course, I’m always looking for an excuse to bring another new fish into one of my systems.  I also have a soft spot for planted tanks, and cichlids.  I just set up a desktop jellyfish tank, so that was the topic for the last week of February.   I can tell you that my analytics suggest cichlids are the most popular with viewers.  I tend to go back and forth with respect to African vs. New World cichlids.  Right now I’m more inclined to be keeping South American cichlids.

I’m also an opportunist.  So if I go to a trade show or consumer show and someone is showing something really interesting, like a $20,000 angelfish, or a rare coral, I’ll do an interview and use the opportunity to video or photograph the fish.  Those videos are typically quite popular.

I’ve also enjoyed doing interviews with people like Rick Biro.  He grows cichlids on a farm in Florida for wholesale now, but years ago he was one of the first people to bring African cichlids to the United States.  He even named a number of them – Kenyi, VC-10, Zebra etc.  Not only does he know everything you can imagine about the various species but he has fascinating stories about traveling to Africa — (in one case not knowing he was in a dangerous area because of hippos.) finding these fish for the hobby, developing the contacts, and bringing them to the U.S.  At the end of the day, I’m still a reporter and I love it when I find someone with a good story.

PictureNeolamprologus tretocephalus. Photo courtesy of John Carlin.

TCS: Fincasters now has well over 100 episodes. What are a couple of your favorites and why?

I tend to prefer the Fincasts that deal with livestock as opposed to equipment.  A lot of people enjoy tinkering with filtration and other hard goods.  My joy comes from sharing the behaviors and habitats of the fish and inverts.  Of course, you need the right equipment and products to create those environments – so it’s always a means to an end. Having said that, videos about unique fish like the Tanganyikan Goby Cichlid or the Black Widow Frontosa are good examples.  Because aquarium space at home is always at a premium, I tend to prefer dwarf cichlids to the larger ones, so segments on Leleupi cichlids or the Dwarf Flag Acara are good ones.  On the marine side, the Pinnatus batfish video is cool, and I really like the video of the walking dendro, which is a coral that lives on a worm that pulls it around the bottom of the aquarium.

TCS: You’ve shot many episodes of cichlids, what are some of your favorite cichlids and why?

I really like discus, but they don’t like me.  More specifically, they don’t like my water.  Same for Apistogrammas.   They don’t do well long term in my aquariums, and my schedule (ok — and my personality) doesn’t permit me to stay focused on additives the way I need to be. I’m intrigued by the water parameters I’ve been able to establish with the AquaVitro Aquasolum substrate in my new freshwater shrimp tank.  There may be more discus in my future.  My current favorite cichlids are the Gold Rams and Geophagus that live in the 55g in my office.


Planted shrimp tank with Aquasolum substrate. Photo courtesy of John Carlin.

PictureNeolamprologus tetracanthus. Photo courtesy of John Carlin.

TCS: Describe the various aquariums you currently have, including those in your fish room if you still have it. 

I currently have a 55g planted aquarium with CO2 injection that has a mixture of cichlids, plecos, loaches, rummy nose tetras, and Australian threadfin rainbows in addition to a cool farlowella cat that I’ve had for several years.  The Geophagus and a single discus are the stars of that tank.

I also have a 55g planted freshwater shrimp tank, with neocaridina species such as red cherry shrimp.  I’m anxious to do more with this aquarium, as I’m new to shrimp keeping.  It’s way more engaging than I expected.

My fish room is losing a battle with my wife who wants the space for storage.  (Sound familiar?)  Right now it houses only a 20g long with a few odd cichlids.  At one point it had five aquariums ranging from 10 to 29 gallons, with various species of fish and a quarantine tank.

My 120g reef occupies a great deal of time and money.  I really enjoy the marine side of the hobby and invest a lot of time in the fish and corals in that aquarium.  And I just added a 2-gallon jellyfish cylinder to my office – which is pretty cool.

In addition, there is a Figure Eight puffer 20g high tank on my desk at the tv station.  I’m pretty sure I’m the only news anchor in America who can claim that.

PictureDwarf Flag Acara. Photo courtesy of John Carlin.

TCS: Describe your ultimate cichlid aquarium set up?

It would be a tank 6-8 feet long, 240 gallons — planted, and big driftwood — with discus and schools of South American tetras.  Big schools of rummy nose and probably cardinal tetras.  There would be several pairs of dwarf cichlids occupying other parts of the aquarium.  Apistos, Dwarf Flag Acaras, maybe Rams. There would be a school of cory catfish as well.  Not sure what species, but a school for sure.  I’ve never had a tank where I could make the cory cats school the way I have read that they do.   I really like to have a balance in my tanks with the appropriate fish in all parts of the water column.  I always need a few oddball, niche fish as well like the farlowella catfish or something you only notice in the aquarium occasionally.

TCS: Tell the readers about your next cichlid focused Fincast.

I’m pretty sure I’ll be setting up an aquarium for either discus, apistogrammas, or both.  As I mentioned above, with the Aquasolum substrate – which creates, soft, acidic water conditions  (pH about 6.8 and a KH of 0-2 and GH 1- 4 with my tap water) – I may be able to do a low tech planted tank that would make these fish happy.  I’m also looking at a 75g option for one of our clients that would be all male Peacocks/Aulonocara with lots of Texas holy rock.  This tank has the potential to be a showstopper.  The set up of this tank would make an excellent Fincast.

TCS: Would you welcome suggestions from the readers on what to cover in a future Fincast? If so, how should they get in touch with you?

I always welcome thoughts of any kind from readers or viewers.  They can respond with comments to any of my videos, follow me on Instagram (Fincasters), Facebook (Fincasters), Twitter @fincasters, or send me an email at Fincasters@gmail.com.

I’m always open to suggestions and ideas.  My only real constraint is space in my aquariums.
I’m interested in finding a way to add more tank tours to the website.  I know people have great tanks, and more and more hobbyists are able to do basic video editing.  Good cell phone video/stills are usually enough to give viewers a tour.   What does the blogosphere think?