Interview with Don Zilliox

 Don Zilliox

Not long after beginning in the hobby, I took a determined path toward keeping and breeding cichlids. My interests originally focused on colorful dwarf species of Central and South America. Very quickly I was starving for knowledge, having already consumed nearly every monograph and magazine article I could get my hands on. It was then I began reaching out to the experts.  One of my very first contacts was a kind gentleman by the name of Don Zilliox, otherwise known as Z-Man in the aquarium hobby. I can’t count the number of times I e-mailed him with questions. He responded to every e-mail and was quite patient with me.

A quick Google search for Don will yield a plethora of links to all kinds of information about cichlids. He has written numerous articles covering a variety of dwarf species, including Ctenopoma ansorgii and Crenicichla regani. He’s also written a great piece about keeping and breeding Apistogramma in general. Through decades in the hobby, he has bred more than 100 species. Suffice it to say, he has forgotten more about fish keeping than I’ll probably ever know. I recently got in touch with Don, who has mostly retired from fish keeping. He was gracious enough to answer a few questions for the blog.

Continue reading this post…Interview with Don Zilliox

Log that data!

When it comes to pretty much any maintenance activity that involves my tanks, I always take notes. Whether it’s adding/removing fish, testing the water parameters, doing water changes, or anything besides feeding the fish, I always write down what I did. Why? Many reasons.

The day will come when something will go wrong in one of your tanks – water problems, livestock issues, etc. Rather than trying to rely on memory as to what you might have done or not done to contribute to the problem, often times a simple check of your notes will reveal the issue.

Do you remember how many of those black skirt tetras you added as dither fish three months ago? Do you do a dfc (dead fish check) nightly, such that you’ll quickly recognize one is missing before his carcass becomes so decomposed that he blends in nicely with the substrate?

Or how about noticing that your pH has been slowly rising with each water change and subsequent test?

There are lots of reasons to take good notes about your maintenance activities. Use whatever method works best for you. I’ve used a pencil and little notebook (or several of them) over the years. Now I use a nifty little app on my Macbook called Evernote. Though not specifically for logging aquarium data, it’s a great tool for keeping, storing, and searching notes of all types. Trust me, over time you will come to realize the value in keeping notes on your aquarium activities.

Cichlid exporting

If you’ve ever wondered how wild caught African cichlids are collected for export, it can be pretty low-tech. Wild caught cichlids from around the world are prized in the hobby as breeding stock. Often referred to as F0 in cichlid offspring parlance, wild cichlids are typically adults and are most often sold by fish importers/breeders. F0 doesn’t always mean the fish was taken directly from its native habitat, however. F0s might also be labeled as such if they’re pond raised near watefront breeding stations. In any case, here is some good introductory information about the African cichlid exporting business.

For more video footage of Lake Malawi and cichlids, visit the African Cichlid Hub.

Water Testing

IMO, responsible aquarists monitor their water parameters by testing periodically, and proper water testing requires good test kits. I’ve used digital meters and reagent test kits over the years. Both are effective, and each has its place in the aquarist’s toolkit.  I currently use APIs test kits. Your local fish store (lfs) should carry them. If not, they’re readily available online.In order to understand the parameters of your tank water, you should understand the parameters of your tank water source. To that end, you should test your source water, whether it’s municipal or well water, as well as your tank water. If you get all your water from a local fish store, check that too. If you filter your own water (municipal or well), make sure you set a baseline for the filtered water and its source before it’s filtered. Changes made to any of these sources can affect the water parameters. The pH of water can change from one point of origin to the next and can also change over time (e.g., the pH of recently generated RO water will change over time in a storage container).

To be comprehensive with your testing, you should check levels of Ammonia, Nitrite, Nitrate, pH, Carbonate (KH) hardness and General (GH) hardness, and Phosphate. The API master test kit (shown at top) consists of a couple of test tubes as well as liquid reagents for testing Ammonia, Nitrite, Nitrate, and pH. Phosphate is a separate kit, so is the kit for testing the two hardness parameters. Combined, these kits will total four or five test tubes. You can purchase extras at your lfs or online.

Below is a test tube rack I purchased to help keep my tubes together and to facilitate their drying. The photo on the left is looking at the rack straight on. The right photo is looking down from above. The rack has two rows, one with spindles to invert the test tubes on and the other row contains hole slots to set the tubes down in. You will notice three syringes (left in left photo – syringe tubes in front row and accompanying syringe plungers in the back). You can pick syringes up at medical supply houses. I use these because they each hold just a bit more than 5ml, which is the volume of water each of the API tests requires. I bought the rack online for about $8.


Photo courtesy of the author – Scott Wells.


Photo courtesy of the author .


Photo courtesy of the author.
Understanding your water and how its parameters can change will help you diagnose problems when they occur. For optimal fish keeping conditions, nothing replaces regular, frequent changes of water in closed systems (e.g., aquariums).

A new aquarium


Image from ClipArt Best.

Little brings greater joy to an aquarist than getting a new tank. I ordered a new 55g aquarium that just came in. For many cichlid keepers, a 55g tank is quite small. Remember, however, that I keep dwarf cichlids. Thus, this tank size is quite reasonable.

For me, there is always some trepidation with a new tank. Lots of thought should go into setting up a new aquarium, regardless of your experience level. Even though I’ve done this many times, I still think everything through with respect to a new set-up. In fact, I still make a checklist. Below are the questions I ask myself before setting up a new tank.

  1. What species of cichlid(s) do I want to keep?
  2. How many of the species do I want to keep?
  3. What other tank inhabitants do I want?
  4. What size tank, at minimum, do I need for adults in #2 and #3 above?
  5. Will I keep live plants?
  6. What kind of lighting do I need?
  7. What kind of substrate do I need?
  8. What kind of filtration do I need?
  9. How do I plan to heat the water?
  10. What kind of shelter do I need based on #1 above?

There are other questions I could ask that aren’t as critical, such as do I want to use an airstone, do I want to cover the top of the tank at all or leave it open, etc. Of course the answer to many of these questions leads to more questions (i.e., if I want live plants, what kind?).

After I’ve answered the above, I now have to think about the timing. Why does that matter, you ask? Ahhh, another set of questions. Below are a few.

  1. Do I have to cycle the new tank or do I have mature, colonized media ready to go?
  2. Where will I get the species I selected in #1 of the first checklist above? If my local fish store (lfs) has them in stock, then I can proceed. If I have to order them, I have to find a seller that has them. 
  3. Where will the new tank reside in the house?
  4. Do I have to move anything to set it up?
  5. Do I have electrical outlets nearby?
  6. Can I control the ambient light in the room?

I’m not obsessive compulsive, but I’ve found that thinking about all of these things before setting a new tank up can greatly reduce the likelihood of a headache that often results from poor planning. Perhaps you have your own checklist.

Plants in the aquarium

Having had many fish tanks in the past with live plants, I have to say there is something magical about them. They help create an authentic aquarium biotope. A heavily planted aquarium full of a variety of beautiful fish is quite a spectacle. However, live plants have always presented problems for me.

Just like an aquarist needs to be committed to maintaining a healthy environment for his/her fish, the same can be said for maintaining a thriving planted tank. I guess my commitment hasn’t been strong enough because I can never keep plants alive for long periods of time. Except for a single anubias that I bought nearly a decade ago, which is still alive and growing, nothing else has survived longer than a few months. I suppose having a green thumb doesn’t apply exclusively to successfully growing terrestrial plants.  

In my opinion, heavily planted tanks like the one in the photo above are not easy, and I applaud those who maintain them. I’m convinced that there are too many components required to do this well – correct lighting, fertilizer, CO2, appropriate water parameters, etc. I’m also convinced every plant I’ve ever purchased came with an unseen bonus gift – snails. Trumpet snails are a nightmare. All things considered, I think I’ll stick with either no plants or a few artificial plants for color, decoration, shelter, etc. 

Having a conscience


Image from

I was on social media today and came across an interesting thread. A fellow aquarist recently acquired a tank that is 24″ x 24″ x 24″, which holds roughly 60 US gallons of water. He asked the following of his fish keeping peers: “Would this be big enough to house a single large cichlid?”

My first thought was, how is he defining “large cichlid”? My second thought was, why would he even consider housing a cichlid in a tank that only has two feet of swimming space glass-to-glass?

Every hobby has novices who deserve the opportunity to learn. However, at some point, common sense has to be a guide. Furthermore, a conscience needs to also be part of the equation.

Tank options declining

So I’ve been thinking about replacing one of my existing tanks. My 55g, which has been running continuously since 2000, is due to be replaced. Two of the larger aquarium brands, Aqueon and Marineland, offer a pretty comprehensive selection of tank configurations for retail. However, the industry is moving away from aquariums with oak color trim. Higher end and custom built glass tanks come in a wide array of wood grained trims, including oak and cherry, but most of the retail offerings are exclusively black trimmed.

Because I have a nice oak stand with the 55g footprint (48.3″ x 12.8″), I actually have several tank size options. Stock aquariums with the same footprint as the 55g include the 33g long and 40g long, so there are options. However, oak trimmed varieties are difficult to come by from my local aquarium store. I don’t want to put a black tank on an oak stand and the existing stand is too nice to paint. Fortunately, my local shop found a supplier that still had one 55g in oak remaining.

I bought it.