Facing a Saltwater System Downsize? Try One of These 5 Setups

Yellowhead Jawfish (Opistognathus aurifrons) are on my short list for the impending tank downsize

Yellowhead Jawfish (Opistognathus aurifrons) are on my short list for the impending tank downsize

Next year, our daughter will be heading off to college and our son will already be well on the way through his senior year at OSU. With two kids almost down and none to go, my wife, Melissa, and I will soon (more or less) be empty-nesters. It also means we’ll soon be selling our two-story, four-bedroom home and moving into something better suited to a twosome and a few occasional visitors.

Of course, talk of downsizing our house has led to several discussions of downsizing my 125-gallon aquarium to something more manageable and what form of setup that might take. Below are just a few of the ideas I’m mulling over. If you happen to find yourself in a similar situation—or you’d just like to take on a different sort of hobby challenge—you might want to give one of these setups a try as well.

1. A nano reef

I’ll lead with the most obvious option: a nano reef. Generally described as a reef system smaller than 30 gallons, a nano reef can fit in virtually any living space with room to spare.

As I’ve pointed out in various posts in the past, the biggest challenge of nano systems is their greater instability when it comes to temperature and other water parameters relative to tanks holding larger volumes of water. Of course, the confined space also significantly limits the number and size of specimens you can keep and presents special issues when it comes to specimen compatibility.

Nonetheless, the burgeoning interest in nano tanks has led to the development of all manner of nano-appropriate gear, making this facet of the hobby more accessible and achievable than ever before.

2. A single-specimen oddity tank

Here I’m thinking along the lines of an Antennarius sp. frogfish (such as Antennarius striatus). I’ve always been a huge fan of these odd little anglers, which are unrivaled when it comes to camouflage and boast amazing anatomical adaptations that they use to lure prey. They also don’t need a great deal of swimming space, so perhaps a 30-gallon tank housing one of these cryptic characters or a similarly sized oddball would fit the bill.

3. A yellowhead jawfish colony

I know, I know, I’ve brought this idea up about a thousand times but haven’t gone through with it yet. Perhaps that will change with our future move and I’ll finally set up my Opistognathus aurifrons colony. Granted, I would need a tank of at least about 40 gallons with a relatively wide footprint (i.e. a breeder tank) along with a deep, mixed-particle-size sand bed for a small colony, but that would still represent a decent downsizing from my current 125-gallon.

4. A seahorse system

One of my wife’s suggestions is a small tank dedicated to a group of captive-bred seahorses, specifically dwarf seahorses (Hippocampus zosterae). I’m not sure how I feel about this, as these little critters pack a lot of demands into a very small package, but H. zosterae can certainly be kept in very small systems and would be a good option for a dedicated, experienced hobbyist who’s up to meeting these demands (i.e., providing a constant supply of small live foods in the proper concentration, exceptional and stable water parameters, etc.).

5. A clownfish/BTA tank

A tank dedicated to Entacmaea quadricolor (the bubble-tip anemone, or BTA) and a pair of one of the many clownfish species that it’s known to host would make for a fascinating, manageably sized display. As with the jawfish colony, I couldn’t do this in a nano system, but I could get by with, say, a 40-gallon breeder. What could be more iconic?

What would you do?
As always, fellow salties, I’d love to hear any suggestions you might have. So what setup would you choose in my situation?


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About Jeff Kurtz

Jeff Kurtz is the Co-founder/Editor of Saltwater Smarts, former Senior Consulting Editor for Tropical Fish Hobbyist Magazine, and the aquarist formerly known as “The Salt Creep.” He has been an aquarium hobbyist for over 30 years and is an avid scuba diver.


  1. Hi,
    if I were downsizing I would go for a species-specific tank, such as pipefish. These are very interesting and possible breeding can take place. Or I would try my hand at bangaii cardinal breeding. Just my thoughts….
    Good luck!

  2. Once you have your new home I would simply consider a suitable space and location for a tank, You might just be surprised at what size tank you can accommodate and perhaps an ideal position for it will present itself. Only then would I make my choice

    • Hi Les! Keeping the current tank may or may not be an option, depending on how the sale goes. The Toledo real estate market never really recovered from the economic crash, so we’ll be lucky to break even on the sale, let alone make any money beyond what we owe. That means we may have to spend a few years renting a small apartment or condo to accumulate a down payment for our next home. We’d stay put in hopes of a rebound, but signs don’t look hopeful and there’s always the possibility that the local market will drop even further. Keeping my fingers crossed!

      • I understand your predicament Jeff and sympathise with you and your situation, obviously I was not fully aware of all the circumstances. I wish you good luck on whatever you decide along the sale of your home and in finding a new one. Hopefully it will all work out for you sooner rather than later. .

  3. Matt Bowers (Muttley000) says

    Hi Jeff! If I had to pick one I’d go for the colony of Jawfish. Mostly drawn to it because I think the personality of an already cool fish would be multiplied exponentially in a colony setting. Dwarf seahorses could be a real challenge for a couple wanting to get out of town for a few days on vacation or to see the future grandkids!

    • Hi Matt! That’s kind of how I’m leaning too. Besides, I’ve been all talk and no action on that project for long enough. Thanks!

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