You’ve Bought a Tankbuster! Now What?

Queen Angelfish (Holacanthus ciliaris) will outgrow the aquariums of most hobbyists

Queen Angelfish (Holacanthus ciliaris) will outgrow the aquariums of most hobbyists

At one time or another in their fishkeeping career, many marine aquarium hobbyists make the mistake of purchasing a fish that is destined to grow too large for their tank. They may do so completely unwittingly (because they didn’t research that “pretty little fish” in advance), or they may be more or less aware of the species’ growth potential but underestimate how much tank space it truly needs in order to thrive.

Regardless of how hobbyists manage to make this blunder, they’re left with the problem of what to do with the fish now that it’s in their aquarium and growing fast. If you should find yourself in such a predicament, here are a few possible solutions to explore. I’ve listed them in the order of (in my opinion) best to worst options.

Upsize your tank

It may be that the fish in question is a tankbuster only with respect to your current aquarium. For instance, that harlequin tuskfish may prove to be too much fish for your 75-gallon, but if you have the wherewithal to upsize to, say, a 125-gallon, your problem is solved and your fish will be much better off for it. (Not to mention, you’ll have a new 125-gallon tank!) Of course, keep in mind that if you have a spouse, partner, or roommate sharing your living space, such an arrangement may warrant pre-approval for the sake of domestic tranquility.

Reach out to fellow hobbyists

If upsizing your tank isn’t a viable option, another alternative would be to look for a suitable “adoptive parent” among your fellow hobbyists. The solution to your conundrum may be a simple matter of finding someone who has a larger system that isn’t already maxed out in terms of bioload and has an interest in the species in question.

If you’re a member of an aquarium club or society, that would be a great place to start. You can also put the word out on internet forums to see if anyone bites. Your LFS may even be able to connect you with another hobbyist who might be interested.

Prevail upon your LFS

Speaking of your LFS, if you bought the tankbuster there, you may be able to prevail upon them to take the specimen off your hands. However, I wouldn’t get your hopes too high. Many stores have a policy against this, as they don’t want to risk introducing disease from home aquarium systems to theirs and/or they don’t want to waste valuable sales tank real estate on overgrown fishes that most hobbyists can’t accommodate. Even if your LFS is willing to take the fish back, keep in mind that they may or may not refund all/any of your cash.

I should emphasize that if you’re a regular paying customer (not a perennial looky loo) at the LFS and have made the effort to nurture a good relationship with the dealer, he or she will be much more likely to work with you in such circumstances.

Try a public aquarium

I’m hesitant to even include this as a viable option because public aquariums are inundated, virtually on a daily basis, with requests from hobbyists to take fish specimens that have grown too large for their tanks. It’s very rare indeed that these facilities can actually accommodate such requests. However, if all else fails, it might be worth at least a phone call or email. If all the stars just happen to be in alignment, perhaps you’ll luck out and they’ll have room for your specimen or at least have a suggestion for whom to call next. But again, don’t get your hopes up!


If you enjoyed this post, subscribe to get our new posts in your email.
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. Paul Baldassano says

    I have given quite a few fish to public aquariums but as you said, they are reluctant to take them. I once had a cute little remora that was about 2″ long. In a couple of months it grew to about 9″ long and after a while I could only fit his head in the water. I gave it to the NY Aquarium where he probably grew another five feet long requiring the Mayor to raise the taxes to feed the thing.
    I also collected a cute little burrfish that grew very large and I gave him to a public aquarium on Long Island.

  2. GREAT article…so true! We always recommend to our customers that they do their research on the new finned friends that they are considering (before they buy!) However, we also feel it’s important for the LFS to ask questions and make sure their customer is about to purchase wisely 😉

    Works for us!
    thanks for writing these great articles

    • Thanks so much for your kind comments, Nancy! You’re absolutely right that if both the hobbyist and LFS ask the right questions, far fewer tankbusters will end up in undersized tanks.

  3. Even if the aquarium or LFS won’t take it back they may know somebody who would. I’d say ask everybody you know. Lol

    • Jeff Kurtz says

      That’s true, Canille, Even people who aren’t in the hobby may know someone who is, so it’s worth turning over every stone, so to speak. Thanks for sharing!

  4. Oliver Giesler says

    I returned a large Pretoris Volitans to it natural enviorment from where I captured him as a baby trust me it still knew ho to hunt.

Leave a Reply to Oliver Giesler Cancel reply