How to Catch Fish in a Saltwater Aquarium

Sometimes the the need arises to remove certain fish from your saltwater aquarium.  Perhaps they’re being a bully, taking bites out of coral, needing to be moved to a quarantine tank due to illness or are just getting too big for the tank.  

In my case, when I bought my new Reefer XXL625, all the fish had a growth spurt.  Going from a 80 gallon (300 litre) to a 133 gallon (550 litre), gave them more room to swim and therefore grow. 

I had never had a problem with my wrasse living with the two fire shrimp and they did so happily for years.  Suddenly she was big enough to nip the lower bodies off both shrimp while still alive.  They did not survive so, unfortunately, she had to go.

4 Ways to Catch Saltwater Aquarium Fish

Catching any fish is no easy task.  I resorted to using a manufactured fish trap for my wrasse so I know this method works (see video below).  

Here are a few methods that reefers have successfully used to catch saltwater aquarium fish: 

1. Disorientating fish

You might want to try this method first as it certainly won’t cost you anything.  Fish are way more active in the day so doing this at night will give you the advantage. 

A few hours after the lights go out in your tank, quickly turn them on.  This will disorientate the fish and make them easier to catch with a net.

2. DIY fish trap

A DIY fish trap is very simple to make and can be made using items found at home or bought cheaply from a dollar store.  Two great methods shown in these videos are: this DIY fish trap that uses a jug and this one that uses a soda bottle.

3. A manufactured fish trap

Acrylic Fish traps like the this, are a great way to catch aquarium fish.  There is less chance of the fish being harmed and reduces stress to other fish which could be chased around when trying to catch them with a net.  

Large Fish Trap for Aquariums/Acclimation Box
  • 9 1/4 x 6 1/4 x 6 1/4 inches
  • 100% highest quality laser cut acrylic of 3/16 thickness
  • Adjustable and detachable hanging brackets with removable feeder included

Place the fish trap in the tank at night once the lights are off.  The fish will be wary at first but will soon get used to it being there and not posing a threat.  Feed fish their normal food through the feeder for a few days and they will soon start venturing in and out of the trap.  

Once you see the fish you want to catch entering the feeder regularly, stand by ready to lower the door.  It would be a good idea to practice releasing the door before actually trying to trap the fish.  This is so you know how hard to pull the string when the time comes.       

4. A net - but not the way you think!

This one may take a bit of time but is a really clever way one reefer found of catching fish.  The idea is to feed fish from a net.  And this net is the one you can eventually catch them in. 

Feed the fish as normal and quickly scoop up the fish you want to remove from the tank.  It may take a while but the fish will eventually associate the net with food and make your job easier when it comes to catching them.


You don’t have to spend a lot of money on a manufactured trap so give the others a go before spending your hard earned cash.  Unless you want to of course!  As I showed in the video, it does work. 

Hi, my name is Craig.
I am the owner of The Salty Side.
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4 Ways to Catch Fish in a Saltwater Aquarium