Frozen fish and coral foods should be defrosted before being added to your aquarium. Any small container like a disposable cup or small Tupperware works well. AquaMaxx makes a dedicated frozen food strainer that works out nicely if you want to remove the liquid and just feed the food directly without a squirt feeder or bulb syringe. 

There are also in-tank defrosters like those from Innovative Marine and eShopps which actually allow you to just drop the frozen chunk of food directly in your tank. The defroster isolates the food from your fish while its frozen and slowly distributes the food as it thaws out through the bottom.  

How To Defrost & Feed Frozen Food

  1. With a thawing cup add the amount of frozen food you wish to feed your aquarium for a single feeding.
  2. Add approximately 4 Tbsp of RO/DI water per cube of food to the thawing cup. Tank water will work as well.
  3. Add any food soaks you wish to use like Selcon, amino acids, or vitamins to the cup. Let it soak for 10-20 minutes or as directed by the food soak.
  4. Occasionally stir the cup until the food is completely defrosted.
    • You can strain and dispose of any residual liquid from the food or you can also just feed the liquid food mix directly.
  5. Turn off your aquarium's filtration pumps, and any excessive water flow.
  6. Using your favorite feeding tool or bulb syringe, you can target feed your fish and corals or just pour the food into your aquarium directly.
    • Feed only what they can consume within 2-3 minutes at one time. Let the fish eat everything before adding any more. 
  7. Leftover food can be stored in the refrigerator for feeding later but it's probably not a good idea to keep the thawed food for any longer than 24-48 hours.

Learn How To Make Your Own Frozen Fish Food With Our DIY Reef Chili Recipe



defrosting mysis shrimp


Should I Rinse My Frozen Food Before Feeding?

There is some debate out there about whether or not you should rinse and strain the excess liquid from your frozen foods. The thought here is that liquid contains concentrated amounts of organic waste that won't directly benefit your fish in any way, it will only foul your aquarium water.

That said, some of those small particles of food suspended in the liquid can be a great source of nutrition for corals, filter-feeders, and other small organisms in the tank. It is also thought that the amount of organics your actually disposing of is minimal so most hobbyists forego the step of straining their frozen fish food these days when feeding a reef tank. The variety of particle sizes is actually beneficial to most tanks. 

The only situation in which it might be beneficial to strain your frozen food is when feeding a fish-only aquarium with larger particle size foods on a very regular basis. In that case, rinsing the food with RO/DI water and straining it before feeding is a logical step to take because you don't have any coral or filter-feeding inverts and could probably benefit from the reduced organic waste.