Summary
Live black worms are a nutritious, high-protein food that fish go wild for—especially Bettas, nano species, fry, and bottom-dwellers like plecos. In this guide, we’ll show you exactly how to feed live black worms to your fish, plus tips on how to keep them alive longer. Spoiler: they thrive in a tank with flow, like a pleco grow-out setup!
Why Feed Live Black worms?
Live black worms (Lumbriculus variegatus) are one of the best live foods you can offer your freshwater fish. They:
Stimulate natural hunting behavior
Encourage picky eaters to feed
Promote growth, color, and breeding
Are rich in protein and nutrients
Stay alive in freshwater tanks longer than many other live foods
Whether you're conditioning a breeding pair or raising fry, black worms make an excellent addition to any feeding routine.
How to Feed Live Blackworms to Your Fish
Feeding live black worms is easy—but a few simple steps will help keep your tank clean and your fish healthy:
Step 1: Rinse Thoroughly
Before feeding, give your black worms a quick rinse in cool, dechlorinated water to remove any debris or waste.
Step 2: Offer Small Amounts
Use tweezers, a pipette, or a feeding dish to drop small portions into the tank. Start with just enough for your fish to eat within a few minutes.
Tip: Black worms will often burrow into substrate if uneaten—so avoid overfeeding to prevent losing uneaten worms in the substrate (this is fine if you want them to live in your tank).
Step 3: Clean Up Extras
After 30 minutes, remove any worms that haven’t been eaten, unless you're okay with them living in the substrate. They can live in water, so they won't foul your tank if it has good parameters.
How to Keep Black Worms Alive
Live black worms can stay fresh for days to weeks with the right care. While some people keep them in the fridge in shallow containers, we’ve had the best success housing them in an aquarium with flow, like a pleco grow-out tank.
Our Method: Black Worms in a Pleco Tank
At Scallywag’s Fish Bowl, we keep our black worms in a grow-out tank for plecos. Here’s why it works:
Flow: Black worms need water movement to thrive. A sponge filter or gentle powerhead works great.
Oxygen: Flow also increases oxygenation, which keeps worms healthy.
Cool Temps: Room temperature works well, but avoid overheating.
Tankmates: Plecos are gentle enough not to devour all the worms at once, and any uneaten worms just keep the substrate lively.
Food: The black worms have access to the wafers and repashy we feed the plecos.
Alternative: Culture Setup
If you don’t have an extra tank, you can keep black worms in a shallow container with dechlorinated water in the fridge. Change the water daily to prevent die-off.
Best Fish for Black Worms
Live blackworms are a hit with:
Bettas
Tetras and rasboras
Corydoras and plecos
Apistos and dwarf cichlids
Fry and juvenile fish
Final Tips for Success
Don’t overfeed—black worms are rich and can foul water quickly.
Keep a small dedicated container or tank if feeding daily.
Use flow and oxygen to extend worm life and reduce waste.
Shop Live Blackworms
Ready to give your fish a treat? Check out our Live Blackworm Culture
We culture all our blackworms in-house for freshness and quality. Each portion is shipped with care and backed by our Arrive Alive Guarantee.