How to Get Rid of Scuds in a Shrimp Tank: A Complete Guide

Scuds, also known as side-swimmers or gammarus shrimp, are a common pest in shrimp tanks. While they can be beneficial in small numbers, an explosion of scuds can wreak havoc in your tank. They compete with shrimp for food, and attack vulnerable baby shrimp. They also munch on delicate plants.

If you have an out-of-control scud population, you’ll need to take action. In this comprehensive guide, we’ll cover everything you need to know to get rid of scuds in your shrimp tank.

What are Scuds?

Scuds are a type of small freshwater crustacean There are over 200 species in the gammarus genus They are omnivorous bottom-dwellers that feed on decaying organic matter, algae, plants, and small invertebrates.

Scuds have a lifespan of 1-2 years. They are prolific breeders, producing dozens of young every few weeks. Their rapid reproduction is why scud populations can explode in aquariums.

How Do Scuds Get in My Shrimp Tank?

Scuds are adept at hitchhiking their way into tanks. The main ways they sneak in are

• On new plants – Scuds attach themselves to moss and other plant roots and leaves. When you add new plants to your tank, you may inadvertently introduce scuds as well.

• With feeder fish or shrimp – Scuds can come along for the ride when adding new livestock to your tank. Always quarantine new additions to prevent introducing pests.

• Through shared equipment – If you borrow tools or decorations from another aquarist, scuds can transfer over on these items.

• From their own tank – If you culture scuds as fish food, some may escape and get into your display tank. Use a tightly sealed culture container.

How Do I Know if I Have Scuds?

Scuds can be tough to spot because of their small size and ability to hide. Here are some signs that you may have scuds:

• Missing baby shrimp – If newborn and juvenile shrimp seem to disappear overnight, scuds are likely the culprits. They attack vulnerable molted shrimp.

• Damaged plants – Scuds chew holes and shred delicate plants like moss. You’ll see ragged edges on leaves.

• Food swarming – At feeding time, you may notice a swarm of tiny critters crowding the food. This frenzy is a sign of scuds.

• Visible scuds – With a flashlight and close inspection, you can sometimes spot scuds darting around plants and the substrate.

Are Scuds Harmful in a Shrimp Tank?

Scuds are opportunistic omnivores. In small numbers, they can be beneficial clean-up crew members. But when the population booms, they become problematic for shrimp tanks:

• Eat baby shrimp – Scuds attack vulnerable young and freshly molted shrimp. This hampers breeding efforts.

• Compete for food – A horde of scuds can steal food intended for shrimp. Lack of food stresses shrimp.

• Damage plants – Scuds munch on tender plants, especially moss. They can destroy carpet plants.

• Take over tank – A massive scud population dominates the tank. Shrimp may become stressed and die off.

Keeping the scud population under control is crucial for a healthy shrimp colony. Let’s look at the best ways to get rid of scuds.

How to Get Rid of Scuds in a Shrimp Tank

Eliminating every last scud is difficult. Focus instead on reducing the population to a non-threatening level. Here are effective methods:

Use a Trap

Traps allow you to catch scuds passively without having to dismantle your tank. Some popular options are:

• Shrimp traps – These cylinder traps have small slots that scuds can enter but not exit. Bait the trap with an algae pellet or shrimp pellet. Place traps on the substrate in the evenings when scuds are active. Collect and discard the traps in the morning.

• Bottle traps – Cut the top portion off a plastic bottle and invert it to create a funnel. Bait the bottle and wedge it into the substrate so the neck points up. Scuds crawl in but can’t get out.

• DIY traps – Make cheap traps from plastic containers by cutting entry points and adding bait. Place upright or horizontally on the substrate.

Check and empty traps daily to remove scuds. Trapping works best together with other methods.

Perform Water Changes

Frequent water changes help by manually removing scuds through siphoning and improving water conditions. Do 25-50% changes 2-3 times per week during the scud purge. Use a gravel vacuum to target the substrate where scuds congregate.

Vigilant water changes improve shrimp health and reduce scud breeding. But water changes alone won’t eliminate an infestation. Combine with trapping and removal methods.

Remove Plants and Decor

Scuds cling to surfaces and hide in intricate decor. Removing items gives you a chance to eliminate scuds.

During water changes, take out all plants, wood, rocks and ornaments. Gently rinse items and use a toothbrush to scrub off scuds. Discard the rinsed water which will contain scuds.

This deprives scuds of places to hide and breed. Keep decor out for a few days before returning it to disrupt the scud lifecycle. Combine with substrate cleaning.

Clean the Substrate

The substrate harbors the bulk of the scud population. Regular cleaning and disruption forces scuds out into the open.

Use a gravel vacuum to deep clean the substrate during water changes. Target areas around plant roots where scuds accumulate.

You can also temporarily remove all substrate and rinse it thoroughly before replacing it. This labor intensive process requires removing livestock and draining the tank.

Consistency is key – frequent substrate disruption keeps scuds from gaining a foothold.

Use Chemicals or Medication

Certain fish medications contain ingredients that are toxic to scuds, like copper and formaldehyde. However, these are also harmful to shrimp.

Some shrimp keepers have succesfully used No-Planaria to reduce scuds. It contains a natural insecticide that targets scuds. Start with half doses and closely monitor shrimp. Remove carbon filtration during treatment.

Chemicals can quickly knock down scud populations but also harm shrimp. Use cautiously after researching dosage and shrimp compatibility.

Add Scud Predators

Introducing fish that eat scuds is an all-natural way to control populations. Some good choices are:

• Guppies
• Endlers
• White cloud mountain minnows
• Chilli rasboras
• Dwarf cichlids like ram cichlids

The fish should be too small to eat adult shrimp but large enough to consume scuds. Monitor closely and remove predators if they disturb shrimp. This method takes time but avoids chemicals. Make sure predator fish are compatible with shrimp water parameters.

Set Up a Separate Scud Tank

If you can catch a starter population, set up a separate 5-10 gallon tank to breed scuds as fish food. Add some gravel, plants, wood and fish food. The scuds will proliferate in the dedicated tank.

Harvest scuds daily by laying vegetable matter like cucumber slices on the bottom – scuds will swarm it. Pull out the vegetable covered in scuds and rinse them off for fish to eat.

A separate scud farm means they won’t invade your shrimp tank. It also gives you a natural food source for fish.

Preventing Future Scud Infestations

Getting rid of scuds requires diligence. Here are some tips to avoid recurrent outbreaks:

• Quarantine all new plants, fish and invertebrates for 4 weeks before adding to the tank. This prevents pests like scuds from entering the main tank.

• Rinse new plants vigorously and use a bleach or hydrogen peroxide dip to kill scud eggs and larvae.

• Avoid sharing equipment with others. If you must share, sterilize items first.

• If culturing scuds, ensure the tank has an airtight lid and cover. This stops escapes.

• Maintain optimal water parameters and plant growth. Healthy tanks resist scud takeovers.

• Perform weekly substrate cleaning to remove scud breeding grounds.

• Check under rocks and wood during routine maintenance for signs of scuds.

• At the first sign of scuds, use traps and removal methods before the population expands.

With vigilance, you can keep shrimp tanks scud-free and provide a safe habitat for your shrimp colony to thrive.

Frequently Asked Questions about Eliminating Scuds from Shrimp Tanks

Are scuds the same as copepods?

No, scuds and copepods are different crustaceans. Copepods are even smaller and harmless, even beneficial, in shrimp tanks. Scuds look like tiny translucent shrimp with large