Shrimp Guard and Intake Guard: How to Stop Shrimp and Fry From Getting Sucked Into Your Filter

Shrimp and fry get pulled into filter intakes because the intake is just an open tube. Nothing about a stock canister or lily pipe intake knows the difference between water and a baby shrimp.

A guard fixes this by covering the opening with something water can pass through but a shrimp cannot. This guide covers why it happens, what keepers already do about it, and how to size a guard instead of grabbing a generic one.

Why shrimp and fry get pulled into filter intakes

A canister filter or a lily pipe pulls a steady stream of water through its intake. A shrimp or a fry is small and light. Get too close to the opening, and the pull is stronger than the animal can swim against.

Adult shrimp usually have enough size and strength to stay clear. Shrimplets and fry do not. A tank built for breeding almost always has more small, weak swimmers in it than a typical community tank, so the problem shows up fastest there.

DIY fixes people already use (sponge, pantyhose, zip ties) and where they fall short

Fishkeepers have been solving this problem without buying anything for years. The most common fix is a foam pre-filter sponge slipped over the intake tube. Another is a piece of pantyhose or fine mesh held on with a zip tie or rubber band.

A few dedicated products exist too. Fine stainless mesh guards for lily pipe intakes are sold in Europe in a couple of fixed sizes. Some hang on back filters ship with a foam guard already built in.

None of these are sized to your exact intake. A sponge loose enough to slide on is also loose enough to work off over time. Pantyhose stretches, tears, and looks improvised. The European mesh guards come in fixed sizes that may not match a US filter or a US sized lily pipe at all.

Sizing a guard to your intake, not a generic one-size mesh

Our shrimp guard is sized to fit over a 16/22mm barb, the same size used by an Eheim Classic 600 intake and several other canister models. It slides on the same way an adapter does, snug, no glue.

The slots are cut into the cage wall. Water moves through easily. A shrimp or a fry cannot fit through the gap.

Slot width is 1.5mm. We fit-tested this slot width by hand and it passed our check. Watch your tank after you install it anyway. No guard is a substitute for watching your tank.

Shrimp guards on lily pipe intakes, not just canister intakes

Canister intakes are not the only place this happens. A glass or PETG lily pipe intake pulls water the same way, and shrimp keepers ask about guarding lily pipes just as often as they ask about guarding a canister hose.

We are designing a lily pipe inflow set with the same slotted cage built into the tip. It is not for sale yet, we are still fit-testing it. Until it ships, our standalone guard covers a bare intake hose the same way.

What we do and do not promise about livestock safety

We print every guard in PETG. It is the material aquarium keepers have used submerged for years.

We cannot promise a guard will stop every shrimp or every fry in every tank. Slot width, water flow, and the size of your animals all play a part, and we do not control all three. Watching your tank is still the best protection you have.

Rinse the part in clean water before it goes in your tank. That is a simple step, and we ask it on every printed part, not just this one.

Frequently asked questions