Aquarium Feeding Ring and Nori Clip Guide: Floating Rings, Magnetic Seaweed Clips, and What Each One Is For
A feeding ring is a short wall around a small patch of the water surface. You drop food inside the ring, and the wall gives that food a border instead of letting it spread across the whole tank. A Nori clip is a different part for a different job: it holds one sheet of dried algae in place so grazing fish can pick at it.
People search for both with the same words, so this guide keeps them apart. Below you will find what each part does, the three ways they mount, the sizes we print, and an honest read on what a ring can and cannot do.
What is a feeding ring, and what does it do?
A feeding ring is a wall around a patch of the surface. It does not change the food. It just marks off one spot to drop it in, so you feed in the same place every time and can watch what gets eaten.
That is the whole part. There is no lid, no basket, and no moving piece. Our rings come with a 60mm, 80mm, or 100mm clear opening inside the wall. The 60mm is the nano size and the 100mm suits a bigger tank or a group feeding.
The only real question is how the ring stays where you want it. That is the next section.
Do fish feeding rings work?
A ring works the way a wall works. It holds floating food inside a border while the surface stays calm. It is not a seal, so it cannot stop food from leaving in every tank.
Strong surface flow, a return pouring near the ring, or fish pushing at the wall will still move food around. If your surface is busy, put the ring somewhere quieter first and watch one feeding before you judge it.
We will not tell you a ring keeps every flake in one place. What we will tell you is what the part is: a wall around a patch of the surface, printed in PETG. You know your own tank's flow better than we do.
Floating ring or magnet mount: which one suits your tank?
A floating ring rides on the surface and moves with it. A magnet mount ring does not float at all, by design. A pad on the outside of the ring holds a magnet, and a second magnet on the dry side of the glass keeps the ring in one chosen spot.
Pick a floating ring if you want to lift it out and move it around. Pick the magnet version if you want the ring in the same corner every single time. The table sets the three mount styles side by side.
| Mount style | How it stays put | Suits you if | What you supply |
|---|---|---|---|
| Floating ring | A sealed air chamber runs all the way around inside the ring wall, so the ring rides on the surface on its own. | You want to lift the ring out and move it, and you do not want a magnet in the tank. | Nothing extra. |
| Magnet mount | A pad on the outside of the ring carries a closed magnet pocket. A second magnet sits on the dry side of the glass. | You want the ring parked in one spot every feeding. | Two 12mm by 3mm disc magnets. Not included. |
| Rim clip | Two legs straddle the tank wall and a thumb screw snugs the clip down. | You would rather not put a magnet in the tank at all. | One M5 nylon thumb screw. Not included. |
These are our own parts, from our 2026-08-01 build record, not sizes measured off anyone else's gear. Rings come with a 60mm, 80mm, or 100mm opening. The magnet pocket takes one 12mm by 3mm disc magnet, and the pocket is closed on all six sides so the magnet is sealed inside the print instead of sitting in the water. Magnets are never printed and never included. The rim clip opens for a wall up to about 12mm and the screw takes up anything thinner, so it is an adjustable range and not a fit claim: measure your own wall first. Today we make rings in the floating and magnet styles, and Nori clips in the magnet and rim clip styles. The floating rings are not for sale yet, because we want to hold a printed one under water and watch it before we sell it.
What is a Nori clip, and how is it different from a feeding ring?
A Nori clip holds one sheet of dried algae against the glass so grazing fish can pick at it. A feeding ring holds loose food at the surface. Different food, different problem, different part.
Our clip is a flat plate, 34mm wide by 30mm tall and 3mm thick, with two slots that open at the top. The slots sit 9mm apart. Each one measures 2.2mm across at the open top and narrows to 1.4mm at its closed floor.
The sheet is not gripped by a spring or a jaw. It is woven. You push one end down through the first slot and bring it back up through the second, and the narrowing slot lets a folded sheet wedge. That is the mechanism, stated plainly. We have not run a physical grip test yet, so check yours after you load it rather than taking our word for it.
Magnet, suction cup, or rim clip: how should a seaweed clip attach?
There are three common ways. A magnet holds the clip flat to the glass. A suction cup sticks to the glass on its own. A rim clip hangs over the top edge of the tank wall.
We make the magnet version and the rim clip version. We do not make a suction cup version. The magnet clip uses the same closed pocket as the ring, sized for one 12mm by 3mm disc, with a second magnet on the dry side of the glass. Both magnets are yours to supply.
The rim clip straddles the tank wall and takes a common M5 nylon thumb screw, which is not included. Nylon matters here: a metal screw bearing on glass is a bad idea, and a nylon one will not scratch it. The clip opens for a wall up to about 12mm, and the screw closes the gap on a thinner wall. Measure your own rim before you order.
- Fold your sheet so it is a little narrower than the 34mm plate.
- Push one end down into the first slot, from the open top.
- Bring the same end back up through the second slot, 9mm over.
- Mount the plate: magnet on the dry side of the glass, or clip it over the rim and snug the thumb screw by hand.
- Watch it for a few minutes the first time so you know how your sheet behaves in your flow.
How long should Nori stay in the tank?
Take the sheet out once your fish stop picking at it. Anything left over is just food sitting in your water, and it will start to break down.
Check the clip the same day you load it rather than leaving it and forgetting. Pull the leftover sheet, rinse the plate, and put it back when you feed again.
How fast a sheet gets eaten depends on your fish and how many of them there are, so we are not going to hand you a number of hours. Watch your own tank once and you will know.
Can a feeding ring hold duckweed and floating plants too?
Yes. The same ring works as a floating plant corral. The wall is a border on the surface, and it does not care whether it is holding food or plants.
Keepers use a ring to keep duckweed and other floating plants gathered in one part of the surface instead of spread over all of it. The same honesty applies as with food: a ring is a wall, not a lid, so plants can still travel in a tank with busy surface flow.
One thing to think about before you pick a mount. A floating ring will drift along with whatever it is holding. A magnet mount ring stays in the corner you put it in, which is usually what you want for plants.
How does a floating feeding ring stay up?
A sealed air chamber is built into the ring wall itself. The wall is a band about 8.2mm wide, and a 5mm wide pocket of air runs around inside it. The pocket is not a bolted-on collar, it is part of the wall, and its ceiling is tented so the printer can build it with no supports.
Here is the part most sellers skip. We can prove the air pocket is fully enclosed in the model, and we did, by slicing the shape 124 times across the chamber and checking every slice. That is a statement about the model. It is not a promise about a printed part. On an FDM printer, whether a part weeps comes down to how the layers bond when it prints, and no shape can settle that.
So we are not selling the floating rings yet. The plan is simple and physical: print one, hold it under water, and watch for bubbles. Until that is done, the rings we sell are the magnet mount version, and the Nori clips come as magnet or rim clip.
Frequently asked questions
Do fish feeding rings work?+
A feeding ring is a wall around a patch of the surface, so it gives floating food a border while the water is calm. It is not a seal. Strong surface flow or fish pushing at the wall can still move food out, so try the ring in a quieter spot first and watch one feeding.
What is a floating feeding ring for an aquarium?+
It is a feeding ring that rides on the surface on its own instead of being held by a magnet or a clip. Ours does that with a sealed air chamber built into the ring wall. You can lift it out and move it wherever you want to feed.
What can I use as a fish feeding ring?+
Plenty of people make one at home from airline tubing joined into a loop, or from the neck of a plastic bottle. That works, and we are not going to pretend it does not. A printed ring gives you a set opening size, a flat wall, and a mount that holds it in one place.
How do you use a Nori clip?+
Fold the dried sheet a little narrower than the plate, push one end down into the first slot, then bring it back up through the second slot. Mount the plate with a magnet on the dry side of the glass, or clip it over the tank rim and snug the thumb screw by hand.
How long should you leave Nori in the tank?+
Take it out when your fish stop picking at it. Leftover algae is just food sitting in your water. Check the clip the same day you load it, pull what is left, and rinse the plate before the next feeding.
Can you use a feeding ring to hold duckweed or floating plants?+
Yes. A ring corrals floating plants the same way it corrals food, by putting a wall around one patch of the surface. A magnet mount ring is usually the better pick for plants, because a floating ring drifts along with whatever it is holding.
A note on safety
We print every part in PETG. It is the material aquarium keepers have used submerged for years. We cannot promise how any part performs in your tank. You know your tank and your animals best, so the call is always yours. Rinse each part in clean water before you add it to your tank.
Shop feeding rings and Nori clips
Magnet mount rings with a 60mm, 80mm, or 100mm opening, plus Nori clips in a magnet or rim clip version. Magnets and the thumb screw are not included. Made in the USA. Printed in the USA when you order.
See all feeding rings and Nori clips →