I recently purchased an Eheim Skim 350 and found myself in the same spot as many others, needing to shrimp and fish-proof the skimmer opening.
I have tried out various materials and figured I would list them here for the benefit of others 🙂
Modification number 1 was a covering of this very fine mesh, repurposed from a bird cage seed catcher from ebay. The mesh is completely baby shrimp proof but almost completely inhibited the functioning of the skimmer.
(Skimmer part +final modification for scale in photos).

Modification number 2 was this mosquito netting made to cover your head. I bought mine from a local store but found a very similar looking product on ebay. It should be possible to get the material in black as well. This mesh should keep out all but the absolutely smallest baby shrimp, but you lose some effectiveness of the skimmer. The modified skimmer head will need to be cleaned often.

Modification number 3 is a stiff mesh made of plastic. If the ebay link expires some time in the future, it can be found by searching for "Plastic drainage mesh". I cut the mesh to fit between the slots and attached it with synthetic sewing thread under the lip of the head to lock it down. This will only keep out shrimp down to sub-adult size, but I found in my tank that the smallest baby shrimp tend to stay in the plants and not swim about that much so I found it to be an acceptable tradeoff. With this mesh the skimmer function is barely disturbed, but it needs to be kept an eye on, because a few plant leaves will clog it up and the skimmer will suck down the head and stop skimming.

Modification number 4 is stainless steel mesh cannibalized from a shrimp intake guard. It goes inside the slots like in the second picture here that I have shamelessly stolen from the internet. This mesh is much too fine and the water just bypasses the mesh and flows over the top. You could probably experiment with different densities of mesh to find one where the water will go mostly unimpeded through the holes while keeping critters out. I have not tested this one for long as there is a chance fish will go over the top and end up in the skimmer. That was not a risk I was willing to take.

Modification number 5 is my favorite so far. The mesh is from a black loofah. The mesh is stretchy and easy to wrap around things, but a bit delicate so take care when cleaning it and dont pull too hard. It also happens to be my favorite material for use in securing pump outlets from athletic and suicidal fish. Its attached with a cable tie. The modification steals a little bit of movement room from the skimmer. The water goes through this mesh very easily and since the surface is larger it can take more than two plant leaves before clogging. Should keep out shrimp down to sub-adult size. It impedes skimmer function only slightly more than number 3, but still allows for effective skimming.

Hope this post helps if others need to modify their skimmers, or if they are like me and love a bit of DIY they have some ideas for materials to hoard
I have tried out various materials and figured I would list them here for the benefit of others 🙂
Modification number 1 was a covering of this very fine mesh, repurposed from a bird cage seed catcher from ebay. The mesh is completely baby shrimp proof but almost completely inhibited the functioning of the skimmer.
(Skimmer part +final modification for scale in photos).

Modification number 2 was this mosquito netting made to cover your head. I bought mine from a local store but found a very similar looking product on ebay. It should be possible to get the material in black as well. This mesh should keep out all but the absolutely smallest baby shrimp, but you lose some effectiveness of the skimmer. The modified skimmer head will need to be cleaned often.

Modification number 3 is a stiff mesh made of plastic. If the ebay link expires some time in the future, it can be found by searching for "Plastic drainage mesh". I cut the mesh to fit between the slots and attached it with synthetic sewing thread under the lip of the head to lock it down. This will only keep out shrimp down to sub-adult size, but I found in my tank that the smallest baby shrimp tend to stay in the plants and not swim about that much so I found it to be an acceptable tradeoff. With this mesh the skimmer function is barely disturbed, but it needs to be kept an eye on, because a few plant leaves will clog it up and the skimmer will suck down the head and stop skimming.


Modification number 4 is stainless steel mesh cannibalized from a shrimp intake guard. It goes inside the slots like in the second picture here that I have shamelessly stolen from the internet. This mesh is much too fine and the water just bypasses the mesh and flows over the top. You could probably experiment with different densities of mesh to find one where the water will go mostly unimpeded through the holes while keeping critters out. I have not tested this one for long as there is a chance fish will go over the top and end up in the skimmer. That was not a risk I was willing to take.


Modification number 5 is my favorite so far. The mesh is from a black loofah. The mesh is stretchy and easy to wrap around things, but a bit delicate so take care when cleaning it and dont pull too hard. It also happens to be my favorite material for use in securing pump outlets from athletic and suicidal fish. Its attached with a cable tie. The modification steals a little bit of movement room from the skimmer. The water goes through this mesh very easily and since the surface is larger it can take more than two plant leaves before clogging. Should keep out shrimp down to sub-adult size. It impedes skimmer function only slightly more than number 3, but still allows for effective skimming.


Hope this post helps if others need to modify their skimmers, or if they are like me and love a bit of DIY they have some ideas for materials to hoard

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