Can someone ID this please?

[ot7]

im cleaning out my tanks filter and these things are inside of it. they kind of look like clams except they only have one side shell and the other side their insides.

 

[Rutrag]

Limpits

 

[sleeper]

+1

 

[dirtyd61]

For sure a limpit as others have said. Some are good and eat algae, some are bad and will possibly eat corals.

Keyhole limpits are the bad ones.

 

[Dizzirn]

How do you tell them apart?

@Humblefish

 

[reef lover]

Keyholes have a hole on the point of their shell...that kind is fine

 

[dirtyd61]

They aren't a big deal if you don't have sps

 

[Humblefish]

As mentioned above, you generally only have to worry about Keyhole Limpets (Megathura crenulata) with SPS corals. Photo below.

As @reef lover said, a Keyhole will always have a hole on top of it's shell regardless of colour.

 

[Dizzirn95]

Thank you @Humblefish and @reef lover