what makes the sounds?

[AquaRa]

i've heard knocking sounds coming out from my tank, what made them. i do not have any shrimps and snails

[andysho]

taht should be those terrible snapping shrimps

that hiding in your deep sand bed or so

i used to have some of that too

maybe can check if there are any shifting of sandbed position in your tank

[nqh71]

Should be pistol shrimps... had the same thing happen to me long time ago...

[[d]3v|L]

Pistol Shrimps. I hate them!!

[andysho]

they had killed some of my small fishes

sob sob

somtimes appear to have only 1

but turn only to be tones of them hiding in the deep sand bed

what a curse in a tank to have this shrimps............

[AquaRa]

the only thing which is moving the sand is my clam

[alanyeo]

Pistol or snappy shrimps, whatever they are...nasty, and if got female in there worst....breed fast. Can be found between rocks and sand, even Pasir Ris beach.

To get rid of it - After lights off, securely tie a slice of prawn in a fishnet and wait. It will attempt to grab it from net. You got to work fast! Happy Shrimping!

[andysho]

sentosa beach also got a lot ,some look colourful somemore hahahha

your that after lights off......................net sounds like what those kong fu fighters in drama do sia.... when they fishing they also do that muahhahah

[Dispar_Anthias]

Pistol or snappy shrimps, whatever they are...nasty, and if got female in there worst....breed fast. Can be found between rocks and sand, even Pasir Ris beach.

To get rid of it - After lights off, securely tie a slice of prawn in a fishnet and wait. It will attempt to grab it from net. You got to work fast! Happy Shrimping!

Small pistol are in fact reef safe....... Some even bond relationship with other goby

[ai[k²]wan]

y no one mention mantis shrimp

[georgeswb]

Cld be mantis shrimp...but those small green ones are quite harmless..If u can..remove them from your system totally.

[SpiderOne]

the only thing which is moving the sand is my clam

can elaborate more?

[Tanzy]

If it is snapping or clicking then it will be the shrimps. If it is a knocking then it will be the snail shells.