ID Critters

[Nick Rose]

Need help identifying these critters in my tank. The video does not show the true color. The first two photos are more of a white color. The last video it was hard to get good lighting. They are backlit. In the last video the critters look like slugs/worms and one of the bugs has a "V" like tail.

 

[tankstudy]

1st video = hydroid
2nd video = looks like snails similar to Zig Zag Periwinkles, or even a smaller species
3rd video = small copepods and flat worms

 

[Nick Rose]

Are flat worms dangerous. This tank is a backup/emergency tank. It has some corals in it but no fish.

 

[tankstudy]

Not all flatworms are bad but some indeed are.