trying to identify macro algae and bug, reef tank.

myles4miles · Aug 10, 2025

Just seeing if anyone could ID these for me, if u know what they are. 1 weird bug I've never seen before and 2 weird seaweeds, and are either of them a big problem, for the seaweed, I try to clean as much out as I can on my weekly water changes.

YouTube short below is the bug.

Fish Fan · Aug 11, 2025

The "bug" in the video looks to me to be an amphipod, which is a small crustacean that's very beneficial and a sign of a healthy tank. related to copepods, these guys do a great job keeping the tank clean, and provide a live food for many fish.

The macro algae in the middle could be a type of Halimeda, though I can't be sure.

I have no idea what that green blob may be, but I'm sure someone will know

Good luck!

myles4miles · Aug 11, 2025

Fish Fan said:
The "bug" in the video looks to me to be an amphipod, which is a small crustacean that's very beneficial and a sign of a healthy tank. related to copepods, these guys do a great job keeping the tank clean, and provide a live food for many fish.

The macro algae in the middle could be a type of Halimeda, though I can't be sure.

I have no idea what that green blob may be, but I'm sure someone will know

Good luck!

Thank you, I think the green blob grew under the sand if that helps.

bluemon · Aug 11, 2025

Second algae is Caulerpa Racemosa (or Peltata)

which is illegal to own in the state of California.

I suggest you freeze it in a small bag and dispose of it

myles4miles · Aug 11, 2025

bluemon said:
Second algae is Caulerpa Racemosa (or Peltata)

which is illegal to own in the state of California.

I suggest you freeze it in a small bag and dispose of it

illegal to own.
I didn't buy it
Why, is it just invasive?

bluemon · Aug 11, 2025

myles4miles said:
illegal to own.
I didn't buy it
Why, is it just invasive?

yup, super invasive.

yea it's illegal to buy and sell, now to own ALL species of Caulerpa. previously, some species like Prolifera were okay to own, but now all under the Caulerpa Genus are illegal to own.

They always keep finding patches in local waters. The worst being Caulerpa Taxifolia.