could anyone tell me what it is?
i have live rock no coral and what i think is a tube worm
its in the sand and it closes up sometimes also i have a feather duster just looked it up as i dont know what they all r yet
no its not a majamo has had one rcentley which i got rid of
i have looked all them up and does not look like my other feather duster it closes up at night and looks like a proper flower it is a deep red

The little red flower could be a feather duster which is a tube worm which lives in a thick tube in the sand and pops its feathered head out to filter feed from time to time. If its out all the time then thats not what it is because feather dusters spend more time in their tube than out of it.

Alternatively it could a form of anenome which I can't remember the name of but its a pest and comes in with live rock. This particular form can over run tanks as they reproduce by splitting, and also by sending out eggs and sperm together. If you try to remove it, do so by using gloves as they can sting, and any fish which brush up against it, including clowns, will be killed by it.

If the anemone is removed but the base is left in tact, a new one can then grow, but does so as two specimens which then split at maturity and become two seperate ones.

To kill them directly, a needle and syringe filled with concentrated salt water, or boiling water can be injected into it which kills it, or alternatively, Arrow crabs and Copperband Butterfly fish feed on them.