What to do with these rocks

[JTA15]

Got these rocks from a local fish store are probably super old. Is this cyano or Coraline? Also are Bristol worms a big deal. I am just starting my first tank so I don’t know anything. Want to know whether or not to return these rocks.

 

[Fish Fan]

I think those look like very good, mature rocks

To me, that looks like coralline algae.

Bristle worms are generally considered a beneficial clean up crew critter, however they can grow in numbers to "plague proportions" under the right circumstances, and some species get kind of big, which can creep people out. I would leave them alone until one of these two situations are reached, at which time you can trap them or get something like an arrow crab that will eat them.

I hope that helps!

 

[JTA15]

I think those look like very good, mature rocks

To me, that looks like coralline algae to me. Bristle worms are a beneficial clean up crew critter, however they can grow in numbers to "plague proportions" under the right circumstances, and some species get kind of big, which can creep people out. I would leave them alone until one of these two situations are reached, at which time you can trap them or get something like an arrow crab that will eat them.

I hope that helps!

Thanks. I put these rocks in to start my initial cycle. Will the cycle kill off the algae or the worms and if this is Coraline algae does it need a light or a certain calcium level to sustain or can I hold off until my tank is more developed?

 

[Fish Fan]

Thanks. I put these rocks in to start my initial cycle. Will the cycle kill off the algae or the worms and if this is Coraline algae does it need a light or a certain calcium level to sustain or can I hold off until my tank is more developed?

If you're starting your tank with real live rock like what you have pictured, there is no need to cycle, the rocks are already cycled

Don't add any ammonia or anything like that, just let the tank run for a day or so, then double check that there's not some spike in a ammonia from anything dying off just from the move, and if not you could start to slowly add some hardly livestock.

Cycling a tank is more for when you use all dry rocks and sand to get started.

Post back with any further questions and I'm sure someone will be able to help