LFS live rock

[Bantha]

I'm planning my first reef tank, but still deciding on whether to go with only dry rock or use wet live rock. I see my LFS offers live rock. They seem quite professional but, I don't want to risk bad hitchhikers for low quality live rock.
What do I need to look out for? Obviously they should be purple from coralline algae, but I suppose they should have a light above the tank as well to keep the coralline algae alive? How do I spot quality live rock?

 

[salt2salt]

If you like it buy it. Most lfs are very cautious about what they put in their water.

 

[Deep]

I'm planning my first reef tank, but still deciding on whether to go with only dry rock or use wet live rock. I see my LFS offers live rock. They seem quite professional but, I don't want to risk bad hitchhikers for low quality live rock.
What do I need to look out for? Obviously they should be purple from coralline algae, but I suppose they should have a light above the tank as well to keep the coralline algae alive? How do I spot quality live rock?

Make sure the tank has cycled first before putting the live rock, so that way there is lesser die-off.

 

[Tired]

You should see plenty of colors. Not just solid purple, that can be painted. Good rock would likely have some bits of orange or other shades, and multiple shades of purple. Look closely at the rock, see if you can spot seaweed or coral parts. Tubeworms and sponges are more common and are good signs. Clamshells, with live or dead contents, are good as well. Those would all indicate the rock is out of the ocean, not just from a vat. You shouldn't smell any stink if the rock has been aged. If it stinks, you'll need to let it age.

Live rock pests are mostly not a big deal. Aiptasia is the biggest (common) one. Just look for them while the rock is in the water, you should be able to spot them if any are present. Crabs, mantis shrimp, pistols, and so on are relatively uncommon, relatively minor pests. The best thing to do about those is just to observe the tank at night after you've bought your rock, and set bottle traps to catch anything out. You can't really avoid them for good, but they aren't a major concern in most cases anyway.

Live rock IS your cycled tank. It should be the only ammonia source in your tank. If the LFS has already aged the rock (leaving it in water until it's finished with any rotting bits), you should see no ammonia at all. Putting mature, aged live rock into a tank makes that tank instantly cycled, no need to add anything else.

 

[Nick063]

Look for beneficial hitchhikers like pods, sponges make sure it’s kept in a tank with flow...essentially it will help speed the results of your cycle

 

[AquaBiomics]

Look for highly porous material that is really a piece of old coral skeleton. Some of the mined or manmade stuff is so non-porous its not very useful no matter how long its been in the water.

Color (pink or purple from coralline algae) is a good sign but can be misleading in both directions - some manmade rocks are painted purple, and high quality live rock that was stuck in the dark on the bottom of the tank can be almost bone white.

 

[brmreefer]

In my opinion, a good indicator of potentially good live rock being available at the location is to take a good look at the LFS' display tanks. If everything looks clean and orderly, then that shows they take some pride in their store and more apt to taking care of the customers versus make a quick dollar. Taking care of customers usually leads to repeat visits, purchases, conversations, and loyalty.

Note: This does not guarantee the absence of bad hitchhikers, but at least the LFS may take caution with where they source the rock.

Just my 2 cents.