How bad is it to have hitchhikers? FYI...

Sk8r

Staff member
RC Mod
In general, a lot of things ride in on live rock, and in general, you want almost all of them. I set up with live rock and counted 52 separate species that came in with it. Worms, snails, copepods, amphipods, sponges, even bits of coral, algaes, etc...

The bad: pretty well limited to 1) fireworms, not to be confused with good bristleworms. They don't look alike. Look up hermodice carunculata on the internet. That's one bad guy.
2) eunice worms. This guy could live fine in your sump, but not in your tank. Look up eunicid worm. The tentacles are a dead giveaway.
3) crabs of most sorts. Little microhermits are good: hairy crabs are not. Nor are crabs in general that have distinctive large claws. Also do not be conned into buying a sally lightfoot or arrow crab. Interesting in your sump, but not for a reef.
4) shrimp: in general, things that go click and bang! in your tank late at night are predators, either pistol shrimp or mantis. They're fishkillers. I'm not personally keen on shrimp-goby pairs, either, after my tiger shrimp grew up and killed his goby partner plus several other fish before I took my tank apart to extract the fellow.
5) flatworms---some kinds are a problem, some less so. Many have a V taken out of the tail. THey range from tiny to monster. They're mostly a problem because they get so prolific so fast.
6) aiptasia or majano anemones --- never grow above an inch in size, though they are stretchy. They're brown, don't get color. Peppermint shrimp, if they take to eating them while the shrimp are juveniles, will assure you never have any problem with them. The trick to getting shrimp to eat them is buying about five juvie shrimp---out of the five, usually one will take to them. I've had rare setups where my five were ALL duds. But the next five would produce ravenous aiptasia-eaters. I like the little nems in the sump fuge: they're not bad citizens down there. In the tank, they can sting corals and get pushy, but honestly, I've raised corals for many years and never found them much real problem. If you overfeed your tank, you could see them multiply, but if you have a big bloom of ANY creature, figure you MAY be overfeeding your tank. Cut back, for starters.
Those are the chief problems, save one: ROOTED algaes. If it has roots and grows in the rock, and especially if it's caulerpa, get that rock out, and if it's the whole batch, that's a serious problem in any tank under 100 gallons: why? Because the only fish that can eat caulerpa (the onespot rabbit) is equipped with a poison spike and can turn killer of other fishes in a tank under 100 gallons. The other fish that will tackle algaes is the tang---and they also are a 100 gallon fish.
I advise against letting caulerpa exist in your sump, because it reproduces by spores and by fragments. It's far worse than hair or bubble algae, and is illegal in California for good reason.

Hope that's some help.
 
Last edited:

syngraves

New member
ive had my tank up for about a year and have been hearing a scratching/ clicking from the tank at night. havent lost any fish or snails (except for one green chromis) so i havent really worried about the noise.

think its worth the time to set up a trap at night to see if it is a pistol or mantis shrimp?

the sound is almost like if you scrapped a knife across the live rock.
 

lespaul339

Reefer
And that's why I started my last build using dry rock. I didn't want to deal with hitchhikers in this tank. Nothing is in my tank unless I introduce it. I used live rock in my old tank and while it's cool to see all the critters that come with it, it also sucks when you have to deal with something you didn't want to in your tank and try to figure out how to get rid of it. No more Aiptasia for me.
 

Sk8r

Staff member
RC Mod
I usually have a lot of aiptasia in my fuge, where they're good citizens. If any should survive the pump and make it to my DT, the pep shrimp will take care of them. I rarely see him, but he's still in there, and aiptasia aren't. If you have shrimp-eating fish, that's, however, a problem.
 

FraggledRock

New member
ive had my tank up for about a year and have been hearing a scratching/ clicking from the tank at night. havent lost any fish or snails (except for one green chromis) so i havent really worried about the noise.

think its worth the time to set up a trap at night to see if it is a pistol or mantis shrimp?

the sound is almost like if you scrapped a knife across the live rock.

that can simply be a snail up against the glass or a hermit crab doing the same. hermits can move sand and crushed substrate and are relentless at trying to climb glass at night =P
 

Sk8r

Staff member
RC Mod
A pistol shrimp sounds like a small firecracker going off (or your glass cracking) when it really sounds off, though sometimes you will have a series of little clicks. Mantis shrimps are much the same. Fascinating creatures. But not so nice to their tankmates.
 

syngraves

New member
ok cool. ive been thinking it was just a snail getting itself wedged between the rock and glass. theres acouple of snails in my tank that are bull dozers. if it isnt glued down or too heavy, they move it... had a head of frogspawn on a plug down in my sand bed acclimating to flow and light. left it overnight and next morning it was knocked behind my rock work on the opposite side of the tank
 
Top