Growth On 10+ Year Old Live Rock

JustForFun · Aug 13, 2020

Hello! Just looking for an ID. If I'm in the wrong thread then I apologize in advance.

Anyway, I was recently asked to take on the maintenance of a 125 FOWLR that is well established. Most of the rock in the tank has been there for 10 years or more. One of the first things I noticed when I saw the tank were these spikes growing on the LR. They were also on the inside of the overflow and on some of the powerheads. My guess is some sort of calcium buildup, but I'm not entirely sure. The owner asked me what it was so I took some pictures and a video and told him I'd get back with a better answer than "not too sure". So the pictures clearly shows what I'm guessing is detritus and the spikes growing from the rock. Any answers will be much appreciated .

ReeferWarrant · Aug 13, 2020

Those might be vermitid snails, which would be a nightmare. Do you see mucous strings coming out of the tubes when you feed? My assumption is either vermitid or some sort of tube worms.

brandon429 · Aug 13, 2020

agreed they're that, and inevitable

if we trade wet reef supplies some green micro algae spores are riding, some cyano cells, vermitids, and filter baceteria nearly always. I would never ever bet that a relocation of hardscape items would lack all those and eighty more species

Sump Crab · Aug 13, 2020

less feeding will reduce their numbers.

JustForFun · Aug 13, 2020

ReeferWarrant said:
Those might be vermitid snails, which would be a nightmare. Do you see mucous strings coming out of the tubes when you feed? My assumption is either vermitid or some sort of tube worms.

Can you elaborate on the nightmare part? . Not too sure about mucous. I'm not usually around during feeding time. I'll ask the owner to keep an eye out.

vetteguy53081 · Aug 13, 2020

Youre seeing what looks like sponge but are Foramnifera , the branching white type are usually mistaken for a sponge, but if you look closely you can see what looks like thin hairs at the ends of the stalks, these are the Rhizpodia which collect food particles . Harmless but unsightly.
The tubes appear to be colonial hydroids or tube worms. Assure little dusters are coming out of it. If not, may be macroalgae.
If so, hydroids are a diverse group of creatures and a few are fast reproducing, having wicked stings towards fish and coral. Many of them are slower growing, and delicate, and seeing them bunched together could be a sign for caution, as to how quickly are they growing.
If vermetid, 2 little hairs will come out of them seeking food, but thinking tube worms

ReeferWarrant · Aug 13, 2020

@JustForFun, they spit out mucous to catch floating particles. If this wasn't a FOWLR, and you had corals youd be hating life. The mucous irritates corals and they dont extend their polyps, which will kill the coral after too long. It could be sponges as well, I'm not certain about the vermitid aspect. If the base of the stocks spirals like a snail shell though it is them.