Hydroids?

This morning, my fiance texted me a photo of some new apparent life that we have growing inside our tank on three of the four walls. Photo below. He did some quick Googling and tells me they appear to be hydroids. I've been at work and unable to do a ton of research, but I see via a quick search that hydroids are "predators related to jellyfish," and it seems some can be good and some can be bad. I'll do more research later, but I would love to hear what you all have to say. Do they appear to be hydroids? Are they anything to worry about?

(The tank is still going through its first cycle—about a month in, haven't yet detected an ammonia spike, ammonia and nitrite levels are at 0 and nitrate is at about 15-20 ppm. We had our first feather dusters appear out of our live rock a couple of weeks ago, and we've had one sighting of what we think might have been a fireworm, though it just peeked its head out briefly, a couple of weeks ago, and we haven't seen it since. Other than that, we have no [known] life in there. We have been feeding the tank fish food for the last week or two; last night, I removed the filter socks and let loose all the fish food that had been building up in there, in hopes that freed food will decay and spike ammonia more quickly.)

We're also seeing little copepods on the glass! Starting to seem like some real activity is actually happening in this tank! :)

If we were to add a deli shrimp to kick-start the ammonia spike, how long after adding it should we expect to see an increase in ammonia? To this point, we've still never had an ammonia reading above the very lowest levels, which I like to think means we already have a good healthy load of nitrifying bacteria. I want to plop the shrimp in there to watch ammonia spike and then see if it quickly returns to 0, so I have a good read on whether we really do have that bacterial colony nicely established. At which point we'd start to add some CUC despite having not yet seen a diatom outbreak. Am I on the right page?


Edited by dougandtito - January 06 2015 at 9:57pm

"The shrimp" meaning deli shrimp or live shrimp to start the CUC?

Edited by dougandtito - January 07 2015 at 11:54am

Oh we have been! That's a great shot, though. :)

Super awesome stuff! Glad you're enjoying your new tank. The microscopic life is one of the most interesting parts of reefkeeping in my opinion. Get a microscope, you won't regret it :D

deli or brine or mysis. doesn't matter which.

Edited by hydro phoenix - January 08 2015 at 6:38pm