Sponge or "mold" on live rock?

[Jcg]

Hi All,

We have a 96lt tank...we are new to this hobby so apologies in advance if anything doesn't makes sense!

It's being a week with the Tank, no livestock in it yet...just the Live rocks (pictures below)...









This morning they appear with a white "thing" around...looks like mold but I've been reading and it says it can be a sponge?

The question is: Is this normal? should we do something different?

As well, we are using tap water + red sea salt...is this ok?

Thanks

[Sniperhank]

It isn't a sponge. It is most likely globs of bacteria forming. I'm assuming that you are cycling your tank currently? This wouldn't be too outrageous of a sight if that is the case. Just make sure you have powerheads in the system so the flow in there breaks all that gunk up. If it bothers you too much, hit it with an old tooth brush. It should be harmless, but I've only witnessed it once out of all the cycles I've done.

[Jcg]

Thanks Sniperhank! Yes I am cycling the tank currently....is just taking a while to reduce the ammonia levels of the tank...I'll put in practice your advise. Thanks again

[Sniperhank]

No problem. Just remember that this is more of a hobby of patience than fish. Just make sure you continue to present an ammonia source to the tank. Once you get 2 ppm ammonia converted the entire way to nitrates in a 24 hour period you are cycled and ready for water changes.