What is growing on my live rock?

I started my tank on Friday night, put in my live rock and fish within a few hours. My first set of live rocks has nothing but algae on it. My second venture at choosing a live rock, the next day, profited these little fungi looking guys. I'm wondering if its a form of coral or what I was supposed to be waiting to see on my rock. Also, if my rock has algae, should I purchase a cleaner yet or still wait.

Those are aiptasia -- pest anemones. They spread very quickly, so you should kill them ASAP. Aiptasia X is a good chemical to use on them, and is easy to use and safe for the rest of your tank. Peppermint shrimp have a 50/50 chance of eating them, if you want to get a few peppermint shrimp for your tank.

You should get a cleaner crew because you have fish. The cleaners will help take care of uneaten food and fish waste.

Has your tank been cycled??

Yeah 2 fish 1 day after putting together your tank is going to be very stressful on them. You really need to read up on how to cycle your tank so that you dont kill your pretty new clowns.

I used fully cured live rock, 50/50 live sand and regular sand, a nitrifying bacteria start, and the two clowns to speed up the process. I have tested my water every day and seen a very nice reading of ammonia, nitrite, and nitrate. I am also taking my water to be tested by my LFS. Algae has been growing over 1.5 of my 4 live rocks, and now along the entire substrate. As well as one of my live rocks turning the same purple as two of the others. I am pretty confidant in this tank.

If your reading any ammonia at all, it is causing fish stress, and could kill them.

Having fish in there will not hurry up a cycle, it will at best damage their organs so they wont live as long or worst kill them. Cycling a tank is all about growing bacteria to handle the waste, and having fish present wont make them populate your tank any faster.

Also, having algae grow is a sign of issues to come. I would not be excited about that.

Seems like a very small tank to have 2 clowns in. I have a biocube 29, it actually only holds about 20 gallons. I don't have any pics of it posted aside from my avatar. It has been up and running for a year and a half. I have a clown and 6 line for fish. My 6 line cleaned up all of my flat worms and stomatella snails. Funny watching him smash them against the glass to crack the shell. Clack clack clack whoo hoo food!!! Can't agree with little_fish more about cycling the tank and algae growth. Poor parameters = poor tank life....

Being confident should come when your ammonia, nitrite and nitrate are ZERO and you have no algae. Sounds like you need to do some more research and stop listening to your LFS who is just trying to make a buck.

yes anyone who tells you to add fish to make it cycle first is either trying to make a buck or dont know what they are talking about,live fish havent been used in about 5 years to cycle a tank,thats the old school way it used to be done,just put a raw shrimp in the tank and leave it for a while,its a hell of alot cheaper then wasting 30 bucks worth of clown fish,i am 2 weeks into my cycle on my 75 gallon and only have a few snails to stir the substrate and a few hermits to keep the rocks clean,kinda messed up the other day and had a 24 hour photo period and had a burst of cyano pop up due to my not so smart act