Dreaded Yellow Fuzz growing on petrified coral reef rock

[TexasDefender]

I bought the following from petsolutions dot com to add to my 50# of live sand in order to get my new 29 gallon salt tank up and cycling: "Reef Rock: A spectacular addition to fish or reef tanks. Actual petrified coral! Reef Rock is ideal for use as a base rock on which to attach invertebrates such as anemones, soft and hard corals, etc. Clean and pure, not bleached or chemically treated. 50 lb. box." About 2 weeks ago I positioned the coral rocks on my 2-inch-thick, week-old live sand and started waiting out the sacred month before buying fish to allow the tank to cycle etc. Well, my coral rocks were pure white until a couple days ago, when something started growing. Unless there is a yellow fuzzy coral growing out of the old holes in my supposedly dead (?) coral rocks, I apparently have "tank rot." Would someone here who knows much more than I do look at the two attached photos (showing white petrified coral with yellow fuzz growing on it). Should I be glad anything is growing? Or should I go on a crusafe to kill the yellow fuzz? I don't have chemical test kits yet, but my tank is at 79 degrees Fahrenheit, and 1.023 salinity.

To anyone who takes the time to look and respond, thank you very, very much. This is my first venture into saltwater and I don't want to have a toxic tank.

[subsailor]

Looks like diatoms to me, should be part of the cycle. Do you have any Live Rock in there as well?

[TexasDefender]

Looks like diatoms to me, should be part of the cycle. Do you have any Live Rock in there as well?

I have no other rock (except for a golf-ball sized piece of live rock rubble that came as a freebie with the live sand). I was told at the time that if my sand was "live," my rock didn't have to be. What's the difference? Different critters?

[jroescher]

Where did the live sand come from? If it's from a bag, it isn't really live sand. If it came from someone else's tank, your probably good to go. At 2 weeks, it's only getting started.

[SoLiD]

When light (natural or artificial) hits that white rock it will start to grow algae. There is no way around it. It looks like diatom algae to me also. Don't worry, it is all normal.

-David

[Mr Cob]

Diatom algae. Not to worry. Next you will see other colors of algae and stringy worms.

If your sand was prepackaged in store bought bags claiming "live sand" I would post a thread to see if you could get a back of actual live sand from your fellow reefers on MAAST.

I give you a small bag of some to help seed your tank. I have a 2 year old sand bed that has all kinds of things in it.

PM me if you want some. It will just be a small bag but it will help add some live stuff to your current sand.

[TexasDefender]

I will PM Mr Cob. Thanks!

[J_G]

yup...thats normal growth for new rock...welcome to the jungle..i mean ocean!

[MKCindy]

Do you have any power heads in there? It helps, but all things must run their course. I can't remember if green algae or red comes next, but pink/purple Coraline trumps all... eventually. My understanding is one type of diatoms grows until it runs out of a food source in the water, then another kind of algae begins eating it until it runs out of food. If you see a lot of bubbles forming under the carpet of diatoms, reduce light time. After your perimeters settle down, you will still have mini-cycles for months. Patients, slow and steady wins the race. (and saves a lot of money too)