Mysterious White Milky Bubble On My Sand? What Is This?!

[softmushroom]

Does anyone have a clue on what this is?! It started growing around my sand and decoration. Tried searching on Google, but no luck! Kinda worried..

I have no fish in my tank. I am currently cycling

 

[willikris]

I am currently cycling as well and have similar looking "stuff" on my air tubing....still waiting for an answer myself!

 

[libimagana]

I think is some type of algae.

 

[wildroseofky]

I believe it is a bacterial growth. I just had this happen in my 5 gallon and it took over the tank. Killed my shrimp and snails. It is caused by an over abundance of organic matter like fish food. vacuum clean the tank and do a massive water change. That stuff will grow out of control. Water changes will not hurt your cycle.