Newbie needs help with brown Algae

[chibbycheezcake]

Hi guys! I discovered yesterday, that brown spots are all over my white sand. Is this what they call "diatoms"? How do I get rid of this. I also took some water from my tank this morning to take to the saltwater petshop in the late afternoon. Will this water still be okay to test or does it have to be fresh at the time of testing?
Thanks for all your advice on my last post. Since Im newe to this forum, when i start a thread and have a new question, can I continue with the old thread or do I have to start a new one.

Chibby

 

[mr. limpid]

1. diatom will go away
2. Yes for most test, except oxgen test, best to invest in your own test kits.
3. start new thread you'll get responces from an unanswered thread.