Diatoms on sand

[zookey]

Two questions:

1.. Are they harmful to a puffer?

2.. How do you remove them from a sand substrate?

I have gravel currently in my tank. Every tank I have ever had will get those orange/brown diatoms at some point in the spring when the natural light plus artificial light are too strong. I normally reach into my tank and "rub" the diatoms off of the gravel in my current tanks, but this is the first spring I have had a puffer so I am wondering if they are at all harmful to a puffer. Also am planning on changing up his tank eventually. Planning on moving him up to full marine with live rock and sand. So I am wondering how to remove them from the tiny pieces of sand or don't you. Maybe you don't even get diatoms in salt water..... please forgive me, this is all still really new and I am trying.

Thanks for your help.

[Pufferpunk]

Nope, not harmful: library/water-filtration/brownalgaediatoms/

[zookey]

Thank you...