Are Sharpie Markers Reef Safe?

For my son's science fair we are going to frag a green slimer and put all the frags at different locations in the tank with different light levels and measure the differences in growth rates. We need some way to number the ceramic frag plugs. Scratching numbers in them doesn't work too well. I was wondering if sharpie marker after it dries is reef safe.

 

u could use paint

 

Can you place them in the tank and write on the outside of the tank with dry erase marker instead? I would place them and then mark them on the glass. I have seen that at the stores a bunch.

 

Anyway to possibly "notch" the plugs? I honestly don't know if Sharpie marker's are reef safe, but I would be hesitant to use them.

 

Don't know if they are reef safe or not but that sounds like a good science fair project to work on.

 

Yeah. I'm not taking any chances. I'm scratching Roman Numerals in them. Much easier to scratch roman numerals instead of Arabic numerals. Thanks for your replies. Karma to you all.

 

spray paint the frag plugs first different colors

 

Kudos for science!

And karma for doing it with a kid!

 

many use them to mark plug markers with no harm. Use the lab grade ones, the are far better then the run of the mill ones.