Reef Safe marker

[Playdope]

I need to make lines on something asap with some kind of reef safe marker, or anyway you guys can recommend. The lines will be underwater... so I dont want anything being released into the water.

Thanks

 

[Anonymous]

Greace pencil maybe?

I don't know how well a wax crayon would work, but it may do well too.

You could always experiment with a glass of water or a glass baking dish filled with water.

 

[Anonymous]

Sharpie markers are permanent, and I don't think they're going to leach anything into the water when they're dry.

Jim

 

[Anonymous]

Why not just mark the outside so you can "erase" them later?? - Why the need for inside? (Just curious...)

 

[Playdope]

Inside, because I am needing to mark the high and low mark on a top-off sensor switch for the LiterMeter III. This top off module shuts off the water flow to the sump when it gets too high on the probe, and the units turns back on when the water again falls bellow the low point. I'd like some lines at these 2 points, so I could keep my water level somewhere in between the two.

 

[Anonymous]

Ok... - I did about the same thing - without the auto-topoff system anyway..

 

[Fl_Seagull]

Sharpie markers are "OK" once dry. But it does hold up well to being "water soaked" when used on glass.

As a side note, sharpie markers were once "accidentally" used to touch up black anodized panel on the SpaceLab. Tens of thousands of dollars later NASA determined that sharpie markers are perfectly safe once dried for manned spacecraft. While the NASA testing did not look specifically look at chemical leaching, it did look at the pigment toxicity and the level of solvent out-gasing.