Sea marker dye

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The Sea marker is red and the flourecein is green.

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Are you sure? Looks fairly green!
pl26898.jpg
 
Sorry I just replied to the last post. It was in the quote though! Perhaps I was refering to that /forums/images/graemlins/wink.gif

I did just wonder if the sachets contained a solution. The solid may be a bit slow to disslove but but it is a pretty vivid fluorescent green once dissolved. Everybody must have seen it at some time or other I would have thought (and I thought every school boy had the correct spelling drummed into them by their chemistry teachers). Normally when I have made solutions of it I have added a little caustic soda to make the solution alkaline as it does not fluoresce in the acid form but seawater is plenty alkaline enough.

£85 per 500g from a lab chemical suppliers but the Screwfix link does not say how much you get for £6. 500g would colour half the channel I should think
 
Plumbworld do it in 4 & 8oz packs for a bit less. THe ideal way to use it is to load into a fabric sausage so that when immersed the dye releases slowly to produce a long plume. You need very little to colour a whole lot of water.
 
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The stuff I've come accross was red.

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Any idea what it was. A Google search just kept on turnig up the same yellow green dye.

You actually saw it in the water I suppose because fluorescein is a reddish brown powder and concentrated solutions (of its sodium salt) are also reddish in colour, the yellow green fluorescence becoming more noticeable when diluted
 
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The stuff I've come accross was red.

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Any idea what it was. A Google search just kept on turnig up the same yellow green dye.

You actually saw it in the water I suppose because fluorescein is a reddish brown powder and concentrated solutions (of its sodium salt) are also reddish in colour, the yellow green fluorescence becoming more noticeable when diluted

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The Plumbworld (thanks scuby) link here lists fluorescein along with red, blue, green and yellow dyes.

No idea what they contain....
 
It seems that the other colours used for drain tracing are just food dyes. Fluorescein is visible in very low concentrations due to its fluorescence in day light. I not so sure that food dyes will be so visible although some are pretty intense I suppose. They may well be more visible in atifical light though when there is no UV to make fluorescein show up.
 
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Sorry I just replied to the last post. It was in the quote though! Perhaps I was refering to that /forums/images/graemlins/wink.gif

I did just wonder if the sachets contained a solution. The solid may be a bit slow to disslove but but it is a pretty vivid fluorescent green once dissolved. Everybody must have seen it at some time or other I would have thought (and I thought every school boy had the correct spelling drummed into them by their chemistry teachers). Normally when I have made solutions of it I have added a little caustic soda to make the solution alkaline as it does not fluoresce in the acid form but seawater is plenty alkaline enough.

£85 per 500g from a lab chemical suppliers but the Screwfix link does not say how much you get for £6. 500g would colour half the channel I should think

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Just got the reply from Screwfix.

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Thank you for your recent E-mail.

This item comes in a small container which according to the image on the website contains 100g.
http://www.screwfix.com/app/sfd/sea/sear...p;x=8&y=10#

I hope that helps.
Regards,

Bob Hatcher

Product Support

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£6 for 100g seems like a bargain!
 
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