I wouldn't think it harmful, either.

Al

I seem to remember a class project with celery and red food color when i was a kid. As the celery sat in water and food coloring it sucked up the food coloring and turned red. I wonder if red plants is something you would have to worry about. Would it stain your pots, soil or what ever your pots are sitting on?

I think it may turn parts of your plants red if you use enough of it. Are these decorative or edible plants?

Fyi, I tried this out and it worked awesome. I added just a little red food coloring to the foilage pro/water solution. It was enough so that I could tell if the syphon was properly working (clear white water coming out, wasn't working ... slightly pink water coming out, syphon was working).

Interestingly, the Dramm hand revolver would not work with the Syphon, for whatever reason it wouldn't pull the solution out.

The Dramm AL 170 water breaker worked great (I use it with a wand). http://www.dramm.com/html/main.isx?sub=10

Bill

Ania - my garden is almost all decorative. I'll keep an eye out though to see if any of the plants starting turning "red" :)

thinking of when you put a white flower into colored water, how it turns that color but I'm sure you won't have that problem if you are just using a little bit. If you are using a lot of it, I think it's a valid concern.