Anyone who has ever sprayed liquid herbicide (or any chemical) over a large area of ground will appreciate the problem. It is tough to remember exactly where you sprayed and didn't spray. You end up with either large gaps, or areas sprayed multiple times, or both. This product helps out quite a bit.

=== The Good Stuff ===

* Once you get the hang of seeing it, the blue is distinguishable even on green grass. It helps a lot if there are patches of bare ground, or some dandelions or other flowering weeds, but you can see the blue even on grass. It helped me a lot wear polarizing sunglasses.

* I mixed it per the label instructions. I suppose a little extra would have helped things along- maybe next time.

* Cleanup wasn't as bad as I feared. The instructions mention bleach, but I just ran a little extra plain water through my backpack sprayer, and the blue dye cleaned up. There might be just a slight blue tint to the clear tubing lines on the sprayer, but it gives the thing a little class.

=== The Not So Good Stuff ===

* This stuff should really ship with a box of surgical gloves. The instructions say the dye will wash off skin with repeated washings, but I suspect it really means that once the skin wears away, the dye goes with it. And if you get it under your fingernails....well, good luck.

* I was not a fan of the bottle. It didn't pour real cleanly, meaning the stuff dribbles down the side of the bottle. Makes for a real mess. A squeeze bottle, or some sort of pump would have been appreciated, even if it added a few cents to the cost.

=== Summary ===

In the end, the product did what it claimed. There are a few things that could have been better, but it solved a problem, and probably paid for itself in less double spraying. I would have much preferred a brighter color (yellow or orange), but I suspect the blue dye was the easiest to make work. If you are colorblind to blues and greens, don't even bother.

Works great! Shows me where I've hit and where I've missed. I end up using a lot less herbicide because I don't have to guess and just spray again on the same old spot since I wasn't sure if I had hit it before or not. Also shows when what I'm spraying is beading up or not due to the wrong amount of surfactant. Doesn't hang around too long on concrete. The one big issue I have with it is that the manufacturer should provide a better way to dispense it. It gets EVERYWHERE and I mean EVERYWHERE. Floors, walls, sink, clothes, the ceiling, your brother's car in storage in Wisconsin, EVERYWHERE. I suppose other liquids do the same but aren't as noticeable. So perhaps it's a good thing just to let me know that even when I'm trying to be careful with chemicals, they're getting onto surfaces that I think they're not. But I would still prefer a better way to dispense it.

This does exactly what it is supposed to do. I used the recommended dosage amount and could clearly identify where I had and had not sprayed the herbicide. There were no long term effect or damage whatsoever and the blue tint quickly dissipated in a couple of days, and virtually immediately when we had a thundershower roll through. I do recommend this product for those people who are spraying herbicide and want to easily identify where they have already sprayed and where they have not. Again, this product works exactly as advertised.

Due to location, I have to hand spray weed killer on hundreds of thistles. It's like walking through a jungle...the vivid blue color helps discern plants already sprayed. Second day..blue not so visible and I find I am spraying plants I already hit. I am going to try a surfactant to see if that helps retain the color longer.

Works really great, now can see what has been sprayed, saving going over things extra times. Easy to see, and fades away after about 2 days even without rain. I use about 1.5 ounces for 3 gallons of spray, and its plenty visible, might even be able to cut that down some and still work.