EPA Regulated Pond Dye

Does an EPA registered pond dye outperform non-registered pond dyes?  Let’s look at the comparisons between each and determine the key differences between them.

First of all, products that require an EPA registration are products that have a “kill claim.”  This means that the label claims that the product will actively kill targeted weeds or algae.

EPA registered pond dyes make such a claim.  They claim that the dye takes an active role in killing submerged weeds and algae.  This claim legally requires an EPA registration.

Now, the question is, do all pond dyes actively kill submerged weeds and algae, and if they do, shouldn’t all pond dyes be registered by the EPA?

The truth of the matter is that no pond dye directly kills anything.  Pond dyes are added to reduce sunlight penetration into the water column and that is exactly what it does.  It can also flocculate small particles out of the water column.  However, neither of these actions will kill weeds and algae directly (not even pond dyes with EPA registration!).  The only pond dyes that can kill algae or weeds are pond dyes that add copper products or herbicide products to the mix.

This leads us to why these pond dyes desire to have an EPA registration, since no pond dyes actually kill anything.  The only reason that a company would desire to acquire an EPA registration for its pond dye would be to send the message that its dye will kill weeds and algae.  This would make it appear to be more effective than other pond dyes, and would allow it to make a kill claim on the label.  In reality, the mode of action is exactly the same as all other pond dyes.  The only difference is the ability to claim that blocking sunlight actually kills weeds and algae.  And this claim comes with a fairly expensive price tag.