Let me start by saying this dye is POTENT. I poured what I thought was a 'moderate amount' into my 5,000-gallon pond and within hours, it looked like I'd created a portal to the underworld. The transformation was instant - my previously visible koi now appear as mysterious blue shadows that only materialize at feeding time.

The good? This stuff is MAGIC for algae control. Where I used to battle string algae daily, now I just enjoy my moody, reflective black mirror of a pond. It's like having nature's sunglasses - the water stays cooler and my fish seem way more active since they're not getting sunburned.

Pro tip: WEAR GLOVES unless you want Smurf hands for a week. And maybe don't wear your favorite shirt while applying - that blue stain isn't coming out (ask me how I know). For smaller ponds, use an eyedropper - this concentrate could probably color the Pacific Ocean if you're not careful.

What surprised me most was how it changed my pond's entire personality. The black creates these incredible reflections where trees double themselves perfectly on calm mornings. It's like having a living oil painting in my backyard.

Would I buy again? Absolutely - but next time I'll measure carefully instead of eyeballing it unless I want to explain to neighbors why my pond looks like it should have Loch Ness Monster sightings.