First off, let me say this stuff is STRONG. I used it in my 5,000-gallon pond and learned the hard way that a little goes a long way. My pond went from crystal clear to looking like the entrance to a black hole with just 2 fl oz! While it was darker than I intended, the effect was actually pretty cool - like having my own private infinity pool.

The dye works exactly as advertised for algae control. My pond used to turn green within days, but with this dye, the water stays clear for weeks. It's amazing how just a small amount can treat such a large area - the 4X concentration is no joke. I especially love how it makes the fish pop against the dark water when they come up to feed.

Application couldn't be simpler - just pour it in and watch it disperse. No complicated mixing or measuring needed. Though I'd recommend wearing gloves unless you want blue hands for a week (speaking from experience here).

The only downside is the staining power - be careful not to spill it on clothes or surfaces. And if you have a smaller pond, definitely start with just a few drops at a time. It's much easier to add more than to deal with water that's too dark.

Customer service is fantastic too. When I had questions about dosing, they responded quickly with helpful advice. For the price and results, this is hands-down the best pond dye I've tried. My pond has never looked better!