HansDig
A Fixture
Sounds a bit like Woodland Scenics "Realistic Water" then. It also seems to take a day or two to clarify.
Magic Water is crystal clear when poured, unless you choose to tint it, and is great for still water. To depict running water, I've started using Aqua Magic for depth and then a layer or two of Magic water on top.
I'm now pretty interested in giving the Vallejo products a try for waterfall features though - your one certainly looks convincing.
Yep, it's nice stuf and works easily. You can also use it to make rimples in the water so first you use the still water and let it get hard and then you use the water texture 26.201 to make rimples or small waves. Very realistic when you have some rocks in the water etc.