Rare Earth by General Hydroponics is another silicon product. It's cheap and it works well, but it's a dry product. It's a really fine power so it probably won't clog things up, but at least a portion of it seems to never dissolve. For systems that have small-bore pumps/emitters, there is a "filter sock" that comes in the tub. But it tends to not last all that long, so you'd want to make something a little more durable if it's a concern.
And "a little dab will do you," lol. I've used the stuff in cannabis grows, the rose garden, the (other) herb garden, and both vegetable gardens and still only go through a small tub in a year. I don't follow the directions so much as just sprinkling a little here and there, but even still... I once put about half what was recommended into a DWC and went away for two days; while I was gone the pH spiked so high - from using too much silicon? - that the entire garden looked like I'd hit it with industrial-strength defoliant. And it wasn't one of the
vegetable gardens, either <DOH!> I've read (and experienced) that some GH products are fairly dilute. Apparently, this isn't one of them.
Hey,
Irish Boy, you have to cut a hole in your floor yet, lol?