Brightwell Aquatics FlorinBase Laterin Substrate VF - Very Fine Granular High Porosity Clay Base for Planted & Shrimp Aquariums, 5 lbs - Ideal for Freshwater Plants and Shrimp Habitat Setup

I will try to update after long term use, but as of opening, and not really finding much about this online I thought I should describe it. The particle size I would say is a mix between a play sand and a pool filter sand, so it is fine, but not a mud when wet. It does require rinsing, but when you buy clay what can you expect. Fairly uniform in size, not to many large (as in larger than pool filter sand) particles and the smallest that I have after washing is like the fine junk that comes in play sand. I am mixing it with some coarse sand so it fit my application perfectly, time will tell how it handles nutrient uptake but out of the box it is exactly what I expected/hoped.Update, its been a few months and my initial review still stands. The substrate seems to stay relatively stable when moving plants, as in very little comes with the plant if you want to uproot any, it blends with my sand top layer as well so that is a plus. Might have some gas build up because it can get compacted but what do you expect from a clay layer, honestly can't ask for much more. Overall I will get more next tank I set up.