GMGC45L Clay Pebble Grow Media – 100% Natural Expanded Clay Pebbles for Hydroponics, Aquaponics & Indoor Plants – pH Neutral, Great Drainage & Aeration, 1.5 Cu. Ft. Bag

Best growing medium.

Just wash it first, great price for rocks, great for a soil additive if you don't wanna use perlite and a lot of groves for micro organisms to live in if you're using compost tea

Works well for hydroponics. I've had this stuff in use for months and only a couple pieces ever sank. I would not recommend this for any sort of pond use or drainage in potted plants as it will always try to float.

Man, is this stuff expensive. I've been using this in a backyard aquaponics system for almost a decade now. Pros: works perfectly for DWC hydroponics, still works well for aquaponics, is cheaper than hydroton. Cons: still very expensive; figure 6 bags to do 10-12" in a chop-and-flip IBC aquaponics system, so a few hundred dollars easily, splits when frozen into tiny sharp pieces that WILL wreck your pump after they make it through your filter, and they are very "dirty". That also means you have to buy more, as they don't work with siphons when they're that small. You will also need to rinse these several times, or you will have tons of silt in your system.

Great for plants

I mix it with the hole Indognti provide extra drainage.

These have a ton of dust. They literally took six clean rinses to run clear enough to trust with a hydroponic flood/drain system. Not a deal-breaker, but be aware. (The rinse is still not clear, but the murky gray dissipated "enough".) DO NOT rinse these in your laundry sink unless you have the plumber on speed-dial. This is an outdoor activity, which precludes starting in the winter in many climates. Definitely a summer project.

I wish the overall size of the pebbles were larger but not a big deal. Such a great volume for the money. I get a new bag every so often. A reliable choice for me. Use for hydro as well as in planter bottoms and as cover.