Gardening/anyone know what this is?

[Deleted member 1465]

And no, it's not a cookie
It's the inside of my drum of...something...
I found bags of the stuff at a fly tipping site. It appears to be some sort of inert brown silty medium containing lots of small brown ceramic balls. It's not actual potting mix or compost but it's something horticultural.
I've been using it to add bulk to soil.
I have a theory as to what it actually is but I'd like other opinions as I suspect certain members may be able to shed some light.
Zoom in and have a look. Any ideas?

 

[faraway_beach]

The clay balls look like hydroponic media, it's probably soilless potting mix.

 

[Deleted member 1465]

That's exactly what I thought re the clay balls. The brown substrate feels like powdered coconut husk or something similar. I've no way of knowing, and ofc you can't see from the pic, but I'd be surprised if it has any nutrients in it like normal potting mix does. But what do I know?
I've been mixing it with soil. Maybe I should try growing something tough like mint in just the brown stuff and see if it takes. There's bags and bags of the stuff going spare.

 

[loginboy69]

hey @Underscore the clay balls are hydroton and theyre good for the soil , and the brown stuff might be coconut coir.

i normally use hydroton for cacti since theyre really expensive

 

[Deleted member 1465]

Thanks!
I just looked up coir and I do believe you are correct. I've been mixing it in with the soil. I have a huge supply of this stuff, as long as I'm able to cart it back from the dump site in my backpack. Not an issue as it's light in weight.

I found this:

Need Help Getting Started With Coco Coir? Check Out Our Step-by-step Guide To Using Coco Coir Bricks For Plants!

Coco coir or coconut coir can be a great asset to your garden. it is lightweight, absorbent, and provides good drainage. It also helps to keep roots cool and prevents waterlogging. -- here's how to use it properly for the best results

gardening-abc.com

I now have free sources of the following:

• Coir, many bags
• A half tonne dump of silty loam soil with humic matter
• A substantial dump of clay loam
• A large amount of wood chippings for dressing
• An endless source of river sand
• A huge supply of manure
• Nicely rotting compost for mulch

The only thing I lack is gravel for potting mix. I have pea-git and sand but I want something in between in grain size for the plants that need more drainage. I shall go looking where I get the sand, I think there may be some gravel knocking around there.