I have seen LECA at our Petsmart, (we also don't have any hydro stores near where I live) I have also ordered LECA online, it is surprisingly lightweight, so shipping is not as bad as I thought it would be.
-The LECA at Petsmart, is in the reptile habitat section (ppl use it at the bottoms of their Vivariums/Reptile enclosures for drainage purposes and to encourage beneficial microbes (~microbes? or whatever they r called... I don't remember) to grow & live there, they take care of the waste produced) at least in my Petsmart, it is with the coco bedding, sand, etc. the "Substrate" section of the aisle
Hope this helps!
I'd love to see pics of this mini! I love minis too