δεν γνωριζω αν ειναι ελαφροπετρα αποδεδειγμενα.αλλα ακομα κιαν ειναι,δεν ειναι οι μονοι.και η seachem "βγαζει" το Matrix που ειναι ελαφροπετρα.
"Seachem Matrix
Description: Processed pumice. Seachem has taken pumice, broken it up, smoothed the edges and washed it. It is guaranteed free from heavy metals and silicates.
Surface Area: Same as pumice above.
Advantages: Ready to use, reasonable surface area
Disadvantages: Expensive, will slowly clog.
Cost: Expensive
Best Use: Trickle filters and Canister filters."
http://www.fnzas.org.nz/?p=1778
εσυ που θες να το βαλεις? θα προτιμουσα το substrat pro για κανιστρο.