I don't want to spend too much on biomax and there is the cheaper bio-glass from odyssea (China made). I am wondering how good it is compared to biomax.
Here is the link to the cheaper bioglass:
http://www.aquatraders.com/Odyssea-Super-Porus-Bio-Glass-p/46013.htm
Here is the link to the cheaper bioglass:
http://www.aquatraders.com/Odyssea-Super-Porus-Bio-Glass-p/46013.htm