Well good buddy !!! Think we have been down this road b4. used underpants Ive been told do not go near media which has been used in a MARINE TANK. Now l know your's was tropical ? Please tell me if it was marine. I need 6lts of the stuff to go in a eheim 2229 wet dry filter recently bought from Vicky n Kev. See l do buy things (sometimes). I really need to spk to someone in the trade who can give me some reassurance on this matter. Will tell you by Thursday if lm up 4 it. Is there any chance in you can weigh the tetra media and do you think i can get the tetra sponges to fit the ehiem ?? Thanks Trev. Ps you say you also have some new eheim Mech pro ? If yes put my name on it, Im sure we can work out a price which makes us both as l say if i can use it i will take it. TrevI'll get back to you Trev. Eheim Substrat Pro and Eheim mech is not new, but has been boiled beyond belief. Eheim Mech pro, siporax and the TetraTec media is brand new (apart from two Tetra sponges as specified).