1. expensive per volume of media/ In the UK a litre of matrix is around £16-£17 and substrate pro is £12-£14,how is that more expensive per voloume.Yes I am well aware that seachem say you only need 500 ml per 200l of water,How can seachem say such a thing without knowing the stocking type of setup and various other variables.
2. Needs to be replaced according to eheim/I have eheim media that is over 8 years old and still doing fine,I think it is more a marketing thing re replacment.
3 has not been shown to colonize anerobic bacteria to be effective in nitrate reduction./The only people I have seen stating this is seachem with a study that they commissioned which said there media was the best and had more surface area than any of the others and that it had the right size pores for anerobic bacteria.I would be interested to see anyone that has used matrix pro for the purpose of nitrate reduction in a canister filter setup
4 clogs faster especially if you follow eheim filtration setup in canisters./how long do you go between cleaning your filters? I clean my eheim 2078e once every month and I have not noticed any reduction in flow due to media clogging.
It's still a good media on smaller setups, I would class it in the same boat as bio max.
Most people consider substrate pro to be one of the best media's available,and there are a fair few eheims running eheim media that have no problems at all.I would imagine that if there media was only good on smaller setup there would be a lot of people with problems with water parameters because of using eheim media.
I have personally used eheim media for as long as I have been keeping fish and have never had any problems with my water parameters in that time.