Eheim Substrat Pro vs Fluval Biomax

[cvar]

My canister filters are filled mostly with Eheim Substrat Pro. But 20 years later, the sintered glass Substrat-Pro balls are much smaller, crumbling, and slowly disappearing. I suspect the BB bacteria have less room to live in the worn down Substrat balls? Perhaps it's time to replace them? But replacement cost of Substrat Pro is very high. Biomax seems so much cheaper. But will Biomax last nearly as long? Or will Biomax break down quickly? I'm not keen to replace the stuff very often. Substrat Pro is sintered glass -- effective, long-lasting stuff that works well. I have not idea how Biomax is made, nor how it might last. Is Biomax as good as Substrat-Pro? Your thoughts, please?

 

[FJB]

Bio max is made in a similar manner. Even if there may be quantitative differences in surface area of equal masses of the two materials, the difference is not huge and most people (or did, or tank) will notice. Long way to say just as good.

 

[deeda]

I substituted Seachem Pond Matrix for the Eheim Substrat Pro in a couple of my large Eheim Classic filters as it's cheaper and I noticed no difference in either how the filter operates or bio capacity.