I have quite a few friends who use Matrix exclusively and the results are mixed. I have read hundreds of posts hearing people’s individual results and it’s always the same. There are plenty of people posting their positive results very similar as what you’ve seeing and then the typical naysayers who saying it’s a poor, overpriced biological filtration medium compared to alternatives like sponge or Moving Bed Biofilm Reactors (MBBR).
I started the Maxspect on July 1st so it’s been roughly 80 days. I do envy your Lamotte as I don’t trust my interpretation of the API color chart so I’ve been having my local reef store test my parameters every 7 days using theirs. My water change schedule is 50% every 3 days. I started having my water tested every week from June 1st to June 30th to have a baseline. My nitrates hovered around 14.5-17.5ppm prior to a WC. I should note this tank has 10 Oscura Heterospila roughly 5-6”(it’s been two years, I hate these fish), 10 Amatitlania nanoluteus, and originally 100 plus Hyphessobrycon pulchripinnis(lemon tetras) that I’ve lost a few so I’m guessing 90ish.
According to Maxspect the Denitrification catalyst should be replaced after 60 days which I did. The catalyst is very inexpensive at the cost of $7 every 60 days. My current nitrates are now averaging 9.5-11ppm so after 81 days I’m seeing roughly a 30% reduction in nitrates. So I’m pleasantly surprised so far. Now my concern is Maxspect also recommends cleaning and or replacing the blocks every 6 months which is sort of confusing. It takes time for the anaerobic bacteria to colonize so I emailed this past Monday as to confirm why I would replace the blocks as it seems like a scam to sell more products. I don’t mind buying the catalyst as I understand the bacteria needs a carbon source but I am skeptical on the need to replace the blocks every six months. They do note to only replace half as to not wipe the bacteria completely. I will continue using them until December 31st and then tallying the final results but so far I am pleased.