Swapped Seachem Matrix for lava rock, can't tell a difference

[sarah_2891]

So I've been running Seachem Matrix in my FX4 for like two years. 75 gallon, heavily stocked with cichlids. Nitrates always sat around 20-30 before water changes, which I do weekly. Nothing crazy.

Ran out of Matrix during a rescape and didn't want to pay $30 for another tub, so I grabbed a bag of landscaping lava rock from Home Depot for $5, smashed it up with a hammer, rinsed it forever. Threw it in the same media baskets. That was three months ago. Nitrates are literally the same. Maybe even a touch lower but that's probably just because I added more pothos.

Not saying Matrix is a scam, but for the price difference I'm struggling to justify going back. Anyone else using lava rock long term? Any downsides I'm missing? I know it's heavier and can trap more gunk but I'm not seeing it yet.

[FilterGuru]

Man I love this experiment. There's something really satisfying about smashing up $5 worth of rock and getting the same result as the fancy stuff.

I did almost the same thing in a 40 breeder about a year ago, but I used the red lava rock from a landscaping place. Word of warning though, some batches of that stuff can leach iron and give you a weird rusty tint if you don't soak it long enough. Mine did for the first couple weeks. Did you notice any discoloration or did you get a clean batch?

The gunk trapping thing is real long term imo. I pulled mine after about 8 months and it was basically a nitrate factory in the baskets, way more mulm than the Matrix ever held. So you might be fine now but keep an eye on it around the 6-8 month mark.

Also your point about the pothos is probably doing more than you think lol. I added a pothos wall to my 125 and my nitrates dropped like 10ppm without changing anything else. Plants are sneaky.

What's your pH sitting at with the lava rock in there? Curious if you're seeing any drift.