That's probably the whole point.
I used crushed oyster shells in my tanks, have for years, no algae at all in any of them.(Well, in it now that I'm down to 1) I use coral now, but only because that's what I had convenient.
Not such a joke, I've heard a lot of oldies say they used to do that back in the days of walking through the snow uphill both ways and heating the tank with candles underneath it...
It's too bad noone suggested something something like mystus or GBA. Too bad noone will suggest anything like synos or hoplos either.
BTW, first hit on google image search for striped mystus? My pic.