You still clean gravel the same way. There is no easy way IMO
. You have to do it on a regular basis, or it will build up and be nasty. Also all the other problems that come if you don't keep your aquarium clean.
I can't really think of anything else, Maybe some type of sludge destroyer.
Maybe some of the salt water guy's have some tricks up their sleeves.
there really is no other way. Every time you do a water change I would be cleaning that substrate And you should be probally be doing 30% instead of 10%.
This is how clean substrate is when you take the time to vacume it. And who say's you can't vacume sand. I do it all the time. At least when I do PWC
So when you do it send us Before and After Pics.
all for sharing our hobby with me. I have learned so much, I don't know everything, and I'm not a expert. But if I can share what I have learned I'll be glad to share.