Just weighing in, I am a sand bed person, I run a 4 inch sand bed and siphon the top 1/2 to 1 inch with regular biweekly 20% water changes. Its a mixed 90g reef tank I have had for about a decade, although I moved it 5 years ago and replaced the sand at that point. Softies, LPS, and SPS, 7 fish (fox face, 2 clowns, lmb, coral beauty, cleaner wrasse, dragonet) and I feed heavy.
I built my rock work specifically to eliminate dead spots, which can become "nitrate factories" when stuff piles up. I run a gyre pump which is well worth the $ and the sand stays put with relatively high flow. I run a biopellet reactor, a skimmer, and occasionaly carbon, and dose 2 part. I run T5s supplemented with some Kessil a80s for shimmer.
Occasionally I run into issues with my nutrients being too low and delay water changes.
Ive been in the general aquarium hobby for 18 years and have had a ton of tanks, fresh, salt, fowlr, reef - with all you just have to fine tune not just your setup but your maintenance regimen, and then stick to it and avoid new gimmicky products, esp additives. So many additives are just worthless snake oil, or hurt more the help.
I find problems usually occur when I drop out of routine or make too many changes at once - long vacations with bad pet sitters, new relationships, other hobbies popping up, extended power failures, adding too much new livestock at once, changing too many methods of export at once, or when something big like a clam dies and goes unnoticed for a day.
