Question for the chemistry majors here...

[jaws7777]

And what do you contribute that too?

I guess it depends on which tank. For the most part i'd say the ridx definitely helps break down solid waste into almost a fine dust which ends up in the filter. The bigger tank boils down to getting lucky with the returns and finding the sweet spot with the gph. Both sets of returns face the middle of the tank towards the surface forcing water down along the substrate and back up towards the overflows. The one time i had to gravel vac was the week i tested the waters with some plecos that went to town on my dw. Plecos were removed and are going back to the original owner, i got to used to dropping the hose in and walking away.

 

[FINWIN]

I agree that the solid waste while aesthetically relevant is not as important as the invisible stuff released during metabolism, beside nitrate, it contains hormones and pheromones that also have effect on growth and health, so that the volume of water changed is the most important factor. If power is interrupted, some of those by products can however be seen as an oily or white scum that builds up on the surface of the tank.
Pockets of detritus can be places where bacterial colonies proliferate, so one of the reasons for my insessent vacuuming.

Definitely the case when my female BP Patch laid eggs for four days straight (but didn't eat) ...protein buildup was obvious too at the water surface, thick white foam. Took me four hours to clean out the eggs which were on and in everything. 100% w/c and filter clean was next. I believe she had a third of her body weight in eggs. The w/c's I did were completely ineffective at this time because of her output!

Lol, she's made up for it now by eating like crazy.

 

[Coryloach]

Eggs have never lasted 2 minutes in my tanks