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My L333's produce considerable waste. My L046's produce very little waste. Number and size of fish are very close. Amount of food given is the same. Each has same size bare bottom tank. It's a head scratcher as to the lack of waste on the L046's. They eat real good. Anyone else notice this?

Often, the longer a fishes intestine, the more waste it produces because it has evolved to gather food from nutrient-poor sources. It'll be subtle, but I suspect that L333 eat nutrient poorer food in the wild.

Jools

Beyond what Jools suggested-

While the two fish may currently be of similar size, they do not end up that way. 333 gets larger. That being the case it grows more and this may mean it needs more food to do so. There is length and then there is bulk. 333 likely are bigger bodied than zebras when they are both the same TL.

Next, the smaller a piece of poop, the faster it breaks down in a tank. Is it possible the poop size from zebras is smaller and that some of it is dissolving before you see it?

Finally, how far from the filter intakes do both fish tend to stay? If the zebras are closer to the intakes maybe more of their poop is sucked up?

Then there is also the possibility that your estimate of the amount of poop for each species is off. Are one's poop of a given size more dense? How do you measure the amount of poop?

Both tanks have the same aquaclear filter with a pre-sponge on the intakes. Both receive the approximately the same amount of food. I guess as suggested, the consistency of the poop must be different and one is being picked up by the filter.
There's really nothing wrong here, it's just a little weird. The L046 pooped more at an inch long than they do now at 2-3 inches long.