There's this brief article at the big, much-visited French site "Cichlidae"
http://cichlidae.netliberte.org/ by Michael Negrini and Robert Marcel, which I translate:
"The superb Hypancistrus zebra comes from the Rio Xingu in Amazonia, but like many Loricariids the hardness of the water has little importance. It has even reproduced in hard water. It's very important to put some roots in the tank where they are kept because they need them for their bowel movements.(Mine spend long hours gnawing on roots.)As for price, I've bought them for 270 Francs but I've heard of H. zebra going for 150 Francs (see how to buy a Loricariid). My first Zebra went from 5 cm to 7.5 cm in three months; the second gained a centimeter in a month and a half. They get along well with Parancistrus sp. "Magnum" (L 47) and with Leporacanthus galaxias (L 7) in a 450 liter tank with Lake Victoria cichlids. You should avoid fishes that will harass them, either because of their size, like Glyptoperichthys gibbiceps, or because of their aggressivity, like Pseudacanthus leopardus (L 114).
"As for feeding it's not difficult from the moment it hits the bottom; mine eat
pate maison* and cucumber (boiled for five minutes). I've never seen them eat algae off the glass or off the rocks."
*
Pate maison: a blended mix of veggies (peas, carrots or spinach) with an equal part of lean fish, shelled mussel flesh or whole shrimp, with some spirulina powder added, mixed with unflavored gelatin, to keep fragments from getting caught up right away in the filter.