Blanched means dunked in boiling water for a few mins, then ducked into cold of a few more, prior to feeding. IMO blanching of cucumber is not needed, so long as you have enough weights to hold it on the bottom.
HTH
rabbut
No boiling is required but look on E-Bay or google a device called the screwcumber, dead simple but dead effective way of delivering cucumber to your fish
My fish adored cucumber I had lots so they ate it very quickly I used to make crudites and they all swam to the top and it was chomped on all day. I rarely ever removed it as I reckon the plec used to hide it in his cave as all except the Balas and Gouramis went in there.
For the black moor, I would try peas (very lightly boiled and deshelled) and sprouts. Also lettuce, spinach, chard.
Not all fish need vegetables in their diets- corydoras aren't really fussed- but many plecs do, and livebearers also tend to do well on this; I feed mine veg twice a week, just whatever we're having really.
OK you guys have really baffled me i didnt know fish could have cucumber.
Chunks or slices ?
i have got 14 barbs a parrot fish a silver shark and a loach will they all eat it