Yes if its the only one?
Black Ghost Knife Fish are semi-agressive. They should be fine though. The angelfish should be fine.
A knife is the best choice. You can use scissors though but its cut will not be as fine as the knife's.
I have got an Adolphus Bush knife with the green pee hole, actully looking to sell it.
Vegetable slicer. If it is not available, you can use your knife . Be sure that your knife is very sharp for fine slicing
In order to cut foodstuffs into very fine shreds. (Cutting this fine would be impossible with a knife. )
Knifes get large and the Discus require REALLY clean water, but should be fine if proper water care is administered. Use Bio-Chem Zorb or Chemi Pure to help retain crystal clearness. Knife would be the only concern as, a) they get larger and b) they most often need to be fed live feeder fish which will diminish water quality.
Betta fish don't even think about goldfish they need 10 gallons each. If your bowl is bigger than 1 gallon a betta will do fine. Below 1 gallon get a ghost shrimp or snail
I have found that if I use a sharp knife, they are pretty easy to scrape off! My pocket knife works just fine.
a knife
Any chef's canvas knife case will work fine with the Forschner 46892 3-Piece Chef's Knife Set
Ten gallons for two or three is fine.
There is a museum that claims to have the knife of Jack The Ripper. If you 'read the fine print' you will find that it is not the knife used by the Ripper. There was never a weapon recovered in this case. In what remains of autopsy reports of the Ripper's victims it can't even be determined as to the exact type and size of the knife used.