Slice cucumbers lengthwise into eighths.
Combine cucumbers and 1/4 cup salt.
Cover with cold water in large container; let stand for 2 hours.
Drain; rinse well with cold water.
Combine 1 cup water, vinegar, pepper flakes, sugar, onion, garlic powder, pepper and 1 teaspoon salt in large pot.
Bring to boiling point; add cucumbers.
Return to boiling point; reduce heat.
Simmer for 8 minutes.
Pack in hot, sterilized jars; seal at once.