Chemistry
Dilution notation (1+1, 1:1)
How the mix of concentrate and water is written: “1+1” means one part concentrate plus one part water.
The plus sign adds up the parts: 1+1 is half concentrate and half water, and 1+9 is one part concentrate with nine of water. A colon is sometimes used in the same way, but it is often read as the ratio of concentrate to the total, so check the datasheet when a dilution is written 1:4. A dilution changes the development time.