As Ann stated if you use HC110 as Kodak wants the developer will not last 6 months. I use a lot of HC110 and I generally use dil B. I make dil B by using one oz from the bottle and 31 oz of water. Stir well. That will make dil B. HC110 will last a long time if used this way. You don't state the brand or type of film you are planning to use. I would run some tests. As a starting place for Tri-x 6.50 minutes seems to be good at 68degrees f. good luck