John!(posted 8305 days ago)HC-110 stock solution is 1 part HC-110 and 3 parts of water. To make dilution B take 1 part of stock slution and 7 parts of water. This means that dilution B is 1 part of HC-110 and 31 parts of water! I think that, but I'm not sure, that 5-7 minutes will give you good starting points for T-MAX and TRI-X for example. I use HC-110 1+50 and have a couple of more minutes. 20 degrees C. /Lars