If you have bittered to 23 l then yes you should!!
To work it out have a look at the this, copied from another brewer
16L of 1.078 from 4.2kg of grain and 0.2kg of sugar (which is to style), should dilute to 26L, the dilution formula I use for a target OG of 1.047: 78 / 47 * 16 = 26.5. I...