Quote Originally Posted by karthik View Post

Should I try to rectify the over-concentration issue by diluting the solutions further?

--- Karthik
I would advice to mix a new batch of fixer. To strong a solution will probably not hurt, but I would not risk it, especially with what you describe about the fixer bottles having a white sediment on the bottom. Something else that I did not completely understand from your explanation is when you mixed the working solution. You said that the bottles have stood for about 6 months since the faulty mixing. If your work solution fixer was sitting in a bottle for 6 months it is probably time to change it anyhow.
Ilford states on their factsheet :
Full, unopened bottles of ILFORD RAPID FIXER
concentrate stored in cool conditions, 5–20C
(41–68F), will keep for two years. Once opened
use completely within six months and keep all
bottles tightly sealed until used.'