VDB questions and a growth in my ferric ammon citrate

[eddie gunks]

i am once again having difficulties with my VDB solutions. several months ago. i was told to put some tartaric acid in my solution and warm it to 120 degrees to get rid of solids in my VDB solution. (there was a url link here which no longer exists).

well i used up that solution. it worked. i had a great time and made some good photos. now i am mixing a new batch.

this time i heated my distilled water to about 160. mixed in my chemicals and then mixed a+b and then added c to that mix. i had no solids till i added C to the mix. the solution was still warm so i added two pinches of tartaric acid to it and it seems to have worked again.

why is this happening? is there something different i should be doing? should i start with a bit less tartaric acid and add the difference at the end so i am consistently using the same amount? thanks.

one more question. i have mixed a kallitype solution. i have not tried it yet (one thing at a time) and i notice my ferric ammon. citrate has what looks to be mold floating in it. what is that? could it be mold? it is only about 45 days old in a brown bottle stored in the dark. any ideas?

thanks again.

eddie

 

[smieglitz]

...
why is this happening? is there something different i should be doing? should i start with a bit less tartaric acid and add the difference at the end so i am consistently using the same amount? thanks.

one more question. i have mixed a kallitype solution. i have not tried it yet (one thing at a time) and i notice my ferric ammon. citrate has what looks to be mold floating in it. what is that? could it be mold? it is only about 45 days old in a brown bottle stored in the dark. any ideas?

thanks again.

eddie

eddie,

Try adding the silver nitrate at a slower rate. That may help, but your situation is fairly common. Lots of folks ask about the precipitate and how to alleviate it. Adding more tartaric acid seems to do the trick.

As to the Fe. Amm. Citrate, yes. Some sort of mold loves the stuff. If you filter the solution it should work just fine. To prevent the mold you might try adding a bit of thymol solution (or Listerine which contains thymol as an active ingredient).

Joe