Pre-rinsing Tri-X 120 format gives black water?

[CronoZero]

Hi everyone!

I just started using Tri-X film with my Holga (challenging myself to compose and expose correctly), and I've noticed something that never happened when I used HP5 in 35mm.

Usually I give the film a pre-rinse in the development tank before I pour in the developer, but every time I've done this with the 120 Tri-X, the pre-rinse comes out black/purple.

1. Is this normal for either Tri-X or 120 black and white film?
2. If so, should I skip the pre-rinse step with this film/format?
3. If not, any suggestions on what's happening/ am I damaging the negatives?

Thanks much!

 

[bob338]

i always pre-rinse and it's always the same black/gray water you describe. it's recommended with a rotary processor, but i don't know if it is necessary with a hand tank.

 

[pau3]

It is normal. It is the antihalation coating that dissolves into the water.
In fact, Kodak advises against prerinsing in small tanks, but many people
- including me - uses this method. In my case, I use it to bring the tank and
films to the developing temperature.

Best,
Pau

P.S.: in fact is Ilford who warns against presoaking, claiming that it
can lead to uneven development.