Adjusting pH of RA4 developer

[Fatih Ayoglu]

Hi all,

So when I was replenishing my developer, it looks like I have put too much replenisher in the seasoned bottle and now the pH is around 10.7 which I’d like to take back to 10. What should I add? Just simple water or Dev Starter?

Also a separate question, to increase pH, I should just add more replenisher right?

Many thanks,
Fatih

 

[koraks]

Acetic acid tends to work well for pH down. The acetate seems to not interfere with the developer in my experience.

Increase pH by adding NaOH or KOH.

 

[Fatih Ayoglu]

Acetic acid tends to work well for pH down. The acetate seems to not interfere with the developer in my experience.

Increase pH by adding NaOH or KOH.

Thank you so much.

Is the target pH 10 universally accepted for every manufacturer? I use Tetenal Monobath.

 

[koraks]

Is the target pH 10 universally accepted for every manufacturer?

No, it depends on the specific product. Fuji's RA4 developers are generally between 10.25 and 10.35, but it varies with the exact type. Just follow the specifications for the actual chemistry you're using.

 

[Fatih Ayoglu]

Ah ok?, sadly Tetenal has not published its required pH level.

I guess the only way to figure out is, preparing a new mix from unopened bottles and record it

 

[koraks]

That might work.

But does this particular developer actually come with a starter? I.e. isn't the replenisher the same as the working strength developer? In that case, I don't see how you'd overreplenish if you just add correctly mixed developer. Or did you add too much concentrate? If so, do you know how much you added? You could then just dilute with the correct amount of water.

 

[Fatih Ayoglu]

That might work.

But does this particular developer actually come with a starter? I.e. isn't the replenisher the same as the working strength developer? In that case, I don't see how you'd overreplenish if you just add correctly mixed developer. Or did you add too much concentrate? If so, do you know how much you added? You could then just dilute with the correct amount of water.

According the instructions, I can prepare a working solution either from Replenisher + Starter or Concentrate + Water + Starter. In 1 litre working solution, both ends up with the same quantity of developer at the end.

I think what I have done it is; because I have not used the working solution for like 2 weeks, I have taken randomly 200ml of it and add 200ml replenisher. Previously I have printed 2x 12x16 and few 4x5 with it.

This is the product https://www.freestylephoto.com/104512-Tetenal-RA-4-Color-Developer-Replenisher-CD-R-SP-160-4-X-10L

 

[koraks]

Oh, it's a replenisher/starter kind of thing.

I think what I have done it is; because I have not used the working solution for like 2 weeks, I have taken randomly 200ml of it and add 200ml replenisher.

From a total volume of how much? 1 liter? 2.5? 200ml isn't all that much. I wouldn't expect this to be a major issue. Have you tried just using it as is? There may be a little drift due to the over-replenishment, but depending on how exacting your standards are, it's possible that it's not a real problem.

 

[Fatih Ayoglu]

Out of 1 litre. The prints are coming ok actually. Maybe slightly magenta, that's about it

 

[koraks]

In your place, I'd just dial in a little magenta on the filter pack and keep printing...since the replenishment rate is something like 160ml/m2, I'd just do 8 more 16x20 without replenishment and then start replenishing again according to specifications. In the meantime, you may see a little gradual color and density shift. This is annoying if you want to replicate the exact same print between different sessions. But in a more usual amateur setting where you print different images and color balance them one by one, it's probably not a big deal anyway.