How do I heat or cool the Chemicals???

[Wayne]

Oxygen is the enemy of all developers.

 

[focus_on_infinity]

My darkroom can be cool, and my chemistry might be at 64-65F right out of the bottle. That's enough to affect development times, so I use a mug warmer to get it up closer to 68-70F. https://www.amazon.com/Coffee-Warmer-Beverage-Birthday-Black-2/dp/B08VVWZZ2J It just takes a few minutes. If the air temperature is 65F, it takes quite a while for it to drop significantly, so I generally don't need to re-warm it.

I also recently picked up a plant warmer pad https://www.amazon.com/certified-Seedfactor-Waterproof-Germination-Hydroponic/dp/B074753J5V, because I thought I might be using it with trays some time. I haven't tried it yet.

 

[cliveh]

Best method I have ever used:-

How to Develop a 35mm Black & White Film with a developing solution of 1:1 with water

Developing solution – You will need 150ml of water mixed with 150ml of developer = 300ml for each film (I know it says 295ml on the tank , but 300ml is easier to remember), double quantity for 2 films etc. The mixture of developer and water should ideally be at a temperature of about 68oF/20oC.

Pour 150ml of developer into a measuring jug and measure temperature. If it is under or over 68oF/20oC, make a separate jug of water to compensate for the difference. Example – if the developer temperature is 18oC, make the water to 22oC, before adding 150ml of water to the developer. Thus giving you a developing solution at 20C/68F.

 

[Sirius Glass]

Why the oxygen thing???

Oxygen can kill some developers in a few days.

 

[voceumana]

Just as oxygen can combine with steel to produce rust, it can combine with the developer ingredients to change them to lose their developing properties--it is called oxidation, and is like when your cut fresh potatoes or avocados turn brown if exposed to air.

 

[jvo]

i have been fortunate to have darkrooms where my bottled chemicals were always stored in areas that were approximately ~70F. I would determine the temp of the developer and use the appropriate length of time for a properly developed negative.

for storage i use glass bottles and topped off the fluid with an inert gas, (tetenal protectan, or paint store product) - oxygen gone.