I have heard of people using a little bit of a commercial product called Salt-Away in rinse water to thoroughly remove ocean mineral residue and prevent that whitish buildup on camera housings. The effective ingredient is sulfamic acid, which is sold as a cleaner at places like Home Depot. When sufficiently diluted it is safe, non-toxic, harmless. The Salt-Away label says it is effective even at 1:500 proportions.

I'm taking a trip soon with a Kraken rinse bag so I'll have a chance to try it on just my own gear when rinse and soak options are limited. To save weight and space I might take the crystal version instead of liquid Salt-Away. An old film canister full would probably last me the whole two weeks. Four ounces of the 99% reagent version is about $12.

Has anyone here used it? Here's the wikipedia entry: https://en.wikipedia.org/wiki/Sulfamic_acid

I would not use that unless you had a seriously encrusted item, like something recovered from the ocean and allowed to dry out. Damage to orings and the finish would be my concern.

Simple fresh water soak and lightly working the buttons is enough to keep a housing and other great in good shape.

Use an Lp inflation air blower on a tank to help dry stuff off.

The problem is not removing salt deposits, the problem is that the water you are soaking in has dissolved salts in it and you are adding to the salt by adding another type of salt. It will help dissolve scale, but the whitish buildup on housings etc is not a buildup of mineral scale. It is formed by allowing rinse water to dry out on the surface. As the water evaporates the salts become progressively more concentrated until they begin to etch the anodizing of the housing.

Anodizing is just developing a thick adherent Aluminium oxide coating on the housing and the colour is from dyes incorporated into the coating. The coating resists corrosion , however strongly acidic or basic solutions can begin to dissolve it and may also react with the dyes.

The solution - as Dave says - don't let water evaporate to dryness on the housing. Blow off droplets and wipe dry when most of the droplets are blown off. This can also remove excess water from inside the buttons and help prevent corrosion of the button/lever shafts and springs. No additives needed.

I’ve noticed many times that Nauticam housings seem to show discolouration much more than Subal. All the Subal housings I’ve had still look good as new even after hundreds of dives.

I can’t imagine Subal owners by default are more careful with post-dive care. Quality of the anodising?

1 hour ago, TimG said:

I can’t imagine Subal owners by default are more careful with post-dive care. Quality of the anodising?

Normal Subal housing are silver gray. I guess the black anodising is more susceptible to discoloration.

P.S.

I'm that guy with a completely whitish Nauticam housing 😁

4 hours ago, TimG said:

I’ve noticed many times that Nauticam housings seem to show discolouration much more than Subal. All the Subal housings I’ve had still look good as new even after hundreds of dives.

I can’t imagine Subal owners by default are more careful with post-dive care. Quality of the anodising?

That is probably from hard water deposits. I don't have hard water where i do most of my diving and my housings don't seem to accumulate those deposits or discoloration.

Good question, and I suppose the answer would have to consider the effect (short and long term) of Sulfamic acid on O-rings.. Perhaps someone from the housing makers will have done those tests?
Personally, apart from the final rinse that I give at the resort, I dump my housing (and all other housing/torch/...) in hot water in a clean tank when I return home from a dive trip. Usually two rounds.
Also, that little bit of whitish patina -- I don't think it's harmful, and is a visual cue about the experience for the housing.

Kind regards,

Ajay