Should I be using filtered water when caustic/acid cleaning?

[Judd]

And the two hour, hot, double strength acid wash did absolutely nothing.

[Judd]

Lots of views...anybody got any ideas?

[Ted Briggs]

is your "caustic" actually PBW? If so thats your problem- switch to 5star "heavy-duty recircualtion cleaner"

[Judd]

is your "caustic" actually PBW? If so thats your problem- switch to 5star "heavy-duty recircualtion cleaner"

Negative. 5 Star HD caustic #2

[Greenbushguy]

Why are you using Chlorine Dioxide sanitizer in a stainless steel vessel? I don't know if I would trust it unless I knew it was pure ClO2. It could have other acidic things in it that would make it NOT good for stainless steel. That may be part of your problem. It'll destroy the protective coating on the steel and also possibly cause it to start rusting. If that's the case the only way to fix it is re-passivisation. Probably with Nitric/phosphoric acid blend. Pure Nitric acid are best for passivisation but are NASTY to use.

[dick murton]

I suspect the white streaks are now formed from calcium phosphate, not calcium carbonate. You will therefore need to carry out a special descaling clean with something like EDTA to get rid of them. Once formed, normal formulated caustic tends not to get rid of deposits.

Check the formulation of the caustic is suitable for your hard water - it may not have enough additives in.

Stop hot rinsing with hot water. This is where a lot of the problem arises, as the CaHCO3 degrades to less soluble CaCO3 due to the heat. If the water was soft, you could quite easily get away with hot water, but why waste energy on hot water? But the water needs to be sterile.

Softened or RO treated water for CIP - definitely - to avoid a repeat of the scale formation.