water stains in syphon tube

[lazydog]

i have a couple of different syphon tubes they one i use to attach to the tap to fill Fv is stained inside even when cleaned with a bottle brush and sanatised it does not come out i have used it for ages like this as i treat the water after it is in a spare FV prior to using it to top up my brew.
So is normal for plastic tube bought from a HBS as food grade to stain?
Could this be hard water stain?

 

[piet_v]

i have a couple of different syphon tubes they one i use to attach to the tap to fill Fv is stained inside even when cleaned with a bottle brush and sanatised it does not come out i have used it for ages like this as i treat the water after it is in a spare FV prior to using it to top up my brew.
So is normal for plastic tube bought from a HBS as food grade to stain?
Could this be hard water stain?

Could be, yes.
Used to have the same problem.
Got rid of it after i used (by change) an acidic sanitizer on my tubes/siphon.
Now i use acidic 1 in 5 times and don't have the stains anymore.
Don't ask me for scientific explanation.

 

[Vossy1]

Is it stained white? If so it's most likely calcium deposits, though other minerals contribute.
As p_v has suggested a soak in acid will usually get rid of the residue, though it may take quite a soak to get rid of a decent amont of deposit. The problem with deposits is if they flake of when beer is passing through the tube, the area under the flake has likely not been sanitised. Soaking in a concentrated citric acid (lemon juice) solution should do the job though it will probably be best used warm. Failing that, phosphoric acid is commonly used in brewing and dairy parlours for the same reason.
If using standard pvc tube it may be cheaper to simply replace it.

** always use acids with care**

 

[lazydog]

cheers folks
now i know what to do i will buy new and treat it regular just to be safe