Australia's Science Forum

Hello,
Has anyone ever had the problem with their water distillers when it gives out water with the PH5, It's old but working fine, but most of the time cannot use because of this problem.
Is there a way to clean or try and fix this problem. Can anyone give me any hints?
Trish. Lab assistant/ Maintence repairer.

Hello Trish,

I am not sure that there is anything wrong with your still. Distilled water rapidly dissolves carbon dioxide from the air to form carbonic acid and will often end up with a pH of 5 - 6.

I don't test the pH of the distilled water, just test with Silver nitrate solution, to make sure that each batch is OK - sometimes some sort of reflux happens and contaminates the distillled water. If it is clear with the silver nitrate added to a small sample, then the water is OK for use.

I agree with the other replies. But also, have you cleaned it out? I use about 4M Nitric acid to clean mine and it gets all the build up off the element and makes it work more efficiently. I probably only do this about twice a year, if that, but I notice a difference in the output of water afterwards. The only thing is to make sure after cleaning that it is rinsed well enough before starting it up again.

Thanks guys, I have never cleaned it out, to tell you the truth I never knew we could or how. My teachers complained about it having a ph5,so I thought something was wrong. I thought it had to be ph7. Anyway will give it a clean as suggested and see what happens.
Many thanks Trish.

I know we explored this on another thread, but do you really want to run a distiller and waste all that water? I buy de-ionized water from a car battery factory for 50c a litre, in 20L lots. Easier, pretty cheap - cheaper than supermarkets or even hardware stores - and environmentally friendly.

Or get a Millipore filter. Stills are causing sea-levels to rise.