Pepsi Max addiction

[GJABS]

Cola contains loads of phosphoric acid. Sodiumbicarbonate would bring the pH a bit up, sodium hydroxide pallets would be better,you need less of it but you have to be more careful to handle it.

pH meters are generally available, You need to regularly calibrate pH meters though. litmus paper would be much easier and cheaper to use

Yes I've been having a play with some litmus paper (universal indicator paper) from my schooldays chemistry set, and it gives a reading of ph=6 for the Pepsi Max, which I think is a little high - it says online that the Ph of diet coke is 3.
First I have tried putting a rennie tablet (containing Calcium Carbonate) into it (Ph of around 8 or so), but it does not seem to be dissolving, and must therefore only be effective against stronger acids. Calcium Phosphate is also fairly insoluble so would precipitate out.
I don't think there would be much difference between Sodium Hydroxide and Sodium bicarbonate because in the latter case carbon dioxide gas would be produced, which would escape, leaving Sodium Phosphate which is slightly alkali. In the case of Sodium Hydroxide only water would be produced by the same reaction.
I do have some Sodium Hydroxide somewhere in the garage, left over from a time in 1985 when I tried to do electrolysis on it molten (it has a fairly low melting point as compared to salt), in a bid to create metallic sodium. I blew the fuse in the DC power source unfortunately. But I digress..

[GJABS]

Stop using it NOW - it's terrible tulip, especially the "Diet" one

What is in it that makes it terrible? I am not disagreeing, as I have heard others say the same, but have not been able to find any details.