@Hendrix I had the same trouble with water with chemo the metallic taste terrible. However I found in the supermarket two cordials one lemon the other apple very good. They were free of preservatives etc all anatural. I found if I tried normal cordials or icypoles I reacted to sugar and preservatives. Normally I usually eat anything.
Thats a another thing I found fruit sorbets (in supermarket) very good for keeping up fluids.Again had to be pure ingredients before I could tolerate them.