Never store chemicals in food containers -especially water bottles- use instead pills/medicine ones. Remove the old labels and put them in the dishwasher: some will be deformed or collapse, a quick and effective way to both clean the lot and check if they are safe for use. You can also buy containers from a chem supplier, cheap ordinary PP square wide-neck bottles range from 0.4EUR to 1.5EUR and are available with the capacities of 25, 50, 100, 250, 500, 1000 and 2000mL.
I suggest you buy 3-4 of the 1000mL ones for systematic storage of abundantly available reagents (copper sulfate, sulfur, sucrose, sodium chloride, sodium carbonate...) and 4-5 of each size, except the 2000mL, which is too large and heavy.

labels on plastic labels on glass
cheap expensive
can be permanently stained won't stain or alter
not fragile very fragile
content may be altered by light if amber, content won't decompose
ideal for bases ideal for acids


GHS label for citric acid

You should label your containers with at least the formula and the concentration. More elaborated labels can be prepared for long-term or systematic storage of a chemical that keeps being used and refilled. Elaborated labels should resemble the industrial ones showing name, formula, concentration, basic data, H(azard) phrases, generic dangers and incompatibilities (maybe some useful info too). If you get empty/used chemical bottles keep the labels in case you'll have that substance one day.

This is a template originally made by Lambda-Eyde which I've edited according to the new GHS system (you can find the original post with the old EU hazard symbols Here). All my reagents are labeled this way, I just print the labels with reduced proportions (for example 70%) depending on the size of the container and tape them on it. They fit square PP bottles really well but they can be also used on glass.