Sharon,
I believe that these are all HDPE plastic ciontainers (High-Density PolyEthylene). I don't think that this plastic is recyclable so they will not have a recycle code. They are usually not intended to be re-used, or recycled in the way you may think. This type of plastic cannot be reformed into another shape. It is what they call "thermo-set" which means that once it is made into a molded shape, that it cannot be ground down, reheated and reformed into another shape. However, since HDPE plastics have certain qualities like non-absorbance of chemicals, they are prized for reuse in their original shape such as a barrel or a drum. That is our (pond peoples) prize. You can clean them or purge them of all the previous chemicals and reuse them for just clean water and fish and no harm can result if you did a good job in the cleaning. Other plastics can absorb chemicals and no matter how well you clean them, they still expel the chemicals that were contained within them. Kinda like a sponge. HDPE doesn't absorb chemicals like that or in that way, so as long as you rinse them thoroughly, you are good.
If we have a plastics engineer here, I will be happy to be corrected on my statements as I am not so certain of them (the recycling and thermoset part anyway). I work with a lot of different plastics, but I am not an engineer in that area. So please forgive me if I have made a mistatement.
Catfishnut