@Darryl Thanks for reaching out!
We have several good options for hydration day packs that should meet your needs. Here are a few:
- Osprey Skarab 30 Hydration Pack
- REI Co-op Trail Hydro 30L Hydration Pack
- Gregory Citro 30 H2O Hydration Pack
Some of these might be a little big in terms of the pack itself, however, if you're looking to carry 3+ liters of water you will appreciate the structure of the bigger pack. Some of these do come in a smaller version, but it is good to bear in mind that the hydration bladder also gets smaller.
Hope this helps!