We did the Algeria - Crystal Pool hike a couple of weekends ago, beautiful and lots of water points but yes definitely a longer walk (especially going up Groot Hartseer) but Crystal Pools is just so beautiful
Wolfberg trip this weekend was amazing, my first time there so obviously blown away by the arch and cracks and the surrounds, we were also lucky being alone at the Arch until after sunset. I emailed Sanddrif that we were planning the trip and organised overnight permits from Cape Nature for the Arch and then for parking your car at the cracks and hiking up there we got permits early before our hike at Sanddrif. Apparently you can also organise telephonically would you want to start early but we had to still drive in from CT and they open at 8am.
And yes, there was water 2.3km from the Arch towards Gabrielskloof (so 4.6 return). Not a lot but good enough to refill and apparently there is a bigger pool 2mins walk on but we wanted to head back to the arch so can’t confirm on that one.