For a 'recycled tub' implementation, you can easily source a water pump from an aquarium supplier, if they sell gear for salt water aquariums they will most likely have large enough pumps.
Nevertheless, and I hope this sounds constructive, this is the kind of topic that you should really be discussing with an occupational therapist or child psychologist with experience in autism.
For some topics the internet can be a terrible place for advice.
Nevertheless, and I hope this sounds constructive, this is the kind of topic that you should really be discussing with an occupational therapist or child psychologist with experience in autism.
For some topics the internet can be a terrible place for advice.