We made this water wall from different PVC pipes and funnels. We tried many different ways of hanging them on the wall(don't mind the Christmas paint we have not taking fully off yet) but in the end making tape worked just fine. Water play is great for kids. This wall allows them to manipulate water in different ways and is good for practice hand/eye coordination. You could always add some add-in toys and let them play with things as they please. Few of our add-in toys were little fish,balls and nets. So my kids could try to catch the fish's and balls they went threw the pipes.
Either way just remember to let them have fun, When they play they learn~