Kind of confused by what you have going on. It looks like the drain line is split and one side shoots up into the air in a kind of diy sprinkler system? Can't tell where the other end goes. You can do this but I feel like your salt creep, and evaporation will go way up and you may end up with water slowly dripping everywhere. I'd recommend an emergency or second drain line if possible, it's not strictly necessary but can give peace of mind and make it easier to get silent flow. The pump and return line look ok you might want a vibration pad, foam mat under the pump later again for noise reduction. I'd recommend a valve between the return union and the tank so the pump can be easily removed for cleaning.
It looks like this hasent been glued up as I can see all the writing on the pvc still indicative that no cleaner or primer was used. I teach basic plumbing skills as a water plant operator please ensure you use these products along with glue once you glue up as your much more likely to get a good water tight bond.