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Connect a blumat system to a rain barrel or water storage tank.
Just screw half on the inside of the tank, the other on the outside. The nipple connects to the standard blumat 8 mm water supply/feed line.
You can either start with one of these bulkheads, or a blumat pressure reducer–either of these fittings will "start" your blumat watering system. blumat Classic Jr and blumat xl do not require either.
Use 1/2" drill bit to puncture hole.