Mushroom farm - monitoring system

I find a high pressure pump :http://viewitem.eim.ebay.pt/12V-Volt-Mini-DC-Diaphragm-Water-Pump-65PSI-3Lmin-RV-pump/330893776704/item

the problem is that my misting system only can handle pressures between 220 and 280 kPa... there is some way to reduce the pump pressure?