I bought this pump, bayite BYT-7A015 DC 12V Solar Hot Water Heater Circulation Pump with DC Power Supply Adapter Low Noise 3M Head 8LPM 2.1GPM https://www.amazon.com/dp/B01G305PK0/ref=cm_sw_r_apan_glt_fabc_1W7524DKGYWH039HT8PY?_encoding=UTF8&psc=1, and attached some heat resistant tubing. If it flows to fast I just turn off the pump. Pretty simple really.
bayite BYT-7A015 DC 12V Solar Hot Water Heater Circulation Pump with DC Power Supply Adapter Low Noise 3M Head 8LPM 2.1GPM https://www.amazon.com/dp/B01G305PK0/ref=cm_sw_r_cp_api_i_AZwuFbXB9TF61