BTA12 Triac driver circuit
My opinion the circcuit is not that good.first if I were you I will try to connect pump before triac,Bta12 most efficient when 1 pin on negative rail.Moc 3041 is not ttl logic component it simple opto coupling  ( led-diac) if the dropping voltage in between leg 1 and 2 is not enough for driving of led then diac will not work.My guess is your moc is not working propely.But again I would not use this circuit.