Hi I have a pair of angels in my 180 litre tank nothing else in the tank . They have laid eggs twice last time they got to the wriggler stage before the female ate them . Three weeks on and all they do is what looks like fighting every time the male goes near the female they lock mouths ? Not showing any signs of spawning again do I separate them and try the female with another male or do I leave them . All water tests are fine nitrate 0 nitrit 0 ammonia 0 ph 7.2 ? Help please