Thanks for the tips everyone. Have just had all of the tests done on the water and all is great with that. Nitrates, phosphates, carbonate hardness, all is well. Could it possible just be a case of over feeding ???? I can be very heavy handed with the food as I feel guilty giving them such a tiny bit as advised ???? Or possible that it maybe changing sex, I read on here that that can cause the erratic behaviour. , Oh I do have the live rock and the coral and it was all circulated for three weeks before any fish were put in. They were all doing well until I put the phosphate resin in the filter to get rid of the red algae.Thank you all I appreciate all of your input, it is nice to be able to get advise from others who not alot more than this little minow.