The missus did wonder about the ecover stuff.
Good call on the pump out, although most do rinse with a bit of water afterwards so im guessing that will push the blue into the tank.
Thanks everyone for your help, Trevor Preece directed me to seaglaze and identified it as a trident catch, after several emails going in seaglazes spam folder i finally got to speak to them and a tri catch kit should now be on its way to me.