Thanks Ed, I think I was only keeping the Microsiemens (electrical conductivity / salt content) at around 300 because I was breeding discus at the time. The higher the salt concentration in the water the less success with the eggs hatching etc. Here are some pictures of the Riccia Fluitans in my tank that I took this evening after doing the 50% water change this morning 3 days post EI dosing. It looks pretty promising so far. I will keep you guys posted. Many thanks for all the words of wisdom!! Steve.