Thank you for your comments. Yes of course, you have correctly identified the potential problem of pH being to high (the fish are goldfish and Koi, also a good population of frogs, newts and toads). If I do go ahead, I have a variety of carnivorous plants to experiment with, including S. Purpurea. But, I was wondering if anybody had already tried and what were the results. I believe the Irish populations of S. Purpurea are causing problems due to their illegal introduction, with the CPS. organising regular clearings. On that note, I will need to clarify my position with the appropriate authorities.