Sadly the ikea dimmer didn't do the trick, it just flashed on and off so have raised the tile to 30cm above the tank although I think it is still too much light. Keeping an eye out for second hand controllers. I will change the title of this journal as the puffers are now on their way down to Dean, in England, as are the lampeyes. They can kick their heels up in his 350l tank. Both my tanks are now shrimp only.
The hygrophilia pinnatifida is growing slowly but surely and is so attractive I would like some in my other tank. The round pelia is growing fast but the hydrocotyle sp 'japan' can't seem to grow faster than the shrimp eat it so is at a stand still.