Natural Algae Control Pond Balls 300ml Pet, Fish and Wildlife Friendly

Bought these to clear the algae in a nearly new water feature. Resevoir is 23cm deep, 90cm wide and 40cm tall, supplies an Oasy 30cm wide blade with a fall of 60cm (first world problems). 1/4 of this should have obliterated it. It didn't touch the sides. 1 week later. I gave the benefit of the doubt so removed plants and blitzed with half a tonne of chlorine. Managed to kill the 106 year old neighbours, I apologise. Started afresh and tipped the rest of the pot in to keep the algae at bay at the expense or the plants (plants remained) but the algae won again in less than 7 days... realised I've been totally mugged off. Minus 5 button!! Enjoy 🤘