blanket weed controller : FAQs

hi guys, hope your all well, looks like were getting round to the time of year were the blanket weed is starting to go mad,. i have been looking a buying a blagdon electric blanket weed controller, it clames that it will control ponds up to 23000 litres 5000gal, any one used one of these things and had any joy or are they just a waist of time and money thanks for any help on this one:D:D