I've been using GG4 for a couple of weeks, I dint know if it helps or not really, I think I could do with putting more in, I'm putting 1ml per 100l at the moment. Have you noticed and improvements using it Dave?
I've been using 2ml per 100l for the last week and a half. Certainly froths well and bubbles on the glass.
In my mind I think it's working and feel that when I can't see the bubbles that it's not. I think the finish on the glass is superb.
But that's the thing because I
think it's doing wonderful things I'm reluctant to leave it out. I certainly haven't noticed a detrimental affect at all but can't definitely say if there is an advantage or not. We all know pure water is fine anyway and this time of year everything cleans up quicker.
Cleaning agents and detergents are used to clean everything else so I would imagine the clean would be improved if only by a little.
It's a bit like when you buy the latest brush from Gardiners - first couple off days and I think
WOW! this is superb. Then I buy another one. Six months down the line and I have a bad day and the brush gets blamed so I try another flavour of the week

I used to love the soft black Extreme they made then I loved the mixed dual trim etc. These days I love the stiff dual trim and everything else is in a pile on the van floor.