(Please refrain from answering if you do not own or have built one of these troughs)
I am going to build an insulated box for one horse trough and a solar box for another.
One box will be superinsulated and the other will have a simple do-it-yourself solar panel.
I was Googling this on the web. One web site BuildItSolar: Solar energy projects for Do It Yourselfers to save money and reduce pollution had some interesting plans. The whole link is www.builditsolar/projects/water heating/solarhorsetank/solarhorsetank.htm.
My boxes will be painted black for some passive solar.
IF you have made one of these boxes or have a solar heated tank or insulated tank please let me know if you have any tips.
If you just don't like it because that is just the way you are. Please refrain from commenting.
Ps I am not interested in any electric heaters or water tank addititives, just solar and insulation.