Maybe it is just the late hour . . But I"m a bit confused. Is the acre a holding pond or is than an acre of garden?We collect rain water. We store enough to gravity water a dozen head of cattle, 100 head of sheep, rabbits and 100+ chickens, plus several gardens totaling about an acre. So yes, or tanks are large. It's amazing how much rain just one metal roof can collect with only an inch of rain.
We don't ever add anything to our tanks. Instead, the ones that ever have any sun hit them have large gold fish in them. This keeps the algae down no problem.
The largest tank which gravity feeds the house has well water instead of rain water, so it's a dark tank that light does not penetrate.
Are these plastic tanks? HOw long to they last?? as in durability? Is the dark tank just a panted tank or a dark plastic?