Rain water for goats?

So i have noticed copper lost in my goats and i have given them some copper based off there weight but they gave me trouble so working on that but i found that if the water you have like well water is high in sulfur and iron and calcium it can bind the copper still making it an issue. well my well water has all 3 of these things so aside from buying gallon water from the store now i and lookin into collecting the rain water off the goat barn but what has to be done to ensure its good enough for my goats to drink? i know if its in a clear then algae can grow so a dark contaier is needed like the ones they sell online for rain spout collections is there anything else i would need for this? i would plan to empty it regularly and clean it to make sure no algae is growing. I just want to make sure my goats are getting there copper and if this extra step is what is needed to help reduce the amount of well water they get ill do it.

That's interesting about the compounds in some water binding with copper.  Goats do need a lot of copper!  And goats can also be very picky about drinking water!  There's likely a correlation.  

Rain water sounds like a good idea.  If you have a clear/white drum you can just paint it blue or black or berm it with substrate or straw.  Burying/berming it will help keep it cool, too, in the summer.  

Another alternative is to find a good loose mineral that's really high in copper.  I've only ever found it in locally formulated loose minerals.  Big name brands like Mana-Pro are really low in copper.  And just let them free-feed on minerals as needed.

In my goats, signs of copper deficiency in the past have been hair turning white, "fish tail" (hair missing on tip of tail), and increased parasite loads.  Loose minerals have corrected these things throughout the years.

I dont collect rainwater yet, but I do use mini barley bales that I found online in their water troughs. They keep algae down pretty well. I have found them several places. This is just the first one I found right now to show you.

https://www.chewy.com/summit-clear-water-barley-straw-pond/dp/153111?utm_source=google-product&utm_medium=cpc&utm_campaign=hg&utm_content=Summit&utm_term=&gclid=Cj0KCQjwqs3rBRCdARIsADe1pfRLzLI-m6WXOMvXWFbZ6wwOwUIplPu-U3pBwzk626avkMc_N9nQf1AaAr-CEALw_wcB

Well water = over mineralization that could have negative  effects over the longterm.

Rainwater = under mineralization that could have negative effects over the longterm.

Spring water =just right.

The above is a summary from Zach Weiss in regards to human water needs. I thought it worth mentioning.