I use "Ocean Forest" from seed thru harvest and think it's the best potting soil I've found!
I believe you have a PH problem. Get yourself one of those cheap PH test kits (under 10 bucks) and check your water. I'll bet it's close to or above 9.0. But there is an easy and cheap fix for high PH...Brita Water Filter works great! It takes 9.0+ tapwater through the filter and into the pitcher at a perfect 6-6.5. I have 2 so there's less time to fill up the water jugs but until I started watching the PH I too was getting those rust-copper colored patches in the leaves, usually starting from the center and growing out to the edges. I'm telling ya, Brita Water Filter w/pitcher will solve your PH problem (15 bucks at Walmart plus you'll need a 5-pack of filters to do an entire grow)!

New, fresh cut clones should be given water only for 1st 2 weeks or until they're rooted and ready for a pot. I spray mine 3-4 times/day and keep them under a clear plastic dome to hold in the humidity and warmth (they like it around 80-85...steamy and still). It's also very improtant to use clean, PH-ed water or if not available use distilled water.

But don't worry yourself about the trace elements like calicium! You're only making it much harder than it is and trace elements will not be your problem as long as you're using top quality and fresh potting soil such as Fox Farms.