Ph seems to be too high?

I re-potted my plants about two weeks ago.Then come to find out that my PH measuring meter cal. was off.The PH was too high.Now the new internodes started turning yellow.Is this from a zink proplem, and what should i do to correct this.I started follor feeding them to help with the lock out.Could some one give me some tips on what i should do to fix this problem.I'm growing in soil, and keep my PH at about 6.3-6.8 and have been giving them about 1/2 nutes keeping my PPM at about 500-600 ppm.I'm also using R/O water,but don't understand why this is happening, never had this problem before.Any ideas?Thanks

Wow, they look pretty bad, like the nutes are TOTALLY locked out. How far off was the PH? IDK what to tell you, except that a light flush with PH'ed water, then a PH'ed feeding, would be a good idea. If you get the PH back in spec, and have some nutes available, the plants should take in what they need, and not get any worse.

Well, before I calibrated my instrument, it was off by about 5 points off; ie 6.5 = 6.7-6.9 PH level or more.It didn't seem to me that it being that far off would affect them that bad.
I have been follar feeding them with grow big nuts until the soil drys up a little.Just mixing it with a small amount nutes w/ my PH at 6.3.When they dry up a little, i will be flushing with clean water and starting over.
Hopefully they will recover.

i wanna know how to get my tap water ph down iv tryed leaving it for 24hrs and it still stays at 7.4+

You really shouldn't use tap water cause of the high ppm, and calcium. if its over 400ppm, don't use it.You can use Epsom salt with the water to help with the ph,or try using alittle lemon juice.The acid in the lemon will bring down the ph also.
of buy some PH up or down from a hydro store.

I Found out that humic acid, ranging from 10% - 75% helps with the nut break down and keeps the plant from lock out, you can mix it with any nuts, or just with water.
I was told that it works very well in my situation.You can also use it as a follar feeding too.

Some tap water is okay, mine is only 35 PPM,which is quite pure. But yes, you do have to watch for hard water, which is loaded with calcium, iron, and chlorine(the worst one). Anyway, if you want to lower the PH, you can use a little lemon juice, or some vinegar. Some claim white is best, and other claim that cider is best, so I imagine that either would be fine. Better yet, go to the local Walmart and buy some 'PH down' for aquariums. Just make sure it's phosphate free, and you'll be good to go. Or, your best option would be to order a bottle off Ebay or something. It's pretty cheap, like $15 for a bottle, which'll last quite awhile.