Three strains, all have the same problem. Please help

Three strains, AKxWW, NL5xHaze and SuperSkunkxNL. I had the same problem on my first grow. This is my second. I'm using Sunshine #4 soil, 6 gal square pots with drainage holes. RO water, GH 3 part nutes with Big Bud, Bud Candy, Voodoo Juice and Cal/Mag when needed. I fertilize every 3rd watering and I don't water until the pots get light. Currently under 750w HPS lighting, was set at 1000w but I thought maybe I was bleaching out the leaves. This doesn't appear to be the case since the problem is continuing. The problem is worse at the tops of the plant. The NL5xHaze iis about 4 weeks into flowering. The buds are developing nicely and are green but the rest of the leaves are suffering. The leaves are a bit more yellow than they appear in the photos. My first grow produced okay and the quality seemed good but by the end the plants looked horrible. Any help would be appreciated, please let me know if more info is needed.

it looks like a nute burn from too much fert or a nute lock out just flush your plants with 3 x the amount you container with the plant holds , i have 5 gal buckets so i flush with 15 gallons and my leafes on my white widdow also did the same around 4 weeks too and my ak-48 is starting i think its too much fert like i did and the start of it closing ooff and finishing off flowering.

There may be other issues, but using the SS#4 mix, did you add any lime? Either dolomite or garden?

That's a peat based mix and if no lime was added, your pH is probably out of whack and cal/mag issues to boot because of it.

~$5 for a 40lb bag at Lowes or HD, plenty cheap and that bottled stuff isn't going to do much for your soil pH.

Wet

Thanks for the replies. I didn't add lime. I'll pick some up. That's probably what's going on.

Looks like spidermite, check the under leaves. Looks nasty.