What's going on with my fan leaves?

I'm running (6) Pineapple Trainwreck from clones, and they've developed a problem I can't identify and correct. Anyone else ran this strain, before?
Pineapple Trainwreck from clone, transplanted when rooted, and immediately sent into 12/12- and they went apeshit!
They are exactly 4 wks into bloom- 28 days.
FF Ocean Forest
10% perlite added
1 cup dolomite flour per cubic ft
1-1/2 gal pots
DG bloom nutes (50% strength 1st feed, 66% after)
400w hps
RO water, ph'd to 6.5 +-
During the first 2 wks in the Ocean Forest, they only got ph'd water, then I started in with the nutes. Shortly after (about a week ago), started noticing these necrotic spots on the fan leaves, and it has continued to progress. Best I've been able to diagnose it has been a (P) deficiency, but am afraid of burning them up if I overdose them. Should I have been feeding these from the beginning?
I'm also running CheeseQuake with the exact same regimine, and they're doing great!
Input please!

The ultimate potting soil—everything your plants need, in one bag. Ocean Forest® is a powerhouse blend of premium earthworm castings, bat guano, and sea-going fish and crab meal.

Composted forest humus, sandy loam, and sphagnum peat moss give Ocean Forest® its light, aerated texture. Start with Ocean Forest® and watch your plants come alive!




I can see how the the magic ingredients and pretty colours sucked you in . It might work with veges but not with dope. The brown spots are salt burn which you get in these soils with all that acidic ferts in there. When you add nutes god knows what happens.

Use a coco mix like this with coco hydro nutes and you wont have these issues anymore.

*BUDS said:

The ultimate potting soil—everything your plants need, in one bag. Ocean Forest® is a powerhouse blend of premium earthworm castings, bat guano, and sea-going fish and crab meal.

Composted forest humus, sandy loam, and sphagnum peat moss give Ocean Forest® its light, aerated texture. Start with Ocean Forest® and watch your plants come alive!

I can see how the the magic ingredients and pretty colours sucked you in . It might work with veges but not with dope. The brown spots are salt burn which you get in these soils with all that acidic ferts in there. When you add nutes god knows what happens.

Use a coco mix like this with coco hydro nutes and you wont have these issues anymore.

Click to expand...

I follow and respect your train of thought, and I don't have the experience to rule it out, but I've had excellent results with the FF OF mix, before. Just not with this strain.
Main reason I question this is, I have the mother in the same mix, and she's doing great. Seems if it were salt burn, the clones would've burnt right up when planted. But they went crazy, much like anything else I've put in that mix.
Thanks for takin' time to input!

Anyone else?