OK, here are your first two pictures with arrows added.
In the first photo please look at:
Arrow #1, do you see the dark leaf margin? Also, notice the 'scalloped' leaf edges?
Arrow #2, do you see the downward leaf 'hook' on the relatively new leaf?
All three of these symptoms typically accompany a calcium (Ca) deficiency.
Symptoms appearing first or most severely on new growth (root and shoot tips, new leaves)
A. Terminal bud usually dies. Symptoms on new growth.
2. Necrosis occurs at tip and margin of leaves causing a definite hook at leaf tip.
Calcium is essential for the growth of shoot and root tips (meristems). Growing point dies. Margins of young leaves are scalloped and abnormally green and, due to inhibition of cell wall formation, the leaf tips may be "gelatinous" and stuck together inhibiting leaf unfolding. Stem structure is weak and peduncle collapse or stem topple may occur. Roots are stunted. Downward curl of leaf tips (hooking) occurs near terminal bud. ammonium or magnesium excess may induce a calcium deficiency in plants... calcium deficiency
Differentiating between calcium and boron deficiency symptoms: When calcium is deficient, there is a characteristic hooking of the youngest leaf tips. However, when boron is deficient, the breakdown occurs at the bases of the youngest leaves. Death of the terminal growing points is the final result in both cases.
In the second photo please look at:
Arrow #3, do you see the new leaves emerging almost white in color?
When new leaves emerge almost white in color that typically indicates an iron (Fe) deficiency.
I. Symptoms appearing first or most severely on new growth (root and shoot tips, new leaves)
B. Terminal bud remaining alive. Symptoms on new growth.
1. Interveinal chlorosis on young leaves.
a. Interveinal chlorosis on young leaves with larger veins only remaining green. Necrotic spots usually absent; however, with extreme deficiencies, young leaves are almost white and may have necrotic margins and tips; necrotic spots may extend inward. potassium, zinc or copper excess can inhibit uptake of iron. High pH may also induce iron deficiency....iron deficiency
Iron deficiency symptoms are similar to those of magnesium deficiency, but iron deficiencies occur in young leaves first: Iron accumulated in older leaves is relatively immobile in the phloem.
I thought possibly since APFUK uses EDTA chelated iron as the iron source in their trace elements that possibly you had a high pH which impedes the availability of EDTA chelated iron. Since that is not the case with a pH of 6.5 I suspect increasing the dose of trace elements will resolve the problem. I would suggest increasing the current dose by 25% and hold that level for two weeks. Watch the new emerging leaves, if they look better, but still whitish increase the dosage another 25% and wait two weeks. When they look a more normal green that should be your normal dosing level.
As for resolving the calcium issue you can use a GH Booster like this offered by TNC
. Add sufficient to increase your tank hardness by 2.0 dGH. If you do a water change add sufficient GH Booster to the new water to increase the hardness of the new water by 2.0 dGH.
The good news is because both calcium and iron are immobile nutrients as soon as you start dosing then the new leaves as they emerge should start to show improvement; the existing leaves will change little if at all.
. Don't change anything else that you are currently doing. Over the next two weeks watch new leaves as they emerge, they should look straighter, healthier, greener, and it is likely the growth rate will increase as well. Let us know how things progress of the next two weeks. Hope this helps! -Roy