Here is what I found on Tropica Specialised:
See how Specialised Nutrition with nitrogen and phosphor is easily and exactly dispensed with the included pump.
Contains nitrogen and phosphor for fast-growing and demanding plants
Also contains iron, manganese and vital micro nutrients
Suitable for aquariums with many and fast-growing plants
How to use the product
Specialised Nutrition is added each week when the water is changed. The pump bottle dispenses 2 mL per push.
We recommend 6 mL (3 pumps) per 50 L water weekly. However, we recommended that this is set in accordance with plant requirements. Specialised Nutrition contains, in addition to micro-nutrients, all essential macro-nutrients. The fertiliser is particularly suitable where plants display a lack of nutrition. However note that if algae growth starts, Specialised Nutrition will promote this growth.
Specialised Nutrition contains nitrogen (N) and phosphorus (P). Dosage must therefore be adapted to plant absorption rates, to avoid undesirable algae growth. Where signs of algae growth develop, reduce the dosage by 50% and increase water changing frequency by 50%. Changing the water not only reduces the concentration of nutrients in the water, but also removes algae spores, remnants and other accumulated elements from the aquarium water.
As you can see, no mention of potassium (K) even though it claims to have "all essential macro-nutrients".
Are you possibly on the 'wet coast' of Canada (Vancouver / Victoria) or do you use a water softener for the water in your tank? What I see seem to be 'soft water' related issues including possibly magnesium and calcium. Here is what I suggest:
1) Continue dosing your current nutrients and doing water changes as you have been.
2) Pick up some Seachem Equilibrium which is a GH Booster containing potassium, calcium, magnesium, and lesser amounts of other nutrients.
3) Do an initial dose of 1 teaspoon per 10 gallons
4) Thereafter, when you do water changes, add 1 teaspoon of Equilibrium per 10 gallons of new water added
5) Now the hard part....................wait.
Watch the new leaves as they emerge and mature. Do they look straighter, healthier, possibly with better color, and also possibly a faster growth rate (although even healthy Anubias as slow to begin with). More importantly, as these new leaves mature they should not develop the white flecks that become necrotic. They should also remain much straighter without the curling leaf margins and leaf tips that you currently see. Remember, watch the new growth....the existing leaves will not improve and may continue to decline.
Questions just ask! Keep us posted as things progress! -Roy
Potassium deficiency symptoms first appear on the recently matured leaves of the plant (not on the young, immature leaves at the growing point). In some plants, the first sign of potassium deficiency is a white specking or freckling of the leaf blades. With time, the symptoms become more pronounced on the older leaves , and they become mottled or yellowish between the veins and scorched at the margins. These progress inward until the entire leaf blade is scorched. If sodium cations are present and taken up in place of K+1, leaf flecking (necrotic spots scattered on leaf surface) and reduced growth occur. Potassium is phloem retranslocated from old leaves to new growth.