I cannot find any info on the product you are using (I checked their website, nothing). Can you provide a link to the ingredients, or list them if they are on the label?
While waiting for that, I will mention that aquatic plants require 17 nutrients in order to photosynthsize. Some of these are macro, some micro. Some will occur from water changes (primarily the "hard" minerals like calcium, magnesium, and a few lesser), most can arrive in fish foods (the fish waste if left in the substrate will be broken down by snails and bacteria into nutrients the plants can take up), and some occur naturally like hydrogen, oxygen and carbon (carbon as CO2 is the by-product of the breakdown of organics, its main source, and lesser from fish, plant and bacteria respiration).
The other important factor is light. Light must be of sufficient intensity to drive photosynthesis, and different plant species have differing requirements here. The nutrient level must balance the loight; if it doesn't, the plants may be hindered and algae will take advantage as it is no where near so fussy. From the photographs, I would think the light is fine. Also, I like your aquascape too, nice work there.
When I know what ingredients are in this product, I may have more, or can suggest something else if I feel it necessary. What were the red plants that you said did not last? Red-leaf plants require more intense light, generally, because red is an essential wavelength for photosynthesis but red leaf plants reflect red light, to look red, so there needs to be more. With higher light comes increased nutrients, and here is where CO2 may become a factor in limiting these plants. I find it best to determine the light, then use plants that are suited; much the same as selecting fish suited to your water GH, it makes life much easier for all.
Byron.
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