I've been attempting to keep live plants for 18 months, and use Seachem Flourish liquid fertiliser plus root tabs (previously API, currently Easylife root sticks). Plants survive for anything between a few days and a few months. Sometimes a plant almost seems to be thriving but a change in location in the tank or another plant overlapping it causes a demise. Sometimes a plant such as anubias can be perfectly fine kept in its pot but, when transferred onto wood, dies swiftly. Some plants have thriving top leaves but the leaves underneath look as though they're nutritionally malnourished eg manganese, iron, potassium, magnesium, etc, judging by the plant diagnosis charts. Other plants have lower leaves thriving but the upper leaves almost look as though they've been burnt by the lighting. Sometimes floating plants have a slight smell as though they've been singed by the lighting. Black beard algae takes a hold on many of the plants.
While flicking through some aquatic magazines lately, I noticed a couple of articles - one on substrates, one on using a pair of old tights to act as a plant pot. Apart from the plants which can be grown on wood, I keep my plants, along with their rock wool, in the black plastic containers which they come in. I was thinking that, if I bought a suitable nutrient-supplying substrate, I could perhaps attempt growing some plants in this inside the tights (fastened at the top with a loose cable-tie) and buried in the existing substrate rather than either changing the entire substrate and rather than continuing with the plants-in-original-pots route - this would give the plants a better chance than them being constricted in their existing containers.
Reading the article about substrates, it looks as though complete substrates contain a lot of nitrogen-based compounds including ammonia which would be a risk to my fish given that my tank is already stocked, as well as soil reducing PH ?and water hardness; would these also apply to Seachem Flourite and Caribsea Eco Complete which are not soil-based but instead fracted clay gravel? Layered substrates appear to be an alternative option, possibly better in my case?
Any views/thoughts on the above? Any potential problems, especially with my very soft water? No risks to my fish and snail are paramount!
Thanks.
[Subsequently edited to correct the name of my liquid fertiliser - for some reason, I keep calling it by the wrong name!]