What "substrate" do you currently have? I recall you mentioning Seachem Fourite Red? It's good to have both ferrous (Fe2+) and ferric (Fe3+) iron sources. The latter especially for the heavy root feeding iron hogs such as certain Crypts for example, but realise that with red clay (as with Flourite Red), it is not in the readily available form. Over time it is broken down by means of biological or photochemical reaction. Adding a thin layer of earthworm castings on tank bottom and capping it with the Flourite Red will both help seed (through CEC) your Flourite Red as well as speed up this process. As too will adding Flourish Excel or Scape Carbon for its iron reducing capabilities, but know that you still need to be dosing Fe2+ to the water column as this is a readily available form and easily absorbed through plant leaves.
I have some narrow leave swords growing at a nice rate leaves nice and green but occasionally the tips of the leaves turn yellow all tough i am using sera florenette a root tabs. thinking that it could be a iron deficiency and that these root tabs is just not cutting it. ironically these where the only plants that survived after my tanks was smashed up in a burglary a few weeks ago
Brand name aside, there are other alternatives just as good or better. But yes, if you think your plants have an iron deficiency, then you need to up your dosing. What ferts or fertiliser regime are you currently using?
for the moment just liquid ferts seachem comprehensive. do you think the yellowing on the tips of my narrow leave swords could be a iron deficiency.
The yellowing of the leave tips is only on my narrow leave swords. but then again they are heavy root feeders.