Do I need flourish

[ScotJudd]

I have a 270l heavily planted tank with fish and RCS. I have 2 x 42" t8 tubes ( one for plant spectrum and one for fish colours). My specs are temp 27C, Ph 7.2, ammonia 0, nitrite 0, nitrate 5, Kh 6, Gh 6. I use standard dose of excel every morning. I use co2 injection for 10 hrs to attain 15ppm by the late afternoon. (Switched off at night when air stone comes on ).
Plant growth is extremely good but I have notices a few yellowing spots on some of the older leaves. So my question is, do I just remove these older leaves, it will not make much difference to the overall dense planting or should I start with a weekly fert such as seachen flourish. As I have RCS in the tank and have been advised that these are not affected by careful dosing of flourish. My preference is to leave alone and trust in the fish waste and ammonia and nitrates to fert the plants. My nitrates stay at 5 all the time so I assume that the plants are taking up a fair bit. I do about 20% WC once a week to freshen the water even though the water is within tolerance to replace used up minerals.
I am asking for serious thoughts on where I go from here. Leave alone and remove affective leaves or add flourish.
Your opinions please........
Just noted pic doesn't show yellow patches very at all but they are in the early stages but it seems to be on the older leaves. New growth is normal colour.
Ps. Can someone identify the large reddish and tall green plant for me. They look to just be a different colour variant of the same plant. Cheers.

 

[Rivercats]

From what I see in the pic's you mainly have crypts which are heavy root feeders. If you get some root tabs and use them as directly your crypts will get the nutrients they need. You can also cut any yellowing leaves off so the plant doesn't waste energy on them.

You should do a large WC weekly regardless of tank parameters. There are many different toxin and nutrients that can build up in the tank, ones that can't be measured, so by doing a 50% WC weekly you ensure all toxic buildups are kept at a minimum.

 

[ScotJudd]

Thanks for your reply. I'll look into root tabs. And thanks for the plant ID.
I will also try and increase the WC's.
Steve.