I also have some Seachem Flourish, excel, potassium, nitrogen... on
this site. (i just use them whenever i remember ...
so dont count on this)
WTG Shrek! Nice aquarium.
How long a photo period do you have? You might try increasing it by an hour or two. That is another way to get more light to the HC. Is it possible to lower your light fixture? That will also increase the amount of light the HC gets.
However, your "when I remember" fert scheme - similar to my own, a while back - could be another reason to explain the HC growing tall. HC is one of the plants that really pearl when growing well. Are you experiencing that? If not, you need to get a better handle on fertilization. And if I might make another suggestion, the ferts you are using are expensive. There are considerably less expensive ways to buy fertilizers.
The three fertilizers I have settled into are:
Seachem's Equilibrium (which has trace amounts of K, Ca, Mg, Mn, SO4 and Fe). Assuming you use it only in your 29 gallon tank, one 600 gm/1.3 lb jar ($10.50) should last you over two years. I also use Potassium Nitrate (KNO3) and Mono Potassium Phosphate (KH2PO4) that I buy by the pound at
Planted Aquarium Fertilizer One pound of KH2PO4 ($5) will last you well over 2 years, and a pound of KNO3 ($3) will probably last you at least a year -again, if you use them only in your 29 G.
For a 20 gal tank I use 1/32 tsp of equilibrium, 1/32 tsp KH2PO4, and 1/8 tsp of KNO3, about 3 x a wk. And I do at least one 30 - 40% water change each week. I don't have a PO4 test kit yet, but I keep my N between 5 - 10 ppm... and with the above scheme, my HC pearls every day. In fact, if it stops pearling, I check my N levels and usually find that they have dropped to near zero. Another shot of KNO3 starts them pearling within a few hours.
Just a few thoughts... is all.
