If my soil is too pourus do I need more nutes?

I have one plant that was kind of an extra that I threw in a pot with whatever soil I had left over which was mostly generic potting soil that didn't seem to have much actual dirt but mostly other organic material. I didn't give it much thought cause it was just an extra, through the growing process I noticed the "soil" wasn't holding much water but it's an indoor planter with a large plate to catch any runoff.

As it turns out this is my nicest and largest plant. This plant has defied all basic growing logic as it's in a small container with poor soil. I water top down until the dish is about 3/4 full and it generally sucks that up in a day but the soil retains almost no water. I'm a few weeks from finishing and I want to keep feeding her but there seems to be a little more yellowing of the fan leaves then it should have and I wonder if I should be feeding it more nutes? I would say it's growing in a quasi wick type system.

It's been very hot this week nearing 100 each day and cooling a lot at night. It's maybe 3-4 weeks from finishing or maybe sooner as the flowers have grown relatively fast. This is the purple hair plant so it is definitely a different genetic then any of my others.

was it soil conditioner? if it was ya very little retention. no clay or other solid matter. feed it dont be scared !!!!!!

It was a bag of very generic "organic" soil mix, looked mostly like small wood chips with very little actual dirt, it was barely enough so I tossed in some more lava rock which is supposed to retain water within the rocks. I can tell you though whenever I water it the water runs straight through the soil.