Stunted Growth On Staurogyne Repens

[RainboWBacoN420]

Staurogyne has become one of my favorite plants in the hobby, I love the way it looks, it made a wonderful foreground plant in my 15 gallon. For the longest time, even before I began CO2 injection, it was thriving! Just growing like a weed. Then a few months ago, I would say back in the beginning of October, maybe, the leaves just began to deteriorate. They became brown and wavy, wavy as in melted tissue paper. The stems were fine, still green and healthy, but not producing any  leaf growth. So I had thought it be a deficiency in nitrogen? Nitrates are at 0. So I upgraded in lighting and fertilizer. I was using API: Leaf Zone, then added the use of Seachem: Flourish. Nothing seemed to help. 
So I killed them....
 
Kidding, I trimmed them pretty nicely, though. I thought trimming them back would encourage growth, but for a couple of months now.... nothing. I mean there's teeny tiny little leaves growing in at the top, but just barely. It seems like it's struggling to produce new leaves and grow. So yesterday, I went to my job, and picked up some Seachem: Trace Elements. Now, I went into trusting what the bottle had said. It had listed the nutrients present in the substance, "Cobalt- Used for Nitrogen fixation, same as nitrogen deficiency signs (stunted growth)". So now I'm just waiting and hoping.
 
So here's the question, if all fails, what else can I possibly do to revive the staurogyne, and get it back to thriving as it did before?
 
I really don't want to get rid of it, it's been there since the beginning, and I love it as a foreground plant in my tank. But if push comes to shove, I'll have no other choice but to replace it... thinking cardinal plants? Or maybe even trying dwarf baby tears. Not sure yet, I'm mainly focused on getting the staurogyne back to a thriving state.
 
And before anyone asks (because I know you fish people love asking), here's a list of all my tested parameters: 
Ammonia: 0 ppm
Nitrites: 0 ppm
Nitrates: 0 ppm
pH: 6.6
Copper: 0 ppm
GH: 70-80 ppm
KH: 70-80 ppm
 
Much appreciated! Thanks! 

 

[jag51186]

What's your lighting?

 

[RainboWBacoN420]

Marineland: LED Light Strip.
-234 lumens
-7800K
The lighting shouldn't be the problem, I was using the TopFin lighting hood that came with the setup when I got it, and that lighting wasn't that great or bright, but the staurogyne was still thriving under it. It has to be a nutrient deficiency. 

 

[jag51186]

So, if you have what is presumably a decent light, and are injecting co2, why don't you switch over to dry ferts dosed daily? EI or PPS-PRO? Both would cover all nutrients you would need.

 

[StevenF]

API leaf zone, Seachem Flourish, Seachem trace,...  Have you looked at the label to see what is in each bottle?  Each bottle should list the elements in it.  Seachem  Flourish has all of the micro elements needed and small quantities of the macro elements (potassium, nitrogen,  phosphorous).  The nitrogen fertilizer you used probably had potassium nitrate.So if you fertilize with nitrogen and Seachem Flourish the only element you could  be low on is Phosphorous.  I suggest you get a phosphorous test kit.  You want your phosphate at about 0.5ppm or less.  If it is higher than that you likely would have  algae issues.
 
 Normally feeding fish will provide all the Macro elements needed.  But in a CO2 tank with bright lighting the plants might pull the phosphate to very low levels.  However you also state you had zero nitrogen,  Without nitrogen the plant might not be able to fully use the phosphorous.  If that happened the phosphate levle may have increase to above 1ppm or more.  If it got too high your plants might stop growing.   
 
The other possibility I see is that with a CO2 system you might deplete micro elements very fast and if that happens your plants will stop growing.  If that is the case dose with Seachem Flourish more than recommended.   
 
 
 
This link lists al of the elements plants needs   
 
http/soils.wisc.edu/facstaff/barak/soilscience326/listofel.htm
 
I would strongly suggest checking your phosphates.  Then doing a large water change to reset the nutrients levels, and the fertilize with Seachem Flourish and and a potassium nitrate fertilizer (Seachem nitrogen is one I use).  Then monitor the tank and plants.  If phosphates are very low or near zero you might have to add a small amount of Phosphate or feed your fish more often. 

 

[RainboWBacoN420]

I wouldn't have stated what was on the bottle if I didn't read the label of the bottle. I don't add anything to my tanks unless I know exactly what they are. Leaf Zone doesn't list all of the facts, though. I know it's rich in potassium and iron though (kind of want to stop using API ferts, they don't seem to compare to Seachem ferts), I'm pretty much just finishing the bottle to get it out.  And yes, I've been contemplating getting a phosphate checker. I'm already dealing with algae issues. I should have gotten Seachem Nitrogen instead of the trace, now thinking about it. I was thinking it might be lacking in trace elements, if they've been depleting rapidly. All my other plants are doing great, especially my bacopa. It's just the staurogyne that's been stunted. 
But that makes sense, right? With the lack of nitrogen, they can't properly use the phosphorus, which is why I have algae issues? Am I understanding this correctly...?
 
This was very helpful, thank you. I'm kicking myself for only getting the trace and not the nitrogen, I choose to go with trace in the case that it was lacking more than just the nitrogen. 
 
Should I attempt to hold off on water changes to see if nitrates can build up? Of course, I'll monitor them carefully to make sure they don't surpass 20 ppm, or as some people recommend, even pushing it to 40 ppm. (referring to the Nitrate Debate in the Tropical Discussion category). 
 
 

So, if you have what is presumably a decent light, and are injecting co2, why don't you switch over to dry ferts dosed daily? EI or PPS-PRO? Both would cover all nutrients you would need.

I'll look into these, thank you.