Addressing stunted growth in staurogyne repens

[sunnybacon]

I've really grown fond of Staurogyne, it's become one of my go-to plants in the hobby. I love how it looks, it's been a fantastic foreground plant in my 15-gallon tank. Even before I started CO2 injection, it was doing amazingly well. It just kept growing like crazy. But then, a few months ago - I think it was around October - the leaves started deteriorating. They turned brown and got all wavy, like melted tissue paper. The stems were still healthy, but they weren't producing any new leaf growth. I thought maybe it was a nitrogen deficiency, since my nitrates were at 0. So I upgraded my lighting and fertilizers. I switched from API Leaf Zone to Seachem Flourish, but that didn't seem to help.

I didn't kill them, I just trimmed them back pretty nicely. I figured that would encourage new growth, but it's been a couple of months now and nothing's really happening. There are some tiny new leaves growing at the top, but it's not like it's thriving or anything. It seems like it's really struggling to produce new leaves and grow. Yesterday, I picked up some Seachem Trace Elements at work. I'm hoping that'll do the trick, since it's got cobalt in it, which is supposed to help with nitrogen fixation.

So, if all else fails, what else can I try to get my Staurogyne back on track? I really don't want to get rid of it, it's been in my tank since the beginning and I love it as a foreground plant. But if I have to, I'll consider replacing it with something like cardinal plants or dwarf baby tears. For now, I'm just focused on getting my Staurogyne thriving again.

Oh, and before anyone asks, here are my tank parameters:
Ammonia: 0 ppm
Nitrites: 0 ppm
Nitrates: 0 ppm
pH: 6.6
Copper: 0 ppm
GH: 70-80 ppm
KH: 70-80 ppm

Thanks for any help you can offer!

[seaquake]

"Hey, so just wondering - what's the deal with your lighting setup? You mentioned upgrading it, but didn't give any specifics. I'm curious to know, was it a major overhaul or just a tweak?"

[sunnybacon]

I'm using a Marineland LED Light Strip - it's 234 lumens, 7800K. I don't think lighting is the issue here, though. I mean, I was originally using the TopFin lighting hood that came with the tank, and it was nowhere near as bright as this one, but the staurogyne was still doing great. So, I'm pretty sure it's a nutrient thing.

[seaquake]

I'm curious, with your setup, why not consider switching to dry ferts dosed daily? You've got a good light source and CO2 injection going on. Both EI and PPS-PRO would cover all the necessary nutrients, don't you think?

[shakinStevens]

Have you taken a closer look at the labels on your fertilizers - API Leaf Zone, Seachem Flourish, and Seachem Trace? Each one should list the elements it contains. For example, Seachem Flourish has all the micro elements your plants need, plus small amounts of macro elements like potassium, nitrogen, and phosphorous. If you're fertilizing with nitrogen and Seachem Flourish, the only element you might be low on is phosphorous.

I'd recommend getting a phosphorous test kit to check your levels. Ideally, you want your phosphate levels to be around 0.5ppm or less. If they're higher, you might start to see algae issues. Normally, feeding your fish should provide enough macro elements, but in a CO2 tank with bright lighting, your plants might use up the phosphate quickly.

However, with zero nitrogen, your plants might not be able to use the phosphorous effectively, leading to higher phosphate levels. If that happens, your plants might stop growing. Another possibility is that your CO2 system is depleting micro elements quickly, causing your plants to stop growing. If that's the case, you might need to dose Seachem Flourish more frequently than recommended.

I'd suggest checking your phosphate levels, then doing a large water change to reset your nutrient levels. After that, fertilize with Seachem Flourish and a potassium nitrate fertilizer like Seachem Nitrogen. Monitor your tank and plants, and if your phosphate levels are very low or near zero, you might need to add a small amount of phosphate or feed your fish more often.

[sunnybacon]

I'm glad you pointed that out about the phosphate levels, it makes total sense now. I mean, I did read the label on the bottle, I wouldn't just add something without knowing what's in it. API Leaf Zone doesn't give you the full picture, but I do know it's got potassium and iron in it - I'm actually thinking of switching to Seachem ferts altogether, they seem way better.

I've been thinking of getting a phosphate test kit, especially since I'm dealing with algae issues. And yeah, I'm kicking myself for not getting Seachem Nitrogen instead of the trace elements - I was worried it might be lacking in those, but now I think I should've gone with the nitrogen. It's weird that all my other plants are doing great, especially my bacopa, but the staurogyne is just stunted.

So, just to make sure I understand - with low nitrogen levels, the plants can't use the phosphorus properly, which is why I'm getting algae issues, right? That makes sense. Thanks for explaining it to me, it's been really helpful.

I'm thinking of holding off on water changes for a bit to see if my nitrates can build up - I'll keep a close eye on them, of course. I don't want them to get too high, but I've heard some people recommend pushing them up to 40 ppm. What do you think?