Amazon sword leaf tip problem.

Has anyone experienced a problem with amazon sword leaf tips turning brown? I've a 5" deep gravel substrate where I add 2 tnc complete root tabs to each sword every 8 weeks. The plant growth is excellent all leafs are a good strong green. I have lots of other plants in my 55gallon aquarium, they're all doin well. Water parameters are ammonia 0
Nitrite 0, Nitrate 5, ph7, phosphate 2ppm.I also use tnc complete 10ml 3x aweek ,liquid potassium 10ml 3x a week ,liquid iron 5ml 3x per week. When I lightly rub the brown sword leaf tips the leaf tip becomes transparent. My light is a fluval plant 3.0 which runs at 9 hours but only runs at 100% power for 3 hours out of the 9 hours.An I run co2 for 8 hours

 

I don't think I've dealt with this, but I'd be curious to see some pictures if you have any. Pictures, along with the information you've given, may help people better identify what is going on.

 

Here's a photo as requested

 

Looking at your photo, I'm wondering if the brown tips might be the result of some sort of algae. I don't know why algae would prefer just that one spot, but it looks like diatoms to me.

 

Looking at your photo, I'm wondering if the brown tips might be the result of some sort of algae. I don't know why algae would prefer just that one spot, but it looks like diatoms to me.

Yea its got me stumped everything else is pristine. I could understand if my phosphates were really high or my nitrates were high. Could it be to much light or not enough???

 

Can you post a photo of your app light period ?

it’s a strong light and I wonder if the lights are frying the tips as they are closest to the surface. I had to turn mine down so much as it was literally burning leaves. Happy to share what mine is set to if you’re interested at all.

 

Yea its got me stumped everything else is pristine. I could understand if my phosphates were really high or my nitrates were high. Could it be to much light or not enough???

In my experience, if it's diatoms, higher light can make them go away. Doing this seems to trade diatoms for green dust algae though...so I don't know if that's an improvement in your eyes.

 

In my experience, if it's diatoms, higher light can make them go away. Doing this seems to trade diatoms for green dust algae though...so I don't know if that's an improvement in your eyes.

I've added 4 oto's to see if they can combat the problem. I don't fancy the idea of increasing the light, it currently runs at 9 hrs now with a 3hr peak at 100%.

 

If it is a supplement issue potassium, and iron supplements would help. I use Seachem.

 

If it is a supplement issue potassium, and iron supplements would help. I use Seachem.

I use both of those supplements seachem potassium and tnc liquid iron.

 

I've added 4 oto's to see if they can combat the problem. I don't fancy the idea of increasing the light, it currently runs at 9 hrs now with a 3hr peak at 100%.

That makes sense to me. I hope the otos prove to be helpful. If not, at least you can rule out the diatom hypothesis. Good luck.