Amazon sword turning brown

[lpn4]

Hi all. I recently purchased an Amazon Sword plant, that already had a few babies growing. Only one baby had a root system. My problem is that since planting, the outermost leaves had turned brown, with a few darker spots. The innermost new growth seems glassy and clear. My tank parameters are as follows:
55g cube; 2x6000kT5
Ammonia: 0
Nitrite: 0
Nitrate:<.25
PH: 7.6
Phosphates: .5 (I have a phosphate remover pad, since my tank is not able to control phosphates on it's own).
Temp: 79
The tank was cycled nicely over a 2 month time frame.
I have researched this subject, and found many answers, but cannot decide which way to go. Is this natural die-off? Are there diatoms on my plants? Do I need Potassium? Should I have used half a fert tab under it instead of a whole one? Any advice from past experience would be great. Thank you in advance.

 

[aqua_chem]

Double check your nitrates, they usually aren't that low. Make sure you're shaking the bottles really well.

Apart from that, if your nitrates are almost nonexistant and you're using a phosphate pad, of course you are going to be seeing severe deficiencies.

 

[paytertot]

My Amazon sword looked like it was dying at first but it was just because it was grown emersed and had to regrow leaves adapted for submersed growth. Maybe that's what's happening?

 

[jetajockey]

I'd look into root tabs also.

 

[aqua_chem]

The deformation of the new growth suggests that something else is hampering growth.

 

[aqua_chem]

I'd look into root tabs also.

I think he already has them.

 

[jetajockey]

Doh, I missed the last sentence in the thread. Genius at work =s. What kind of root tabs? Most are not very comprehensive.

How long has this been planted? I have gotten swords with runners like that, and since they have runners in that fashion it looks like it probably wasn't emersed. That combined with new growth being clear-ish or small would say to me that you are having nutrient deficiencies. So in shot, aqua nailed it I think =s.

 

[lpn4]

Yes, I do have root tabs. My nitrates are somewhere between 0 and 5.0. I always shake it for longer than the instructions say. Should I take out the Phosphate pad? Do my plants need phospate? Should I try CO2? I have read that Amazon swords can thrive without it.

 

[lpn4]

I am using FlourshTabs by Seachem. I planted the sword about a month ago.

 

[aqua_chem]

I would remove the pad if you don't have a immediate need for it. Also, why is your nitrate so low? Are you only lightly stocked, or do you have a lot of other fast growing plants?

Swords are fine without co2. Co2 will help your plants immensely, but is ultimately optional.

 

[lpn4]

I have a 55g with only roughly 22 inches of fish. I have a couple of aquatic ferns growing, and their bottom leaves are brown as well, though the rest of the plant, including new growth, looks great. As far as the phosphates go, I thought high phosphates could cause algae growth, and I only placed the pad in about a week ago, after the browning began. My phosphate levels are usually >1.