Hygrophila polysperma with yellow leaves

[Akysten]

I've got a reletively new tank.
This is a 60 gallon with Eco complete covered with a thin layer of gravel(my wife hated the looks... but wanted plants... it's a compromise). I have about 2wpg of 6700(?) lighting.

It's not well planted right now. I have

1 Amazon Sword(medium) doing well
1 Unknown feathery plant doing well
1 some sort of Red Rotala doing well
1 Cabomba caroliniana (died, it wasn't too healthy to start)
1 Small Ludwigia repens(vert small and destroyed by Clown Loach)

1 Bunch Hygrophila polysperma, roots growing down to substrate, but leaves are yellow. Plant is NOT doing well... it's doing much better in a smaller tank with Gravel substrate and low light.

I find this interesting... I know why the Ludwigia and Cabomba died... but as I understand it, some of my more difficult plants appear to be doing well, and my "easy" plant is struggling! Hygrophila polysperma should grow almost anywhere!

What could be the reason? I've read that Iron or Nitrogen shortages could cause this, but I would expect these other plants to be affected... right?

Any ideas?

[IndianaSam]

What fertilizers are you giving the plants?

I may be remembering incorrectly, but yellowing leaves indicate a potassium deficiency.

Sam

[Akysten]

I didn't add anything until recently. I figured that new Eco Complete would be.. well... complete.

I added something(that I bought before doing reseach) called Plant Grow from Nutrafin.. I see Nitrogen and Iron... no Potasium. I didn't add the recommended ammount as I was hesitant to add too much Iron to the tank.


The STRANGEthing is that this plant is supposed to be one of the easiest to grow. The Rotala, but the Rotala, and Amazon Sword are taking off... It's just the Hygro. What's funny is that it's growing, but the leaves are Yellow... not freen with some red... like is typical, but just "yellow" no hints of red or great.

[phanmc]

If the yellowing occurs on new leaves, it's likely iron deficiency. If it's on old leaves it's nitrogen or phosphate. If it's in patches then it's probably potassium.

A possible reason why you see the problem on the hygro is that it is a very fast growing plant and nutrient hog. Since they grow faster than the other plants, they'll also exhibit problems before others.

Why does it seem to do better in a lower light tank? With less light, the plant will grow slower and will consume less nutrients. Increase the light and you'll have to increase the nutrients and CO2.

[twig]

Plant GRO by hagen provides trace elements. Those are important but you actually need macro nutrients, too.

www.gregwatson.com for the win :D

I buy the poor mans dry fert. Not because i'm poor but because mixing some chems into water and adding to the tank isn't much of an issue at all and it saves a LOT of money.

[Akysten]

Thanks... at least for now with the iron, that helps.
I think it's because I ended up "draining" my initial setup of Eco Complete a couple times... so I may have washed out a lot of the nutrients(that's $90 down the drain!)

Anyway, I've added Iron.. as a supplement to the water. I'll look up other fertiliazation options. Thanks for your help and the link.