# Request for help with deficiency identification



## kaegunim (Jan 15, 2010)

I have not had my planted tank long, but my Hygrophila polysperma is starting to get some holes in the lower leaves of the tallest (and most actively growing) stalk.

I originally thought this might be the work of my infestation of pond snails that came with the hygro, but it seems concentrated on these few leaves, and the snails that I catch can be found all over, especially preferring to hang out in the hygro difformis, which is not affected by this spotting.

This is a 20 gallon tank, originally lit with a single 18 inch t8 (f15). I have just recently added an additional fixture (read ghetto desk lamp) now lit with 3 18 inch t8 tubes (for a total of 45W), along with a newly installed yeasty carbon dioxide setup that seems to be running stably at 0.2 bubbles per sec.

As yet totally unfertilezed, though London's ridiculously hard water is pretty good for trace elements.

On this note, I will put out the thought that it might still be iron defficiency, as this particular plant has started reddening prettily as it has gotten closer to the surface, perhaps depleting the iron reserves of the lower portions?

Here is a photo of the afflicted area. Once again this is pretty much the only affected region of any plant in the tank.










Thanks


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## Darkblade48 (Jan 28, 2008)

To me, it looks more like algae than holes in the leaves...

For the leaves that definitely have holes (the yellowing leaves), it could be due to a lack of light (i.e the top portions are shading out the bottom portions), or it might just be because the leaves are getting old and the plant is shedding them.


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## Calmer (Mar 9, 2008)

Are you fertilizing the plants yet? It's probably a potassium deficiency. 
http://www.theplantedtank.co.uk/deficiencies.htm


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## Chris S (Dec 19, 2007)

Lack of potassium is a good diagnosis. Since you aren't dosing macro's, it could be a combination of nitrogen, phophorus and potassium though. Lack of nitrogen can also sometimes explain a slight reddening of the leaves.


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## kaegunim (Jan 15, 2010)

Thanks Calmer,

That is a very useful reference.

Woe the need to fertilize. If only I had listened when told that the aquarium hobby is a terrible money-sink! ^o^ Oh well, it is an attractive money sink at least~

Unfortunately we only have K2HPO4 on hand... So I will have to fork over for some KNO3 and K2SO4 T_T

Ohh well. 

Heavy metals are just trace dosing and there should be enough in tap water, yes?

Thanks


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## Calmer (Mar 9, 2008)

Your welcome kaegunim  That is one of my favourite websites.

Trace elements are in our water and it comes from runoff. If you now have light, co2 and NPK the next thing you may need is more trace to balance it all out. Water changes also alters the balance. Some people achieve the balance with the Estimative Index method. Some with PPS-pro method. And others with trial and error.


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