Deficiency symptoms in H. leucocephala – magnesium or iron deficiency?

[Phil_1983]

Hello everyone,

I have a problem in my larger tank, the 240-liter aquarium. Ever since I set it up, my plants have been dying off, especially the floating plants. Limnobium laevigatum and hygroryza aristata in particular.
Today I noticed that I can clearly see the leaf veins on the floating H. leucocephala. I’m just not sure. So is this a magnesium deficiency?

In case it’s relevant: On the planted Echinodorus, new leaves—if any appear at all—are sometimes glassy.


Could it be that H. leucocephala is taking up so much of the little fertilizer available that there’s nothing left for the other plants?

pL.com (free version)

 

[MacZ]

Classic iron and nitrogen defficiency. Those kill of Limnobium first, then Hydrocotyle is affected. And yes, semiemerse plantzs like H. leucocephala or Epipremnum reduce nutrients in the water very effective, that's why they are often used to bring down EC.

What are your water parameters?

If in doubt use a makro+mikro fertilizer in low doses.

 

[Phil_1983]

Classic iron and nitrogen defficiency. Those kill of Limnobium first, then Hydrocotyle is affected. And yes, semiemerse plantzs like H. leucocephala or Epipremnum reduce nutrients in the water very effective, that's why they are often used to bring down EC.

What are your water parameters?

If in doubt use a makro+mikro fertilizer in low doses.

Okay, thanks.

Parameters:

EC: between 25 and 40 us/cm, depending on what day after wc you are measuring.
pH - drop test: around 6
No3 - I get different readings, but it is usally low. Between nothing and 1 ppm
KH - Not detectable with drop test (switches color with the first drop)
GH - I have no test
No2 - lower than 0,01 ppm (lowest measurement the test offers)

I do use Tropica specialized fert (the green one). Not much, but 4 ml every 2 days. Feels like its used up immediately.

 

[MacZ]

As suspected.

Iron and Nitrogen. Tropica Specialized is the one I use as well. Raise the dose to 3 pumps (6ml) and add more leaf litter. I was able to drop the fertilizer the more mulm and detritus accumulated until everything grew like weeds just from the nutrients from rotting plant material and fish food/waste.

 

[Phil_1983]

Ok, thanks, I will do as you say.
I was cutting a little bit short on the botanicals, because the wood is tinting the water so much, that i really are at the point of too dark water. But maybe this is just subjective

 

[MacZ]

Especially then stick to oak or beech leaves. they barely tint the water in comparison to Catappa.

 

[Phil_1983]

Okay, I didn't know that. Thanks!

 

[dw1305]

Hi all,

Could it be that H. leucocephala is taking up so much of the little fertilizer available that there’s nothing left for the other plants?

Yes, I think that is probably it. Have a look at the <"Duckweed Index">, I'm <"absurdly proud of it">, but it does work.

and hygroryza aristata in particular.

It has never lasted for me. I think it <"needs more nutrients"> than either of us offer.

Today I noticed that I can clearly see the leaf veins on the floating H. leucocephala. I’m just not sure. So is this a magnesium deficiency?

What @MacZ says, either iron (Fe) or magnesium (Mg). If it is magnesium you should get rapid greening when you add some. Magnesium sulphate heptahydrate (MgSO4.7H2O) should be obtainable as "Epsom Salts" and is ~10% Mg.

If it is iron (Fe) greening will only occur <"with new growth">.

cheers Darrel

 

[anewbie]

There are two different type of FE fertilizer - i forget what they are but one does not work well in acidic water so you want the other type

 

[Phil_1983]

Hi all,

Yes, I think that is probably it. Have a look at the <"Duckweed Index">, I'm <"absurdly proud of it">, but it does work.

It has never lasted for me. I think it <"needs more nutrients"> than either of us offer.

What @MacZ says, either iron (Fe) or magnesium (Mg). If it is magnesium you should get rapid greening when you add some. Magnesium sulphate heptahydrate (MgSO4.7H2O) should be obtainable as "Epsom Salts" and is ~10% Mg.

If it is iron (Fe) greening will only occur <"with new growth">.

cheers Darrel

Okay, thanks. In fact, I already worked through the duckweed index, but I guess I am still too blind to identify the causes . The "melting" of the limnobium did really confuse me.

Too bad, I really like the h. aristata. Especially the roots.

Would you go for trying to raise Mg first and then see if it works?

 

[Phil_1983]

There are two different type of FE fertilizer - i forget what they are but one does not work well in acidic water so you want the other type

Yes, I know. I was thinking that I have the right one, because it works pretty well in the other tank.

 

[dw1305]

Hi all,

... Would you go for trying to raise Mg first and then see if it works?

Yes, that is definitely where I would start.

Cheers Darrel

 

[Phil_1983]

Perfect. Thank you.

 

[dw1305]

Hi all,

Perfect. Thank you.

It should perk up fairly quickly if magnesium (Mg) is Liebig's limiting nutrient.

Cheers Darrel

 

[Phil_1983]

Good to know. I just added a small amount.