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Help requested identifying possible nutrient deficiency . . .

Wookii

Member
Joined
13 Nov 2019
Messages
4,283
Location
Nottingham
I am currently having issues with with a couple of plants. The first being Hygrophila polysperma sunset (Indian water weed). It grows rapidly - in fact it’s the fastest growing plant in my tank, but it’s getting lots of white on new leaves. I know it is a plant that does have white veins naturally, but this doesn’t look quite right on some leaves. Some older leaves are also showing some areas of thin/open patches (see leaf on top left of image):

upload_2020-2-23_15-56-32.jpeg


I’m also have very slow growth on my Cardamine lyrata, which used to grow really well, with thinning of the leaves and yellowing. I wondered if this is due to lack of light, as it is heavily shadowed by hardscape and moss.

upload_2020-2-23_16-16-36.jpeg


Other plants like crypts, mosses, grow really well without an issue. I am also getting reasonable growth with Ludwigia Palestrina and Myriophyllum guyana, though not as strongly as the weeks following initial planting.

I am EI dosing (micros/macros alternate days), using an auto-doser (so on a 14 day cycle without rest days) but also doing daily 25% trickle water changes via an auto-water change/overflow system.

I’m happy my CO2 is on point, and flow and distribution around the tank is good.

So does these issues look like a nutrient deficiency or not?

I live in a hard water area (Nottingham) and have GH if around 13dH and KH around 6dH, so I did wonder if iron was an issue so I’ve been manually dosing 1ml of TNC Iron (DTPA) daily for the last two weeks, which has not improved these two plants (though other plants do look a little greener.

I may need to up the EI dosing to account for the daily water changes, though I wouldn’t have thought any of the macros were running out even so?

Can anyone make any suggestions?
 

Thanks, I have read that one already, and a couple of others on EDDHA Fe whilst researching if this could be an iron issue. As I say above, I am dosing DTPA iron daily in addition to the EDTA iron that is in the standard APFUK micro mix, as a result of reading threads like that. Plus my aquarium pH never goes much above 7.1, is below 7.0 for around 20-22 hours per day, and is around pH 6.2 during the entire photo period (dosing occurs just before lights on). So in theory I should be well covered on the iron front, no?

Are you saying the images I have posted above are definitely an iron deficiency?
 
I mixed in DTPA powder into my APF micro mix and it seems to do the job i have a similar ph to you for most of the day. I have been running into a little iron deficiency so i've increased the dose so hopefully i'll see an improvement in a week or two.

How much iron are you adding/targeting assuming the EDTA isn't available/working?
 
I mixed in DTPA powder into my APF micro mix and it seems to do the job i have a similar ph to you for most of the day.

How much iron are you adding/targeting assuming the EDTA isn't available/working?

Well, I've been adding 1.2ml daily of the TNC Iron AT (which is pre-mixed DTPA) which should give me 0.2ppm of DTPA iron on top of the EDTA in the micro mix.

I know test kits are frowned upon on this forum, and Darrel will chastise me shortly, but my JBL iron test kit does result in a non-zero colour 48 hours after a micro dose (i.e. half an hour before the next micro dose), suggesting there is still 'some' available iron in the water column - and that is with just the standard mirco mix dose, so the DTPA should result in even more still available on top of that (?)

That said, I've been told to ignore test kits, and rely on the plants, which is what I'm trying to do in starting this thread.
 
I've used the TNC iron before, but just added it into my APF mix as i use a auto doser. It seemed to work for me. I would suggest to dose it 3x a week on micro days, maybe 0.3 per dose and wait two weeks. I would also bump up the macro dose by 10-20% too just to make sure you are not running low on NPK (mainly N&K).
 
I've used the TNC iron before, but just added it into my APF mix as i use a auto doser. It seemed to work for me. I would suggest to dose it 3x a week on micro days, maybe 0.3 per dose and wait two weeks. I would also bump up the macro dose by 10% too.

Thanks, yes I decided to add it to my micro mix last night after doing it manually for two weeks (I'm using an auto-doser too). Incidentally where did you get your powdered DTPA Fe from?

I actually increased my micro and macro doses last night also. I worked out that my daily 25% water change would result in average EI levels being about 40% below standard (compared to a usual 50% weekly water change), so I've increased dosing from 12ml to 20ml. That could end up being the root of the issue in any case, though to be fair 60% of EI should still be enough for my aquarium which is predominantly slower growing plants!
 
Hi all,
The first being Hygrophila polysperma sunset (Indian water weed). It grows rapidly - in fact it’s the fastest growing plant in my tank, but it’s getting lots of white on new leaves.
so I did wonder if iron was an issue so I’ve been manually dosing 1ml of TNC Iron (DTPA) daily for the last two weeks, which has not improved these two plants
So does these issues look like a nutrient deficiency or not?
Are you saying the images I have posted above are definitely an iron deficiency?
It looks like iron (Fe). The chlorosis is in the new leaves, which makes it a problem with a non-motile element and these are boron (B), calcium (Ca), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), so you don't need a lot of any of them (they are micro-elements), and plants need very small amounts of boron, zinc, copper and manganese.

So the two options are really iron (Fe) and <"manganese (Mn)">, and iron is the most likely. It will take a while for the new leaves to grow green, and the old leaves will always be white (<"or spectacularly banded">).

cheers Darrel
 
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Hey @Wookii I'd personally say that it WAS an Iron deficiency, smallest leaves on the left look green again - I'd simply keep the Fe on your new level and observe the plants (and very possibly it was N deficiency as well as both Fe/N deficiencies often walk together - no Fe = problems with N uptake and as @dw1305 mentioned, leaves will stay white/very bright).
 
Thanks, yes I decided to add it to my micro mix last night after doing it manually for two weeks (I'm using an auto-doser too). Incidentally where did you get your powdered DTPA Fe from?

I actually increased my micro and macro doses last night also. I worked out that my daily 25% water change would result in average EI levels being about 40% below standard (compared to a usual 50% weekly water change), so I've increased dosing from 12ml to 20ml. That could end up being the root of the issue in any case, though to be fair 60% of EI should still be enough for my aquarium which is predominantly slower growing plants!

I've been buying my salts from aqua plant care:
https://aquaplantscare.uk/shop/aquatic-plants-fertiliser/organic-iron-fe-8-dtpa-chelated/
 
Hi all, It looks like iron (Fe). The chlorosis is in the new leaves, which makes it a problem with a non-motile element and these are boron (B), calcium (Ca), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), so you don't need a lot of any of them (they are micro-elements), and plants need very small amounts of boron, zinc, copper and manganese.

So the two options are really iron (Fe) and <"manganese (Mn)">, and iron is the most likely.

cheers Darrel

Thanks Darrel. Would you say this is also the same issue with the holes and yellowing in the Cardamine lyrata (I know its a crap zoomed in image)?

After doing some external reading I did wonder if Manganese could be a candidate also, given the holes/thin patches - I also have virtually none in my tap water (per Severn Trent's water report for my area). Does an EDTA chelated version suffer the same precipitation in hard water as Fe?

I've seen (I think) you recommend this Chempak Sequested Iron before, which I think is a DTPA Iron (?) and also contains Manganese - would the Manganese also be DTPA chelated?
 
Thanks Darrel. Would you say this is also the same issue with the holes and yellowing in the Cardamine lyrata (I know its a crap zoomed in image)?

After doing some external reading I did wonder if Manganese could be a candidate also, given the holes/thin patches - I also have virtually none in my tap water (per Severn Trent's water report for my area). Does an EDTA chelated version suffer the same precipitation in hard water as Fe?

I've seen (I think) you recommend this Chempak Sequested Iron before, which I think is a DTPA Iron (?) and also contains Manganese - would the Manganese also be DTPA chelated?

From what I've read all the other chelated traces break down at much higher PH that we don't need to worry about. It's iron that's breaks down at lower PH (dependant on chelate used).
 
Hey @Wookii I'd personally say that it WAS an Iron deficiency, smallest leaves on the left look green again - I'd simply keep the Fe on your new level and observe the plants (and very possibly it was N deficiency as well as both Fe/N deficiencies often walk together - no Fe = problems with N uptake and as @dw1305 mentioned, leaves will stay white/very bright).

Thanks Witcher - I'll stick with the increased Fe - I assume there is no downside to higher levels of Fe in any case? I was going to mention that some of the new growth doesn't seem affected.

Will the whiter leaves recover, or should these be removed?

What are your thoughts on the holes in the Cardamine lyrata - lack of light, or all coming back to the Fe issue?
 
From what I've read all the other chelated traces break down at much higher PH that we don't need to worry about. It's iron that's breaks down at lower PH (dependant on chelate used).

Thanks Sammy, that's good to know.
 
Hi all,
Will the whiter leaves recover, or should these be removed?
I was going to mention that some of the new growth doesn't seem affected.
It is only the new growth that will be greener, it is back to @Zeus.'s "future of aquascaping" picture.
I have been dosing Fe DTPA in my custom trace mix and with it being light sensitive I've also been dosing Fe EDDHA manually, so the plan is to dose the Fe EDDHA only via one auto doser and dose the trace mix without the Fe DTPA. Im dosing the Fe EDDHA so the water keeps a very light pink tinge to the water and I will be watching my Pogostemon helferi as it does seem very Fe sensitive in my tank see pic below as I've played around with different Fe ppm doses
upload_2019-12-15_18-4-29-png.png
I've seen (I think) you recommend this Chempak Sequested Iron before, which I think is a DTPA Iron (?) and also contains Manganese - would the Manganese also be DTPA chelated?
I'm not actually sure. You can get 13% Mn chelate, so it may well be.

cheers Darrel
 
Thanks Witcher - I'll stick with the increased Fe - I assume there is no downside to higher levels of Fe in any case? I was going to mention that some of the new growth doesn't seem affected.

Will the whiter leaves recover, or should these be removed?

What are your thoughts on the holes in the Cardamine lyrata - lack of light, or all coming back to the Fe issue?

I think there is no downside to higher levels, however I've never kept more than 0.8ppm of Fe (calculated, but not tested). Only thing I may think of is the increased hunger for NO3. White leaves will most probably melt.

If C. lyrata is also getting slightly yellowish, my guess would be lack of NO3, I have this plant as well but it seems to be fussy with my fert regime, some of the bottom leaves are quite often covered by algae and have holes similar to yours but coming from the edges of the leaves (and top parts look absolutely perfect). I occasionally simply remove affected parts or replant tops, it's a fast grower so within 2 weeks everything looks perfect again and... the problem restarts. I think it's impossible to have every single plant in my tank looking absolutely perfect, so I concentrate on the more problematic ones and simply re-plant fast growing ones - lots of plants we keep in aquariums have so different needs from each other, that we won't be able to keep all of them absolutely happy.
 
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