Fe, Mg or other deficiency? (with pictures)

[Iceagezzo]

Hi All,

I have a possible Fe or Mg deficiency in my tank, and I kindly ask for your help to identify which one is it:

Aquarium specs:
- 90x40x45 (160l);
- daily dosage NPKMg: 1/0,2/1,5/0,4 (Tap water ~10ppm No3); EL Profito 5ml (0,1 Fe); EL Ferro 2,5 ml (0,2 Fe);
- Presurized CO2 (~1 point of PH drop);
- 10x aquarium capacity filter turnover (spraybar - pointing forward);
- 150w Hqi for 5 hours (2,5h x twice per day);
- WC 1 x 50% per week.
If you need more info, please just ask.





Thank you,

 

[Iain Sutherland]

images havent attached

 

[Iceagezzo]

OK, changed the upload hosting site! Hope you can see them now.

 

[REDSTEVEO]

At first glance I would say both, Fe and Mg and probably NPK depending on how much lighting you have and how long it is on for. The amount of growth looks very good, it is just the lightness in the colour of the greens.

Cheers Steve

 

[dw1305]

Hi all,
Try adding a bit more KNO3, like Steve says it looks like N or K deficiency, even if your tap water normally has NO3 in it, it will have very little at the moment.

If your tap water is very hard it may be calcium interfering with the uptake of both Fe and Mg.

I might try lifting the lamp a bit higher as well, or adding some floaters.

cheers Darrel

 

[Iceagezzo]

If your tap water is very hard it may be calcium interfering with the uptake of both Fe and Mg.

cheers Darrel

If that's the case, upping Fe and Mg dosage will help (?), or despite the increased values, the interfering will continue and i'll see no improvement? Or worse, because of high Fe and Mg levels, other element uptake issue will occur?

tkx!

 

[Christos Ioannou]

But 150w over 160L? Isn't that too much?

 

[ian_m]

160litres -> 42US gallons. Which gives 150/42 -> 3.6W/gallon, original high tech research was done with US gallons. Which makes the tank very high light (probably very very very high light as using HQI), thus unless CO2 and distribution is 110% spot on, you will be death ray zapping your plants with extreme amounts of light and bleaching/killing the plants especially as they get nearer the light. You need to reduce you light levels (dimmer ?), certainly raise the light in order to reduce the levels. The plants lower down, in less light, look fine so possibly nothing to do with lack of ferts.

Also why two lots of 2.5 hours ? Giving the plants a rest ???? (old wives tale). Just one lighting period is fine.

 

[Iceagezzo]

But 150w over 160L? Isn't that too much?

Yes, the wattage seems to be high, but i play with this lamp for a long time, and i have total control on intensity by upping or lowering the fixture.

Also why two lots of 2.5 hours ? Giving the plants a rest ???? (old wives tale). Just one lighting period is fine.

I've tried lots of different schedules and this seems to work best for the plant growth of my tank and little to no algae development.
I use this program for two months now and the overal tank health improved (I was dealing with brown algae - not diatoms, rather a kind of GSA).
And yes, the divided period is because I think that my plants could develop sunburns and tissue damage if both photoperiod and intensity are high and i try by all means to reduce that issue.
The other method I used, was to rise the fixture and lower the intensity, but the plants growth was very poor, and the front lawn melted

Thx!

 

[dw1305]

Hi all,

If that's the case, upping Fe and Mg dosage will help (?), or despite the increased values, the interfering will continue and i'll see no improvement? Or worse, because of high Fe and Mg levels, other element uptake issue will occur?

Upping magnesium levels may help, but if you add Mg already you probably don't have a problem.

Iron is a slightly different argument, in that case you would need to find a chelator that is designed for higher pH levels. Have a look at <"Chelated Fe">.

I'd definitely look at nitrogen and light first.

cheers Darrel

 

[Sacha]

Split photoperiod is never a good thing.

http://ukaps.org/forum/threads/ei-calculators.26669/#post-277421

Please carefully read this article about Rubisco. after reading it you will understand why you shouldn't have a split photoperiod.

 

[Sacha]

Here, I've even copied the relevant chunk here for you.


The central role of RuBisCO in the process of photosynthesis means that it must be tightly regulated, to ensure that it is active only where and when it should be. One important layer of this regulation is the activation of RuBisCO at the beginning of the day. During the night, the RuBisCO active sites are blocked by inhibitors. So, at the beginning of the photoperiod, the plant then has to re-activate the binding sites by removing the inhibitors from the CO2 binding sites. This means that there is another set of proteins which are sensitive to light. There are additional regulators to ensure that RuBisCO only operates at daytime. Magnesium typically increases as the chlorophyl molecules become active so the sensors monitor the movement of Mg++. So here is a third limitation:
3. Activation of the enzyme is very slow at the beginning of the photoperiod. The RuBisCO in algae is more efficient because algae have a mechanism which concentrates CO2 and holds it, so they respond very quickly to the daylight. This is why siestas are a very bad idea.

 

[Iceagezzo]

Thank you for pointing that article, it is very interesting.
Reading a few more articles about Rubisco enzyme, and preffering to fully understand it before guiding after it's principles, i came up with a few questions:

The central role of RuBisCO in the process of photosynthesis means that it must be tightly regulated, to ensure that it is active only where and when it should be. One important layer of this regulation is the activation of RuBisCO at the beginning of the day.

Once activated, it stays active for the rest of the day? If so, isn't more prepared to face the second part of the photoperiod, rather than in the morning when all processes are slower?

3. Activation of the enzyme is very slow at the beginning of the photoperiod. The RuBisCO in algae is more efficient because algae have a mechanism which concentrates CO2 and holds it, so they respond very quickly to the daylight. This is why siestas are a very bad idea.

Could that also mean that the intensity at the beginning of the photoperiod, is more important rather than siesta?

I've read that Rubisco enzyme is more or less influenced by temperature and CO2, but adapts to the new conditions. Coud it adapt to different light regime, also?

Thanks!

 

[mrtjur]

While it could be because of too much light it could also be caused by nutrient deficiencies. It doesn't strike me as iron deficiency even though the stratification is right. I would rule out Mg as Mg is mobile within the plant and deficiencies thus show up in the lower, light exposed leaves. My guess is either sulphur as the signs of sulphur deficiency shows up in the upper leaves and resembles a lighter version of N deficiency. Also you don't fertilize with any sulphur so if your tap water is low on that your plants might not get enough. It could also be because of either molybdenum which also resembles N deficiency but in upper leaves but also zink which actually also fits. Zink deficincies usually result in upper leaves becoming chlorotic and light sensitive. The internodes might shorten and the plant can exhibit the "little leaf syndrome"

 

[dw1305]

Hi all

My guess is either sulphur as the signs of sulphur deficiency shows up in the upper leaves and resembles a lighter version of N deficiency. Also you don't fertilize with any sulphur

I'd be surprised if the magnesium source wasn't "Epsom salts" (MgSO4.7H2O), so also a sulphur source.

It could also be because of either molybdenum which also resembles N deficiency but in upper leaves but also zink which actually also fits. Zink deficincies usually result in upper leaves becoming chlorotic and light sensitive. The internodes might shorten and the plant can exhibit the "little leaf syndrome"

Micro-nutrient deficiencies are always hard to diagnose, but they are what they say, nutrients required in very small amounts. My suspicion would be that there are actually very few cases of any micro-nutrient being deficient, including iron (Fe).

cheers Darrel

 

[mrtjur]

Hi allI'd be surprised if the magnesium source wasn't "Epsom salts" (MgSO4.7H2O), so also a sulphur source. Micro-nutrient deficiencies are always hard to diagnose, but they are what they say, nutrients required in very small amounts. My suspicion would be that there are actually very few cases of any micro-nutrient being deficient, including iron (Fe).

cheers Darrel

I agree. I would start by added more sulphur either as epsom salts or K2SO4 depending on the total hardness of the water