[kekon]

Some time ago i purchased some specimens of this plant and put it into my tank. Unfortunately it didn't grow at all. I watched it dying day by day. It lost its rich red color, the tips got dwarfed. Being aware of too high NO3 levels and too low K that cause stunting i dosed little NO3 and much K. Also, Ca and Mg were under control. It was all in vein, the plant looked ugly. Because i use only RO water i know what amounts of nutrients are added into the tank. The micro fert i used had the same amount of boron and zinc. I decided to double boron content and started to dose. (now, it's 0.008 ppm Zn and 0.015 ppm B weekly)
Within a week Macrandra "woke up" and started to grow ! Now it grows very fast and have rich red colors. Then i set boron and zinc dose to 1:1 ration. The plant still grew but not as fast as before. I set B:Zn to 2:1 again and the plant began to grow fast again. So, it seems that the cause of bad healh of this plant was too little boron. However, one has to be very careful when adding more boron - this nutrient is very easy to overdose and become toxic to other plants !

 

[BryceM]

Kekon,

It's good to see you. R. macranda is certainly a demanding plant. Your observations about boron are interesting. Most of us in the hobby just assume that our particular micro mix will supply the correct amount of all of the traces. It's probably good to be reminded that not all assumptions are always accurate.

 

[Bert H]

Great observation, Kekon. Do you add this via boric acid?

 

[kekon]

Yes, i use only boric acid as a source of boron. When i was watching different tap-water contents reports i found there were different concentrations of boron - from 0.008 ppm to 0.1 ppm.

 

[Avalon]

Interesting observation. I'm a little hesitant to say it's Boron since there are so many other factors that it could be. I keep this plant in RO water and find it very easy to grow. My only source of B & Zn is Tropica's Plant Nutrition Liquid. Interestingly, it has exactly a 2:1 (B:Zn) ratio. Hmmm...

 

[BryceM]

I grow it under MH lighting in reconstituted RO water with Tropica's micros too. Same result as Avalon - it grows pretty well. At times, it even becomes a nuisance.

 

[suaojan]

My experience with Rotala Macrandra is that it needs a large amount of light and CO2. In good conditions, you'll see lots of pearls under the leaves of R. Macrandra.

 

[HeyPK]

Of all the micronutrients, except possibly iron, boron deficiency has occurred the most frequently for me. I have seen it when I was in Massachusetts, Wisconsin, and, now, central Mississippi. Boron deficiency is always a possibility when one gets stunted tips and/or roots. Calcium and iron should also be considered. I don't think I have ever seen zinc deficiency. Perhaps my regular micronutrient dose takes care of zinc needs.

 

[Bert H]

Kekon, with the toxicity of Boron being what it is, exactly how much would you add to a given volume of water? How much of a margin of error is there with this element?

This topic has come up in the past. A while ago I bought a bottle of boric acid, but never did use it, so I am curious. Thanks.

 

[HeyPK]

Burt, What is the concentration of the boric acid? I made up some 0.1molar boric acid (6.2g/L) and I add 1 ml of that per gallon of tank water. This cures boron deficiency for a very long time, and I have not seen any toxicity symptoms.

 

[Edward]

..... 1997, CSM+B ..... (B as Boron)

 

[Bert H]

Burt, What is the concentration of the boric acid? I made up some 0.1molar boric acid (6.2g/L) and I add 1 ml of that per gallon of tank water. This cures boron deficiency for a very long time, and I have not seen any toxicity symptoms.

It's powder, so I could make the 0.1M solution accordingly also. Do you add this with weekly water changes?

 

[HeyPK]

I would add 1 cc of this mix for every gallon of new water put into the tank. If you don't change water frequently, this level of boron lasts a long time, somewhere around 4 - 6 months.

 

[Bert H]

Thanks Paul. I will give this a try.

 

[Zapins]

Hmm, time to dredge this old thread up

I think I am also experiencing boron deficiency in my R. Mac. The leaf edges are neatly curled, the plant tip is stunted as in N deficiency (which is definitely not the problem), the stem is VERY brittle and the whole plant looks dark. I think this is boron deficiency! I have never before had this deficiency, so bizarre! I'll grab some new trace ferts and see if it fixes the problem.

Boron deficiency:
In plants with poor boron mobility, boron deficiency results in necrosis of meristematic tissues in the growing region, leading to loss of apical dominance and the development of a rosette condition. These deficiency symptoms are similar to those caused by calcium deficiency. In plants in which boron is readily transported in the phloem, the deficiency symptoms localize in the mature tissues, similar to those of nitrogen and potassium. Both the pith and the epidermis of stems may be affected, often resulting in hollow or roughened stems along with necrotic spots on the fruit. The leaf blades develop a pronounced crinkling and there is a darkening and crackling of the petioles often with exudation of syrupy material from the leaf blade. The leaves are unusually brittle and tend to break easily. Also, there is often a wilting of the younger leaves even under an adequate water supply, pointing to a disruption of water transport caused by boron deficiency.

From: http://4e.plantphys.net/article.php?ch=t&id=289

 

[kekon]

I experienced boron and zinc deficiency when using TMG and RO water. Zinc deficiency appeared on Aromatica and boron just on Macrandra. It happened several times.
Usually adding 0.02 ppm of B and Zn solved the problem within a week.

 

[Zapins]

Are there any easy places to get boron? Can I buy it from a pharmacy or some other shop or will I have to get it online?

I have been using a very old batch of CSM+B which I suspect either never had enough boron or did when I first bought it and then the boron has become unavailable to plants. I am not sure if boron fouls with time like iron does when exposed to light. I think I never got boron problems before since my old house must have had enough boron in the well water. My new house however... doesn't seem to have a good amount.

 

[ashappard]

I experienced boron and zinc deficiency when using TMG and RO water.

hmm. never experienced that. Did you try increasing the dose of TMG? Is your GH good?
my macrandras do fine, 100% RODI and TMG for traces. I add ca/mg in proper ratio to get 4GH after water change.

 

[AEWHistory]

Anyone consider a Potassium deficiency? I could be wrong, but it sounds like this might fit if I'm not mixing up the signals....

 

[Zapins]

Yep, not K deficiency for me. Dosed with KNO3, KH2PO4 and K2SO4. Also dosed CaCl and MgSO4. I just need to find out where to get boron from now.

By the way, is boric acid powder ok to use? I see on ebay it is being sold as an insect/bug killer. Would this be ok to put in the tank or is there some other place that I should look for the correct stuff?