Is there a nutrient deficiency?

This is the most popular TBR form, so i thought i would post this here.

Look at picture 42 in this Slideshow of my 120g. This "dwarf rubin" struggled for 12 months until i gave it targetted dosing with a Jobes stick. Four months later, it still does not like right to me.

Do the older leaves of the "dwarf rubin" look like they are showing a nutrient deficiency? For the past 6-weeks (prior to pic 42) i upped the dosing of this 120gallon tank ...so it has now been getting weekly KNO3 and KH2PO4 of 3.5tsp and 1.5t. (previously 1/2 as much), following 50% water change. The tank was first set up Nov 2008. The plant was added that month.

The week before the pic 42, i started daily dosing, dividing weekly total by 7. I also have been adding 1/12t of 10% FeDPTA and 15ml TMG per day. Hardness is realitively low. I add 1t hydrated CaSO4 and 1/3t Epsom weekly. There are more details on APC, but i know "some" people no longer visit that site. For those clandestine viewers, you can look at Details on APC. For others, you can get a good history from the PhotoBucket slide show.

 

Thanks for the answers. Lets use this post as a learning opportunity. CO2 and light are good ideas. I should try them one at a time. BTW, the "dwarf rubin" is actualy Echinodorus "Rubin Narrow Leaf" WP993 as listed in Oriental Aquarium's handbook. I am not sure what is its expected height.

CO2. Redirecting the CO2 is not easy. I didnt mention here that it is delivered as a mist using needle wheel (it may have been noticeable in several of the pictures). Clearly, the levels would be highest near the filter return, and perhaps the mist is not reaching this plant which is quite far from the inlets. I have some Glutaraldehyde on hand, so what about supplementing Carbon with that?

Lighting. Now that i have upped the nutrient levels, i probably could afford to also increase lighting. Lighting on that plant is likely inadequate. First, there is the depth, but second is the shadow of the protusion of the wood, and the overhanging plants. I think lighting is also limiting the parva. The Tek Light uses two T5s for 11 hours and all 4 for only 7 hours.

GH. I will have to think about changing GH. Clearly it is low, and may be a limiting factor for the single Echinodorus in this tank. I can probably afford to increase Ca and Mg levels some. For a long time i was only depending on water changes. My tap water has 10 ppm Ca. When i tested for GH, Ca and Mg recently i found 40ppm Ca and Mg=20ppm hardness. I have since upped gypsum dosing to increase the Ca:Mg ratio.

Mobile Nutrient Deficiency. Outer leaf deficiencies are caused by mobile nutrients. We ruled out NPK, Mg, but according to this Deficiency Table, other mobile nutrients include Zn and Mo. The symptom for Zn deficiency jumps out: "Yellowish areas between nerves, Starting at leaf tip and edges." Here is a picture of Zinc deficiency . Keep in mind that i had been using TMG at half strength.... for the past month increased to 50ml per week, and more recently supplemented with FeDPTA. I have more recently switched to CSM+B and also added another Jobes Stick for localized fertilization. I am not sure if these ferts are high or low in Zn.

KH. What about carbonate hardness. the tap water is soft, KH of 1-2. Amazonia is supposed to make it softer, but the substrate is now almost 1 1/2 years old. Still, Echindorous are carbonate users, and with low CO3=, the plant can't take advantage of another carbon source.

I am now wondering about Zinc and possibly CO3= issues. I remember that i had problems in another Amazonia tank with a red horemanni. It took that plant a year to recover, and it is still short compared to how large it was in other substrates in the past. However, it doesnt show the inter-vein yellowing. See Horemanni issues.

 

regarding light and carbon -- why would that only affect the older leaves?

with 2.5% Glut that would be 36ml. I have most of a gallon doing nothing. It wont be hard to do this for a couple weeks to see what happens. How long before the plant responds. The plant only seems to retain 2-3 nice leaves. I could also tweak the bubble count. The pH is currently around 6.8 and my other tanks are 6.6 (measured in sump, and with a probe that hasnt been calibrated in 6mos. . But from a relative standpoint, certainly less CO2 than the other tanks.

The table was originally published by Niels Jacobsen, but that doesnt say they weren't from Ag.

 

conversations like this are good for several reasons. First, it is a reminder that something has been past due. The 18mo Giesemann middays on the 120g were starting to look dim to me lately , .... in fact the ends on the 48" bulbs are black... so i just ordered replacements. If the bulb degrades in blue, green and red spectrum equally, i can check the stats on my flashless photos.... to see if there has been change in f stop and/or shutterspeed i have been using. If interesting, i will post.

I might as well tweak the CO2 and add Glut. It wont hurt.

I am still confused about why the plant is translocating nutrients to the new leaves if there is not a N,P,K,Mg nutrient shortage. Is the plant less capable of nutrient uptake (or does it require more work) when CO2 or light are insufficient?

 

Excel dosing question:

thanks... did not know that!

Regarding excel dosing, the SEACHEM label says 5ml/10g (2ppm Glut) after water change and 1ml otherwise. The latter is 0.4ppm GL

Tom and others- are you suggesting 5ml /10g or 60ml per 120gal every day? NO wonder that would be expensive. That is the dose i thought folks used to control algae and not on a daily basis.

Thanks!

 

I think folks who use it at 2x strength are normally using it at half the stength that you mention, NO? So that brings it to a max of 2ppm.

For aquarists, i think the biggest dangers are sniffing Excel directly out of the bottle (as it is poured) or getting it on your skin. I am always very careful to do neither. I also am sure to rinse the cup and that i use for dosing. Because of known toxicity, i did not want to purchase Glut concentrate higher than 2.5%. I hear people saying that Glut smells like green apples. I think that is because of the extender, but i will leave it up to others to tell me what it smells like.

Once it is diluted in the tank, i dont think there is any real danger. In the medical field where it is used for sterilization-- 1-2% solutions -- there is ample opportunity for vapors to form in the ambient air. In the tank, the concentrations are 2ppm (1/1000th of a 2% solution), and what evaporates is very minor. Anyway, most any stuff that is toxic is not bad in very low concentations.
"The solution to pollution is dilution."