tsunami

Through my experience, I have come to realize that aquariums with very intense lighting seem to require very high Fe/micro levels to remain healthy. Or perhaps the water hardness determines the amount of Fe/micro dosing necessary to grow healthy plants? I am not sure.

Last year, when I setup a planted aquarium in Chicago, I opted for a high light tank with 3.95 w/g. To overcome the problem of coverage, I ran two normal flourescent tubes under a reflector in the front and middle while the back had a row of three 13w compact flourescents from AH Supply. For such a shallow tank, this is a lot of lighting! Started with a Flourite substrate, and then switched to Eco-complete over Fertiplant + this year.

In this tank, for the longest time, anything in the Rotala genus or Didiplis diandra failed. Myriophyllum tuberculatum did not do well either. The Rotalas (Nanjenshan, wallichii, 'Green') would remain small and stunted, shooting out the occassional sideshoot which also stunted. Didiplis diandra also did not grow. It grew well for a week before turning white at the tip, crinkling, and developing spots of necrosis (dead brown spots).

I tried everything. The "high levels of K+ hurt plants" discussion was raging at the time, so I tried witholding potassium for a few weeks. Nothing happened. The plants only seemed to grow even slower. I then tried to increase trace levels by dosing Flourish Trace (no iron). The increased micro levels did nothing to help. I increased PO4 levels. Nada. I then finally increased Fe and then results began to show. I increased my dosing from 10mL weekly of Flourish Iron to 15 mL weekly (spread throughout the week, of course). The Didiplis diandra began to recover and produce healthy, lanky green shoots. Cool! I pushed the envelope even further by increasing 15 mL to 20 mL a week (which most would consider an astronomical amount to add to a tank). The Didiplis diandra went from lanky and green to robust. The internodes shortened, leaf span increased, and the plant became a deep orange to red color. I tend to use Didiplis diandra as an Fe indicator nowadays because of this experience. Rotala wallichii also works very well.

Currently, this is what I am adding to my two aquariums to get the same results with my Fe sensitive (?) plants:

55g: 15mL Flourish, 15 mL Flourish Iron weekly. 2.55 w/g. KH4, GH 5.

20g long: 18 mL Flourish, 18 mL Flourish Iron weekly. 3.95 w/g. GH 12,
KH 9.

I have often heard from Erik Leung, Ben Belton, others that high Fe/micro levels are the key to being successful with intense lighting. I've also read from Karen Randall that higher Fe/micro levels are necessary to grow plants like Rotala macrandra in harder water.

Which is the case? Any thoughts?

Carlos

HeyPK

I have had a feeling for a long time that the Rotala species need especially high iron levels, with R. macandra and R. wallichii needing higher levels than R. indica/rotundifolia. When Rotala goes bad, the new leaves get small and sometimes distorted. The growing tip can quit. The fact that the new growth is not pale unless the deficiency is especially severe makes it not look like "classical" iron deficiency.

I once had a beautiful stand of R. wallichii growing in a pot of soil/composted manure mix. It was a flaming orange color, but it was starting to shade out my other plants. I cut it all back down to 3 inch stems, and took the top portions to the LFS, confidently expecting healthy regrowth from the cut stems. After all, they had a nice root system in that soil/manure mix. I got hardly any growth at all. Tiny whitish stems with few distorted short, white leaves would grow a few millimeters and then die. I thought, "This can't be iron deficiency, it must be calcium deficiency." Adding more Ca didn't help, and I lost the species (again!) I am sure now that it was severe iron deficiency, not calcium deficiency, and, further, the plants either get their iron from the water, or they become unable to get it with their roots when they are cut back.

There is one other micro that behaves chemically like iron---manganese. It also tends to precipitate out when in the oxidized form (unless chelated) and be soluble when in the reduced form. We probably have to worry about levels of both iron and manganese. The other micros---boron, copper zinc, molybednum, probably stay soluble and are not lost except by plant uptake. We may only have to dose Fe and Mn weekly, but not the others.

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tsunami

Paul,

That is exactly what my nanjenshan looks like when I don't keep traces/iron high enough!

Carlos

HeyPK

I just figured that for your high light 20 gallon tank you are dosing iron at 4.5 mg/liter weekly!!! That sure is a lot higher than than the recommended dose of about 0.25 mg/liter! I have suspected for a long time that many aquarium plants require really high iron to do well. In nature, they probably grow where some portion of the water coming into their stream or pond comes from iron rich water seeping out of the soil. I wonder if the plants growing high up near the beginnings of streams get a lot more iron than those in larger lakes or rivers.

I would like to see some of the plants in your high light tank, now that they are getting plenty of iron.

Wheeler

Carlos,

I have a 20g (standard) with 2x55w PC's. If I don't add, 4ml of Fe daily then I see reduced color and growth ultimately resulting in meristem death. At one point I was adding 10ml of Fe (SeaChem) *daily* and still seeing improvements. I couldn't on like that or I'd go broke-- See below.

The lights are zapping the chelators before the plants can get at the iron. Photo reduction is the phenomenon I believe.

I redid the tank with a super rich substrate (it had plain gravel) and that seems to have taken alot of the demand from the water column. I'm still dosing 4ml each traces and Fe daily to keep up, though.

Gomer

Can someone do the math for me since we are on the subject...I forget the base numbers to calculate ppm Fe

3tbs plantex CSM+B into 500mL

Dose 1mL 3x/week per 10g

Thanks!

cS

I think each ml of the Plantex CSM+B solution adds 0.17 ppm Fe to a 10 gallon.

GIVEN:
(1) Plantex CSM+B is 6.53% Fe ( www.thekrib.com/Plants/Fertilizer/pmdd-tim.html )
(2) 3 tablespoons Plantex CSM+B weigh ~50 g

THEN:
0.17 mg Fe / liter = ( 1 ml ) x ( 50 g Plantex CSM+B / 500 ml H2O ) x ( 6.53 g Fe / 100 g Plantex CSM+B ) x ( 1000 mg Fe / 1 g Fe ) / ( 10 US gallon ) x ( 1 US gallon / 3.785 liter )

Gomer

thanks a million!

plantbrain

People thought I was(am) INSANE when I tell them how much to dose in their tanks=> fear of algae.
But this is not the case.

I dosed 3-4x what many have/had been doing. Everyone was worried about trying to maintain the 0.1ppm range from PMDD paper.

Myself, being hardheaded and never listening decided I'd see what the plant health would be like if I added more, I did not have any laterite in my sand at the time, so why not add more to the water column?

There also was a similar issue with PO4.

Traces take awhile to show growth differences, typically I give 3 weeks.

I think also that the type of chelator plays a large role.
Hard vs soft water? Well, it could just be from the richer minerals present.

I with held some dosing on my tanks when I had very hard water and did not see a dramtic decline, but now with softer water I see it, so I'm not sure that harder water really needs more or not.

But your observations certainly are right in line with mine, after Claus mentioned to everyone that high traces are the norm for CO2 enriched tanks with higher light, folks started adding it and this became more accepted practice.

If you attempt mass ratio balances, it doesn't work or correlate well like K+, NO3, NH4, PO4, Fe all have big issues with other complexes and binding/bacterial losses.

This is why I have been telling folks for many years not to test for Fe, iron. It will not tell what your plant needs, NO3, PO4 have ranges, but the Fe is too sensitive to measure with a test kit and relate this to a range besides a dose frequentcy with a volume of traces: tank volume or plant biomass ratio.

Regards,
Tom Barr

tsunami

I went through a lot of species in this 20g tank this year, so I have a pretty good handle on which species are most sensitive to Fe/traces shortages. These turn white, stunt, decline, etc if iron is not dosed in large enough quantities

IME, they were:

Didiplis diandra <-- twisting, white leaves with brown spots... death of meristem
Eusteralis stellata (Pogostemon stellata) <-- pale, death of meristem
Myriophyllum tuberculatum (also known as mattogrossense 'red') <-- ugly brown color, long internodes, death of meristem
Rotala sp 'Green' <-- twisting, curling leaves
Rotala macrandra <-- small leaves, death of meristem
Rotala macrandra v 'green' <-- loss of color, small, death of meristem
Rotala sp Nanjenshan <-- remains small, death of meristem
Rotala wallichii <-- small, lack of color, death of meristem

In the same tank, Hottonia, Micranthemum umbrosum, Ludwigia arcuata, Ludwigia brevipes, and Rotala indica very grew well.

The addition of extra iron/traces helped the Didiplis diandra especially. It went from white and deformed to lanky and green and then on to robust, huge, and orange. Pretty amazing.

Carlos