[timwag2001]

i've been dosing all of my ferts to ei. i have a 55g with 4wpg. i dose .53g of csm+b 3 times a week. so that's .17ppm 3 times a week for a total of .51ppm. but the reds on my plants just arent popping out like i think they should. i have broadleaf ludwigia, rotala indica, rotala wallichi, rotala singapore, and alternanthera reneikii.

what levels do you dose your fe at?

 

[timwag2001]

does anyone dose more than .5 ppm a week?

 

[Jeff5614]

Based on the fertilator, I'm dosing around 1 ppm/week by dosing 5 ml Flourish Iron 3x/week and 15 ml Flourish 3x/week. This is pretty much standard EI dosing including the optional additional iron.

 

[EdTheEdge]

I used to dose a lot of FE to get my reds to "pop" but they didn't. I think dosing FE to bring out the reds is an urban legend of sorts. IT might work for some and not for others though. YMMV. My plants respond mostly to K2PHO4, KNO3 and they simply go bonkers for Aquacare. The more I add the faster they grow and redder they get.

 

[Philosophos]

Reds are more of a NO3 limitation thing; I've seen it work and made it happen a bit. There may be something to light quality altering photosynthetic pigments as a method of adaptation, but that's unverified. Intensity is something I've seen discredited repeatedly.

Iron is hit and miss as far as studies go. Here's a good one on the subject of iron in some aquatic weeds: http://www.apms.org/japm/vol27/v27p57.pdf

Here's an article by Tom that includes a link to the above study: http://www.barrreport.com/co2-aquatic-plant-fertilization/2807-iron-uptake.html

The 2nd link is 404ing right now, but hopefully it'll be fixed.

Adding the extra iron does seem to help the tank out even if color isn't always promoted. Having switched from dosing .1ppm to .75ppm I'm noticing a big difference in how resilient plants are. Not a controlled experiment, but I think it's worth having others give it a try.

-Philosophos

 

[timwag2001]

thanks for the info.

i know that all that i mentioned was the reds on some of my plants. i had read at one site that not enough iron can cause death of the meristem. i've had some plants that i thought were suffering from symptoms of calcium deficiency. distorted leaf growth, damage and die off of growing points... could this be not enough iron?

switched from dosing .1 to .75 ppm how many times a week?

 

[Philosophos]

Iron has usually shown up as interveinal chlorosis when I've seen it. The persisting vein and nerves usually differentiate it from nitrogen deficiency.

Calcium deficiency is pretty rare; most water has enough in it, and a lot of fertilizers add more. If anything I've found most people identify carbon deficiency as a calcium deficiency because of their similarity in function. There's tons of resources talking about calcium deficiency, but not carbon, mostly because it isn't an issue until a plant is submerged. There's honestly very little in terms of carbon on nutrient deficiency tables.

Both .1 and .75ppm are numbers for weekly dosing on estimative index, so cumulatively they max out at .2 and 1.5ppm respectively.

-Philosophos

 

[Jeff5614]

FWIW, the red that I have in my tank just happens. I don't do anything in particular to try and encourage it mostly because there doesn't seem to be anything other than anecdotal evidence supporting all the different theories ( high iron, high light, etc. ) with the exception of limiting nitrates. It makes me wonder when additional iron or higher lighting makes reds pop for some people if they've just added what was missing in their setup to achieve optimal growth.

 

[Philosophos]

FWIW, the red that I have in my tank just happens. I don't do anything in particular to try and encourage it mostly because there doesn't seem to be anything other than anecdotal evidence supporting all the different theories ( high iron, high light, etc. ) with the exception of limiting nitrates. It makes me wonder when additional iron or higher lighting makes reds pop for some people if they've just added what was missing in their setup to achieve optimal growth.

Definitely a possibility. The funny thing is that by withholding NO3, you're creating a limiting nutrient possibly. I guess the real question is whether chlorophyll production being low enough to show underlying carotenoids cuts in to nonlimiting growth.

Nonlimiting nutrients that cover excess makes for some green plants, but perhaps some of this is luxury. Maybe there's a way to prevent luxury uptake of NO3 while pushing carotenoid production to excess in order to induce the colors we want.

One way or the other, it's the sort of thing that definitely needs more testing before we can come to a conclusion. Maybe the research is already out there with terrestrial ornamentals. I haven't found anything yet my self.

-Philosophos

 

[Jeff5614]

Here's a short but interesting thread from The Barr Report regarding Fe dosing.

http://www.barrreport.com/showthread.php?t=6203