[Wet Thumb Forum]-Lets talk about iron and micros. Experts only. - Fertilizing

m.lemay · 01-08-2005, 03:16 PM

I want to start a discussion about iron and micro dosing. The goal here is to get some real data about what works and what doesn't. It's my hope that we can come up with some real hard solutions to this perplexing little "mystery".

I know I'm not the only one that feels like theres no real substance to micro dosing.

Macros for the most part have been real simple. 10ppm nitrates, 1ppm phosphate, 10-30ppm potassium, simple right. Maintain a 10-1 ratio of nitrate to phosphate and alls well. Plus there's lots of room to experiment with fairly quick consequences when deviating from these parameters, which makes it fairly easy to determine cause and effect. Not so with micros. It can take weeks for plants to respond to micros.

Here's some thoughts or questions we might want to discuss:

Are iron tests really useless?
What about the Lamotte/Hach iron tests.
Do we need more iron than Plantex CSM+B offers? If so how much more?
Anyone using Iron Chelate 10% from GregWatson.com? If so, Whats your experience?
Whats your experience for dosing maximum color?
How much is too much micros?
Any other thoughts that would be relevant are also welcome.

I'd like to confine this discussion to planted tank enthusiasts who have something to offer in the way of real experience in this area.

Please don't post general questions about micro dosing in this thread.

Let the discussion begin.
Marcel

Roger Miller · 01-27-2005, 03:04 AM

I'm not sure where the low end for boron concentration is. I expect that 0.14 mg/l should be fine -- neither high nor low.

Roger Miller

TWood · 01-09-2005, 05:30 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Using tested iron levels as an indicator for other trace nutrients is an established practice. The chemistry of iron is different from the chemistry of other trace nutrients. As a result, iron is a very poor indicator of trace nutrient levels. <HR></BLOCKQUOTE>

Hey Roger,

But what about not testing for iron, but simply dosing a micromix to a mathematically derived iron level? Don't the micros then fall into line behind the iron at the ratios they are present in the mix? Which does raise the question, which ratio is correct? I suspect different agricultural micromixes are designed to address regional soil conditions.

Edit: Snarky comment removed.

TW

aviel · 01-10-2005, 07:21 PM

Marcel,

If you are using too much iron then *maybe* what you are experiencing is manganese deficiency -

See here http://www.spectrumanalytic.com/supp.../Mn_Basics.htm

"Mn:Fe Balance: Soils high in available Iron (Fe), or high Fe applications can reduce Mn uptake. "

Manganese deficiency symptoms are similar to those of iron deficiency: "Because Mn is not translocated in the plant, deficiency symptoms appear first on younger leaves. The most common symptoms on most plants are interveinal chlorosis. Sometimes a series of brownish-black specks appear in the affected areas"

I had yellowish rotala green when I way too much iron in my tank.

And I said *maybe*.

Which leads me to my second observation. My gut feeling is that using CSM+B the amount of iron that I can add to my tank is limited. I did a survery here once and those who use flourish/flourish-iron dose ~ 0.2-0.4 ppm iron per day! (I know Roger, i know...) - my experiments for achieving this daily dose using CSM+B failed. Given my 2.6 wpg/PH=6.1/26-27C it seems like CSM+B can produce ~0.03 ppm per day ~max. Beyond that the chelate just accumulates to toxic levels and this is how I got the manganese deficiency.

I really would like to know if others are experiencing the same or I was the only one in the world trying to dose that much iron through a chelated mix.

And finally, I wouldn't restrict any thread to the "expert" level. U might discover that you can learn a thing or two from the experience of us newbies...

Aviel.

Roger Miller · 01-09-2005, 06:47 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by TWood:
But what about not testing for iron, but simply dosing a micromix to a mathematically derived iron level? Don't the micros then fall into line behind the iron at the ratios they are present in the mix? <HR></BLOCKQUOTE>I can't think of a reason in the world why they should. That's why iron is a lousy indicator.

Iron hangs around in the water as long as it stays chelated then drops out of solution very quickly when the chelate breaks down. That breakdown rate depends on the kind of chelate, the pH, light spectrum and intensity, temperature and probaby a few other things. Very little of the iron actually gets used by plants. None of the other trace elements react the same way. Some of the trace elements have little tendency to react or precipitate and may stay in the water until plants use them. Copper, zinc, and nickle do not precipitate but might adsorb to surfaces -- whatever they do they certainly wouldn't do it at the same rate as chelated iron. Manganese tends to react a little bit like iron, but not under the same conditions and probably not at the same rates.

If you use iron as your standard (regardless of whether you test it or calculate it) then nutrients that are more conservative (less reactive) than chelated iron tend to build up in the water. Nutrients that are less conservative (more reactive) than chelated iron will tend to be depleted. You could get some real different behaviors out of two different trace mixes that are identical in every regard except the chelating agent used for the iron.

For the record, I use a commercial trace mix without iron and a commercial iron solution and I don't test or calculate a damned thing. Doses are determined from the manufacturer's recommendations and adjusted based on plant growth and on the principle that the dose of potentially toxic additives should be minimized.

I can dose iron rather freely because its toxicity is fairly low. In the case of other traces:

I dose a trace nutrient mix at the lowest rate necessary to avoids deficiency problems in most plants.

I try to avoid dosing things that the plants don't need. My tap water contains plenty of boron so I use a trace mix without boron.

I use substrate amendments to treat cases where one plant shows a deficiency that isn't shown by other plants in the same tank. That lets me avoid using higher doses.

I use small daily doses to avoid the high concentrations that result from a large dose delivered at longer intervals.

The possible behaviors of trace elements in the aquarium can vary greatly based on conditions in the aquarium. The need for dosing can be even more variable than the behavior of the chemicals. It's (to me) laughable to think that the trace nutrient needs of all aquariums can be satisfied just by using a trace mix and dosing to a predetermined iron level.

Roger Miller

m.lemay · 01-10-2005, 09:40 AM

TWood:
I apologize if I seemed "snarky" earlier. I didn't mean to be.The very reasons Roger has listed above are why I started this thread to try and get some more relevant science.The old PMDD theory of dosing micros till you get .1ppm of iron used to work for me too.

Now I'm dosing what seems to be outragious amounts of micros while my java fern suffers from what looks like iron deficient chlorosis, and my E stellata is growing in pale, E parvulus is also starting to show signs of yellow. Its my speculation that its an iron deficiency since all my macros are kept up to snuff.

Roger:
I just recieved some Iron Chelate 10% from GregWatson.com but I'm not sure how to come up with a dosing regimen because I'm not sure how to do the math (chemistry challenged). Do you know if 10% is by weight? Does 1 kilo(1000 grams) of this stuff yield 100 grams of iron? If that is the case, then I can do the math to get .1ppm concentration in my 75 Gal tank.How do you dose your iron chelate?

What I was thinking about doing is laying off the CSM+B and the flourish and just dose the iron chelate for a couple of weeks to see if things improve, what are your thoughts on that?

I'm not expecting tons of replys to this thread. I've been doing planted tanks for about 5 years and I'm a mod over at ThePlantedTank, I'm not new at this. I'm just trying to get some better science in the micro department, and hopefully everyone can benefit from this discussion.

Sincerely
Marcel

AquaLung · 01-26-2005, 08:19 AM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Roger Miller:
...My tap water contains plenty of boron so I use a trace mix without boron.... <HR></BLOCKQUOTE>

I just had my water tested and I have 0.14 mg/L Boron. Is that considered high or low for a high-light CO2-injected planted tank?

m.lemay · 01-11-2005, 12:31 PM

After a bit of deductive reasoning on my part, I think its a magnesium deficiency. I haven't dosed magnesium in over a year, my tap water is pretty soft at 1-2 Dkh,1-2Dgh. I put a little crushed coral in the substrate a long 3 years ago so I wouldnt have to dose calcium carbonate at every waterchange. Between waterchanges the kh will vary from 3-6 dkh,my ph is locked in at 6.9 which gives me a variable co2 rate of between 15-about 25ppm CO2. Because my water is so soft I recieve next to zero Mg from tap water. My yellow symptoms are appearing in old growth java ferns and older Hairgrass which seems to be consistent with "Chucks deficiency symptom chart". I'm crossing my fingers. I just upped Mg to 10ppm calculated from chucks page using Epsom salt.

None of these symptoms appeared till just recently when I changed out my old 9325Ks GE bulbs a month ago,for new ones plus I added 2 more for a total of 330 watts over 75G. I also pumped up the CO2 recently to get my dwarf Hairgrass to spread and thicken.

I'll let you guys know how things pan out.

Anyone here using a Lamotte Iron test kit?

I think its time to change my profile to reflect my actual tank specs. Will do now.

I'd still like to see this thread continue as some very good informative material has surfaced here.

Thanks
Marcel

TWood · 01-11-2005, 04:38 AM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>I really would like to know if others are experiencing the same or I was the only one in the world trying to dose that much iron through a chelated mix. <HR></BLOCKQUOTE>

I've been using CSM+B for several years and haven't seen anything like you describe. However, I'm going for something closer to minimum rather than maximum levels. If you suspect a build-up of chelates to toxic levels (how do you know?) then why not do several water changes and then wait for iron deficiency to show up?

I do 20% weekly water changes and dose CSM+B when the new growth on h. difformis comes in pale. Then I dose it to get about 0.1ppm iron and wait. Depending on how thick the tank is, it can take a week or two before a new dose is needed. Keep a record and you'll see a pattern emerge.

More is not always better.

TW

m.lemay · 01-09-2005, 04:24 PM

You're assuming that Plantex is the perfect mix for all plants all the time.

The question makes a lot of sence in that ,what if as your dosing plantex your overdosing unnecesary and potentially dangerous elements such as copper (present in Plantex)in order to obtain the optimum iron level. All the other stuff you stated is all true but far too simple for this discussion.