[Wet Thumb Forum]-Lets talk about iron and micros. Experts only. - Page 3 - Fertilizing

Roger Miller · 01-12-2005, 05:23 PM

Marcel,

I'm glad that seems to be working out for you.

My tap water has a pretty odd and variable chemistry and on-again off-again magnesium deficiency is a problem that I learned to deal with about 7 years ago. All of my tanks are dosed with magnesium now whether the plants show deficiencies or not. I don't think of it much at all anymore, and when I do I don't think of it as fertilizing my tanks -- I think of it as fixing my water.

For 6 of the tanks I mix epson salt with the water I use for water changes. For the remaining tank I add epson salt along with the potassium nitrate dose after each water change. I'm not real picky about how much I add; enough to increase hardness in the tap water by a degree or so seems to be more than enough.

Roger Miller

AquaLung · 01-27-2005, 05:19 AM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Roger Miller:
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. <HR></BLOCKQUOTE>

Thanks. Do you think a Sodium concentration of 34 mg/L is detrimental to plant growth?

TWood · 01-10-2005, 06:48 AM

As a follow-on, here's a comparison of products:

http://www.gpodio.com/fert_table.asp

An excerpt below. What's not clear to me is whether or not they are using the same method to calculate percentages. By weight, volume, or molecular weight? The ratios are way different, and may be explained by differences in the accounting method.

TW

Roger Miller · 01-10-2005, 04:57 PM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Marcel:
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? <HR></BLOCKQUOTE>Analyses are almost always cited as weight percents. That's true for the iron chelate and for the analyses that Tom posted earlier. Unless something says otherwise, assume weight percent.
<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>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. <HR></BLOCKQUOTE>Sure.
<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>How do you dose your iron chelate? <HR></BLOCKQUOTE>In my two hungriest tanks I use SeaChem's Flourish Iron (ferrous gluconate) and dose about 0.33 ml/day per 50 gallons. In other tanks I dose Flourish comprehensive. I have in the past used ferrous gluconate tablets broken in pieces as substrate amendments. They work very well for targeted dosing.

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>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? <HR></BLOCKQUOTE>I'm not sure why you dose both flourish and CSM+B; I also don't know why you would stop dosing either of them while you experiment with the iron chelate.

The symptoms you describe sound like symptoms I might assign to an iron deficiency. But the iron level you report should be plenty. There are other things that cause similar problems. You might confirm that the problem is an iron deficiency by putting 1/4 of a ferrous gluconate tablet (from the vitamin section at the grocery store) in the substrate below one of the sick plants. If the problem is an iron shortage then that plant should quickly recover. Other plants probably will not.

I've heard other people report that the PMDD method worked at first then later stopped working. I don't really understand why that would be true. One possibility is that the tank and filter develop a bacterial population that consumes the chelate and precipitate the iron before plants get a shot at it. That kind of behavior happens all the time in things like waste treatment facilities but I've never heard it established as fact in an aquarium. There are other possibilities.

If there is such a specialized bacterial population it might be possible to correct the problem by switching to a mix with a different form of chelate. I think CSM uses EDTA, but TMG used DTPA. EDDA (I think it is) would be another option. Ferrous gluconate is also a possibility, but probably one that would require a different dosing proceedure to get the same result. The bacteria would be specialized to the original chelate but not trained to the new chelate, so the plants would have a better shot at the iron. After a while the bacteria would retrain to use the new chelate then you could switch back to the original. And on and on...

Anyway, that's barely educated speculation.

Roger Miller

TWood · 01-09-2005, 03:22 PM

I'm no expert (few here are) but...

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>It can take weeks for plants to respond to micros. <HR></BLOCKQUOTE>

I use the color of new growth on h. difformis as an indicator for low iron (Fe) - Pale growth means Fe is too low. The plants respond within HOURS after adding CSM+B to get Fe at 0.1ppm.

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Do we need more iron than Plantex CSM+B offers? <HR></BLOCKQUOTE>

That question makes no sense and reveals an underlying confusion. CSM+B has a known amount of Fe in it. If you want more Fe in the tank, then add more CSM+B to the tank. Use the Fertilator to dose as much as you want to get to a target level:

http://www.aquaticplantcentral.com/forum/fertilator.php

Don't bother making a solution, just add the dry powder until the calculator says you've added enough. I usually dose to get 0.1 ppm Fe.

Remember too, the dosing for Fe, when part of a micromix, is also used as a proxy to get the other micronutrients correctly dosed. The idea is, that if you dose Fe to a certain level, then all the other micros will fall into line in the proportion that they exist in the micronutrient mix. Just dosing Fe alone doesn't accomplish that broader goal.

TW

Antonio Trías · 01-16-2005, 02:18 AM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Copper chelates might be broken down by a number of other factors.

<HR></BLOCKQUOTE>

Which were these factors Roger?, and not just for Cu also for the other non ferric chelates, are all them the same?

Thank you in advance

Maurici · 01-15-2005, 09:08 AM

Hi all,
I have two questions more for Roger:
1- I would like to know if the breakdown of Fe chelates by light is due to photoxidation or photoreduction.
2- Do you know about the chemical breakdown of copper chelates (used as algaecides)? is also a question of light activation?
Thanks.
Maurici.

wschalle · 01-23-2005, 07:21 AM

I personally use h. polysperma as my iron indicator. It lets me know within a day, and the colors range between pure green to reddish green to brilliant red with white veins.

I'm certainly no expert, but I generally add .25 ml of iron to my 10gal whenever new growth on the polysperma isn't red.

m.lemay · 01-12-2005, 04:46 PM

A quick update: It does seem to be a magnesium deficiency. After dosing my tank to 10ppm mag, the plants started to pearl more vigorously and the leaves on my ferns are beginning to green up. I didn't think that I would see results this quick.

Roger:
You are truly knowledgeable in this area. Though you didn't tell me outright that its a Magnesium deficiency, for lack of details on my part, the things you posted had me thinking critically about what could be going on in my tank

Thanks
Marcel

Maurici · 01-15-2005, 09:59 PM

Hi all,
First, thanks a lot to Roger, the answer is so clear.
Another thing, have you any preference or recommendation on the timing for dosing nutrients? I'm thinking in a possible better results of adding the Fe taking on account the lights out.
Regards.
Maurici