SniperLk

Hello,

I'm a bit confused about the Iron dosing recommendations from EI and Seachem.

According to the Seachem Dosing Chart, they recommends to use 6 times per week 5mL of Flourish Iron for 200L. That's to say 1.5ppm of Iron per week (as stated by the APC fertilator)

And EI advises to drop 1.8g of Plantex CSM+B each week for the same tank, which represents 0.5ppm. (and EI is supposed to dose in large excess...)

So why such a difference ? Is there any errors in Seachem dosing chart or something ?

Thanks

Left C

Following the Seachem dosing chart works well with low to moderate light aquariums. If you have higher lighting, just dose more.

I wrote the Seachem doinh calculator in the fertilizing sticky. It hasn't worked since servers were changed.

I can send it to you if you PM me your email address.

The reason that F. Iron is suggested to dose daily is because the iron in the F. Iron isn't available for much over 24 hours.

SniperLk

Hi, so you think that I should dose even more Flourish Iron with a heavy planted tank, but it's still 1.5ppm/week, that's to say way more than EI recommendations (designed for heavy planted tank) !!

That's what I don't understand...

Left C

Let's say that your aquarium has 170 liters of water. Seachem recommends dosing 4.5 mL of F. Iron daily along with 3.7 mL of Flourish 2x weekly.

If you are using other products along with Seachem's line; you should adjust accordingly.

Your best response may be to ask this question in Seachem's forum on various sites.

SniperLk

Hi and thanks for your answer.

Ok so for 170 liters, if we follow seachem recommendations for moderate light aquariums, we add per week :
0.1ppm of iron (3.5*2=7mL of flourish) + 1.5ppm (4.25*6=25.5mL of Flourish Iron) -->1.6ppm of Iron each week.

Then if we look at EI recommendations for high light aquariums :
3*1/8 tsp of CSM+B per week which represents 0.15ppm of Iron each week (thanks to the fertilator again)

--> So seachem recommends to add 10x the amount of Iron that recommends EI (which the aim's to dose a lot (too much) nutriments !).

All I want is to understand why such a difference.. (maybe the fertilator is simply wrong ?) It's really weird...

Left C

I just double checked the numbers and our numbers basically agree. They are below.

It seems that Seachem recommends quite a bit more Fe than EI. I don’t know why.

There are some problems with the fertilator and Seachem's products. The fertilator says that there is iron in practically all of Seachem's line of ferts (unless it's been fixed), but that doesn’t make any difference here. All of our products here contain Fe.

I don’t think that the Fe calculation of CSM+B using the fertfriend is a problem. After I calculated the weekly EI dosing for 3/8 tsp or 30 mL of Trace I found that all the ppm’s of Fe from the three products are basically very close to each other. That's below too.

I use the fertfriend calculator sometimes: http://www.fishfriend.com/fertfriend.html

I plugged in 170 liters into my Seachem calculator and you dose:
4.5 mL of F. Iron 6x per week and 3.7 mL Flourish 2x per week

Then according to the fertfriend calculator:
4.5 mL F. Iron = 0.2647 ppm of Fe per dose
3.7 mL Flourish = 0.0696 ppm of Fe per dose

Then (6 x 0.2647) + (2 x 0.0696) = 1.7274 ppm of Fe per week – This agrees with what you are saying.

Then using EI for a 170 liter aquarium = 1/8 tsp of CSM+B or 10 mL of Trace 3x weekly
1/8 tsp = 0.12 ppm of Fe per dose or 0.36 ppm of Fe per week from the fertilator
10 mL of TMG = 0.0411 ppm of Fe per dose or 0.1233 ppm of Fe per week from the fertfriend
10 mL of Flourish = 0.1882 ppm of Fe per dose or 0.5646 ppm of Fe per week from the fertfriend

To make the above paragraph easier to read, I’ll list each product’s ppm of Fe per week. We can see that they are very close to each other:
CSM+B = 0.36 ppm of Fe per week
TMG = 0.1233 ppm of Fe per week
Flourish = 0.5646 ppm of Fe per week

Again, I don’t know why Seachem recommends more Fe than EI. This is a question for Seachem’s tech representatives to answer.

Do you know what you get when you cross an elephant with a rhinoceros? ….elephino!

ray-the-pilot

I think the problem you are facing is that no one really knows what is the right level of Fe!
Fe has very complex water chemistry. If you throw in 0.1 ppm of Fe in your tank it will go away almost instantly. At ordinary pH, Fe+3 and Fe+2 will precipitate out as their respective oxides. Typically people add chelating agents like EDTA to help keep the Fe in solution. Even with these, the Fe eventually precipitates out into the substrate. Now you see that the longer you can keep Fe in solution, the less you have to use but there is a trade off. You have to add more Chelating agents and keep the pH as low as possible.
Now here is another point. The Fe that precipitates out into the substrate is not gone! Most rooted plants have the ability to extracted Fe out of the substrate. This is how they get Fe in real life since there are no chelating agents in nature. Having Fe in your substrate is not at all a bad thing; since, the plants can use it or not and it is not contaminating the water environment.
My feeling is that it doesn’t matter a lot whether you add 1.5 or .15 ppm per week as long as you do 20% - 30% water changes as well.

SniperLk

Glad to see that my math was good

About asking Seachem’s tech representatives I don't think it will help. They gonna say that their products work great, their research showed that.. bla bla bli bla bla bla... --> they don't really care about what someone recommends..

ray-the-pilot : Yeah you must be right.. it would be nice to see what are the effects of overdosing Fe on a tank...

Left C

The version of EI at TPT has extra Fe added: http://www.plantedtank.net/forums/wa...-regimes_.html

hoppycalif

Shortly after Greg Watson began selling dry fertilizers he offered CSM+B with extra iron mixed in to double the amount of iron. After a short time he found that the extra iron was of no benefit, so he dropped that product. I bought my CSM+B plus extra iron from him when he was still selling it and that is all I have used since then. I only do so because I'm too cheap to toss out perfectly good trace element mix. My opinion is that you don't need extra iron, but it also doesn't do any harm if you use it.