Dry trace mix and EDDHA iron

[dmachado]

Hello,

I need help to confirm the ratios for my trace mix and iron mix.

I have access to absurd amounts of dry EDDHA 4,8% Chelated Iron and also a dry trace mix with the approximate content:

Iron (Fe) 7,4%
Manganese (Mn): 3,3%
Zinc (Zn): 0,6%
Boron (B): 0,71%
Copper (Cu): 0,25%
Molibdenium (Mo): 0,1%

I know EDDHA will tint the water red so dosing should be done with lights out.

As for the trace mix, I think it's well balanced. I am aiming to dose at about 0.74ppm Fe to my 300L aquarium, so if I add 150g of the mix to 1000ml of water, dosing 20ml at a time, 3 times a week, I would get:

150g x 0,074 = 11,1g = 11.100mg added to 1.000ml, whem dosing 20ml, 222mg per dose, meaning 0,74ppm Fe for the 300L water volume.

The other elements would be:

Manganese (Mn): 3,3% 0,33ppm
Zinc (Zn): 0,6% 0,06ppm
Boron (B): 0,71% 0,071ppm
Copper (Cu): 0,25% 0,025ppm
Molibdenium (Mo): 0,1% 0,01ppm

In case I want to get Fe to 1ppm or over, I would use the EDDHA 4,8%. The math would be the same, replacing the ratio.

Can I get an opinion on this please?

Thank you.

 

[ceg4048]

It's not clear what opinion you are looking for. It might be better if you asked a more specific question. As far as I can tell by the numbers you listed the trace mix looks fine. EDDHA is useful in hard water and high pH situations (pH 8 and above) due to the strong chelate bond with the Fe.

I see no need to make special efforts to dose when lights are out, but if that is convenient for you then there are no issues. The pink water will occur whether the lights are on or not, so this makes no difference.

It's also not necessary to raise the Fe concentration level to 1ppm or more and if you use a lot of the powder to get to that level then the pink water will be even more of a problem. A weekly Fe dosage of 0.5 ppm will be more than enough and you can get by with less than that if the lights are not too bright.

Finally, ratios are irrelevant, so it hardly matters what trace mix is used. The point of dosing nutrition is to avoid starvation, not to micromanage ratios. Life is a lot simpler if we avoid thinking about ratios. In any case, what is dosed is not necessarily what is taken up by the plants, so ratio management becomes an illusion.

Cheers,

 

[dmachado]

Hi Clive, thanks for your reply.

The lights out dosage was just for not seeing the pink water, but I read somewhere it can last quite some time, so I may try it at lower dosage.

Anyway, if I get 0,74ppm from the trace mix it's right where it should be, so I'll stick to this first dosage for several weeks, and see how the plants are doing (I'm also dosing EI - lots of N and K, and Mg, P is "natturally ocurring" with all the fish food). CO2 is not forgotten.

Thank you.

 

[ceg4048]

OK, fair enough. Please be advised however that "naturally occurring" NPK is the enemy and that's where all the trouble starts. In a CO2 enriched tank, you really want to avoid, as much as possible, nutrition from food because these are toxic and anoxic sources of nutrition.

The idea of EI is to avoid naturally organic sources of nutrients in favor of inorganic sources. That's accomplished by frequent and large water changes. This is a key and fundamental approach to fish and plant health in a closed system such as we have. The amount of Iron you are adding will have a minor impact on plants health and growth compared to your management of NPK.

Cheers,