What trace mix?

[keymaker]

I just received my concentrated Trace Elements Mix (Micro+) that contains the following:

Fe 38 g/l
Mn 9.6 g/l
Cu 0,48 g/l
Zn 2,4 g/l
B 3,5 g/l
Mo 0,70 g/l
(HEDDTA chelates)

I did not find anywhere the EI dosing recommendation for the traces. Can you tell me what is the non-limiting range for these? I wonder how much to dose from this???

Edit: It is actually HEEDTA chelates, not HEDDTA. Sorry.

 

[JamesC]

I did not find anywhere the EI dosing recommendation for the traces. Can you tell me what is the non-limiting range for these? I wonder how much to dose from this???

Dissolve 25ml traces in 500ml water to give you standard Tropica TPN strength trace solution. Then dose this as normal EI recommendations. ie, 5ml per 100 litres 3x a week.

HTH
James

 

[keymaker]

James, thanks for your guidance! Cheers.

 

[Henrik]

Where am I going wrong - 38g/l Fe gives you almost 1 gram of Fe in a dose of 25ml gives you 2g/l if you dissolve this dose in 500ml - which makes 0.2% Fe as opposed to 0.08% in the standard TPN strength mix, i.e. more than double the strength?

 

[keymaker]

Where am I going wrong - 38g/l Fe gives you almost 1 gram of Fe in a dose of 25ml gives you 2g/l if you dissolve this dose in 500ml - which makes 0.2% Fe as opposed to 0.08% in the standard TPN strength mix, i.e. more than double the strength?

I guess - nowhere! James presumably did not take the double Fe value in this particular Micro+ mix into consideration when posting his answer. Remember, that Haack has two types of Micro+ mixes with HEEDTA chelates, the one I ordered contains double Fe. The other one contains the "normal" amount, you can order that too but I chose the one richer in iron...

The rest of the traces should level with the TPN values. I did a small Excel calculation to compare my values to TPN+ and James' DIY TPN+ values:

All other levels are about the same.

 

[Voo]

AE traces are fine and many people use them with excellent results. Currently if you want to use a decent iron chelator such as HEDDTA you need to buy Tropica's TPN. EDTA can cause problems if you have hard water as it breaks down quite quickly releasing the iron. This free iron then reacts with compounds such as phosphate to create iron (III) phosphate which is insoluble. This is often seen as an orange buildup of within filters and substrates. I find I have this problem which is why I'm looking at alternatives.

Garden Direct's chelated traces I think use a different chelator as their mix is green in colour. Iron EDTA is red in colour as the iron is in the ferric (3+) state. Ferrous (2+) iron is green in colour. It is possible to change ferric iron into ferrous iron by adding a reducing agent such as ascorbic acid. This is why people who add ascorbic acid to there trace solutions find that the solution turns green.

James

To pick up on something that James mentioned above, i get a lot of this brown/orange gunk in my filter, especially around the impeller. I use Garden Direct's chelated traces, and our area has hard tap water.

Is this due to an overdose / excess iron? Or does it have the opposite effect, taking the iron out before plants get a chance to use enough?

Could this also be causing Phosphate defficiencies in my tank? Even though i'm overdosing, i'm still getting green spots appear and will have to overdose even more.

How does this buildup affect the impeller, with it being iron etc?

Also, is there any way around this? Thanks

 

[JamesC]

That brown/orange gunk could well be iron (III) compounds. I used to think that this buildup was due to the amount of iron I dosed but have now changed my theory on this and believe that it is because of using a cheap trace mix that uses EDTA as the chelator. Hard water seems to make matters worse, or more likely it's the higher pH that makes the EDTA less stable. The EDTA releases the iron quicker which results in the iron reacting with compounds such as phosphate which results in and insoluble precipitate being formed which either sinks into the substrate and/or is taken out by the filter. I found as you that I got a large buildup around the impellor housing. btw the iron (III) phosphate that drops into the substrate may eventually be reduced to iron (II) in and be taken up by the plants so it's not all lost.

It's quite common for tanks that use hard water to experience a slight cloudiness when dosing Fe-EDTA based traces. Switching to Tropica TPN traces nearly always clears this up. I have for some time now been dosing with Fe-DTPA which has improved water clarity. Also the brown/orange buildup seems to have reduced but need to monitor for longer to be sure. For the past couple of weeks I've switched to Fe-HEEDTA which is the same chelator that is in Tropica's TPN range, so hopefully should also produce excellent results. Water clarity is great compared to when I dosed Fe-EDTA.

How much PO4 and Fe is taken out by precipitation is extremely hard to say. One thing that I always suggest is that if you think you have trace problems or you get tank clouding is to switch to Tropica TPN and see if that improves things.

The only problem I found with a buildup around the impellor housing is reduced flow.

James

 

[Voo]

Thanks James.

I've been noticing a slight cloudiness in one tank which i've been dosing normal trace amounts. My other (shrimp) tank i don't dose as much due to the high copper levels and the water has stayed clear. I've been thinking about getting a new trace mix so now seems as good a time as any.

Do you know of any other sources of Trace mix containing Fe-DTPA or Fe-HEEDTA that would allow me to mix my own solutions?

 

[Voo]

I've stumbled across this

0.36 % Fe (iron HEEDTA);
0.08 % Mn (manganese EDTA);
0.4 % Bo (boron monohydrate);
0.09 % Zn (zinc EDTA)
0.06 % Mo (sodiummolybdate)

No copper though... great for shrimps, but is that likely to lead to deficiencies, or is it possible to get away with the little copper that's in the tap water?

£3 a litre from here