Solufeed 2:1:4 - IFC - low on P,K,Ca - user error?

[LFNfan]

Hi
Prompted by some comments on another thread I have taken another look at the IFC and tried to reflect my current dosing regime in the calc.
Results seem to indicate I'm low on P and K and Ca, compared to full EI - I have drawn red 'boxes' around the % against target cells for ease of reference.
Would appreciate a second pair of eyes on the inputs and outputs and if I am low, suggestions for sourcing what salts to add.
I've nearly finished my current macros solution so it will soon be time to make up another one - would be great to make any changes in the next batch.
Many thanks!

 

[Wookii]

First off your targets are a lot higher than full EI - 3ppm PO4 is plenty, realistically 10ppm K is more than enough too. Also your Fe target is very high at 1ppm, 0.5ppm as a proxy for all micros is plenty.

Ca is a separate issue, and is not part of EI at all. Ca level isn't an issue (10ppm is plenty for plants) unless you wish to keep shrimp, in which case adding some Calcium Chloride or Calcium Sulphate will boost the calcium figure to your target.

Also worth bearing in mind, you might want to increase your water change volume to at least 50% weekly - your targeted 35% isn't really enough for an EI/high tech system.

As you are not using pure RO with custom remin (which I would normally suggest given the high carbonate content in your tap water), just increasing the proportion of tap water used in your water change should net you the increased calcium and the increased water change - two birds, one stone!

 

[Zeus.]

Results seem to indicate I'm low on P and K and Ca, compared to full EI -

We have to remember full EI is ferts in abundance also, so that even though you havent reached your target levels for all nutrients you may already be in abundance as @Wookii mentions above.
We also have to take into account that when we use the local water report that the levels of nutrients vary with the seasons, which is one reason some use RO/rain water to fill their tanks as RO/rain water has no nutrients so it only has what been added so easier to control.
Fert regimes are great when you first start the hobby, with time your plant husbandry will improve and you will know what your tank needs by watching the plants, which is the basis of @dw1305 duck weed index

Also worth bearing in mind, you might want to increase your water change volume to at least 50% weekly - your targeted 35% isn't really enough for an EI/high tech system.

+1, getting rid of the DOC (Dissolved Organic Compounds) is just as important has ferts in abundance for EI dosing.

The IFC only does the maths for the various regimes, clones, remin agents etc, choosing which one works well for your plants/tank is another story.

 

[LFNfan]

choosing which one works well for your plants/tank is another story.

Haha - exactly this. The penny dropped [edit]for me [/edit]. EI is probably not my benchmark.

I will have another look at my target regime based on @Wookii 's comments and update this thread.

In terms of husbandry, I am getting better at spotting Mg and Fe deficiency, based on experience.

Many thanks for your steers 👍

 

[_Maq_]

I agree with @Wookii except this:

0.5ppm as a proxy for all micros is plenty.

I strongly oppose using iron as a proxy for other micros, indeed, for any nutrients. Iron is very special, and in many instances has to be overdosed many times in relation to other nutrients. I strongly believe that the only correct approach to iron is strictly individual - just as much as to avoid signs of iron deficiency, no matter how much of other nutrients are supposedly there.
It's the other micros which should be dosed in relation to other nutrients, preferably nitrogen.

 

[Wookii]

I agree with @Wookii except this:

I strongly oppose using iron as a proxy for other micros, indeed, for any nutrients. Iron is very special, and in many instances has to be overdosed many times in relation to other nutrients. I strongly believe that the only correct approach to iron is strictly individual - just as much as to avoid signs of iron deficiency, no matter how much of other nutrients are supposedly there.
It's the other micros which should be dosed in relation to other nutrients, preferably nitrogen.

Whilst I might agree in principle @_Maq_ you have to accept that 99% of folks out there aren’t going to go to the extent of mixing their own micros, and so are entirely reliant on CSM+B pre-made mixes. So within that context, we have to use Iron as a proxy for other micros, since we cannot separate them.

 

[LFNfan]

My 'thing' with Fe stems from my 'variegated anubias' and 'netted frogbit', so I'm OK to go a bit heavy on the Iron.
I use Solufeed Sodium Free TEC for my micros and don't tinker with that mix, but I also dose extra iron separately from my micros.

 

[_Maq_]

you have to accept that 99% of folks out there aren’t going to go to the extent of mixing their own micros

But I believe it's not necessary. You can choose some of readily available exclusive iron fertilizers, and dose something like CSM+B as if there was no iron in that just to ensure other micros don't get missing.
@LFNfan seems to be doing exactly that.

 

[dw1305]

Hi all,

I use Solufeed Sodium Free TEC for my micros and don't tinker with that mix, but I also dose extra iron separately from my micros.

My suggestion as well.

cheers Darrel

 

[Wookii]

But I believe it's not necessary. You can choose some of readily available exclusive iron fertilizers, and dose something like CSM+B as if there was no iron in that just to ensure other micros don't get missing.

I suspect we're in agreement on the principle, but talking at crossed purposes on the terminology.

Yes of course, we can dose extra iron on its own - that's exactly what I do; I add Iron Gluconate to a CSM+B mix - but you still have to decide how much of the CSM+B to dose in the first instance, and that dose is typically chosen by reference to the iron element of the dose - not because that's necessarily our overall target iron dose, but simply because that's our 'proxy' value for the overall micro dose.

@LFNfan seems to be doing exactly that.

Yep, but he didn't specify that in the OP, so I didn't know he wasn't just using CSM+B to reach his 1.0ppm target, hence why I suggested that might be more micro's than he'd need. If that 1.0ppm is split between CMS+B and a separate iron addition, then that is of course a different kettle of fish.

 

[LFNfan]

Yep, but he didn't specify that in the OP,

My bad. I have the "CSM+B" and the Fe on separate lines in the 'micros' table of the IFC so it's pretty clear. Unfortunately I (wrongly in hindsight) didn't think necessary to provide that screenshot as I was just focused on the macros 😂

I see what you mean by Fe and other macros - if you only had a micros mix and wanted to go 'heavy on the iron', you would inevitably also be over-dosing the other micros in the mix.

 

[LFNfan]

Using @Wookii 's numbers I have updated my targets and with a bit of a tweak I'm at or around 100% for my macros.

In terms of making up my new batch I'm going to put the Solufeed and the epsom salt doses into the same container. I think this is OK? Up to now I have been dosing epsom salts separately once a week so to roll that into my new macros mix will save a bit of extra effort and make that salt more regularly available.

 

[_Maq_]

I predict you'll face nutrient imbalances (Mg?) and difficulties with iron.

 

[LFNfan]

I predict you'll face nutrient imbalances (Mg?) and difficulties with iron.

Thanks Maq. What would you advise my weekly targets should be in order to improve your predicted outcome re my Mg imbalance and Fe difficulties?

(I should note that I will be dosing additional Fe in addition to the micros mix. I will be aiming for 1ppm Fe overall)

 

[LFNfan]

... to try and answer my own question, this is to do with Ca:Mg ratios. My target is 1:1 but that is not optimal per other threads - I should be aiming for 3.2:1. Reluctant to up my hardness with more Ca so that means targeting 1/3 the amount of Mg?? No-win. 🤷‍♂️

 

[_Maq_]

What would you advise my weekly targets

I don't think that Ca:Mg ratio of 1:1 is the problem. Estimative Index is. With cca 30 mg/L nitrates and 3 mg/L phosphates you are way above what is natural and needed. With intense light and CO2, your plants will uptake a lot of nitrogen, perhaps, but maintaining nutritional balance will be difficult, I'm afraid.
3 mg/L PO4 in the water column will render all iron precipitate. You can possibly avoid that by using advanced chelates. But it's a bit funny - creating problems and then employing special measures to overcome them.

 

[LFNfan]

I have no CO2 and 30W of LED lights 12 hours a day . Light to moderate planting but with two decent sized plants (epipremnum and spider plant) with wet roots growing out of the tank.

Should I target 10 ppm nitrates, 20...?

I suspect Maq's own target would be at the very bottom end of the range of possible values so I'm automatically going to add 5ppm to whatever nitrate number you suggest

 

[_Maq_]

I suspect Maq's own target would be

Have a look here. You can browse the thread and see what plants grow well in such or very similar water without CO2 enhancement, without bio-filtration, and with DIY LED-bulb lighting.

 

[LFNfan]

Ive been following this thread but like a three year old - looking at the pictures, not reading the words.

Can I request a kindness: could you map the minerals in your formula 13 to the target dosing minerals in the IFC. I cannot tell how they line up between the two tables.

What I think I am seeing is < 1ppm nitrogen in your Portugals. Surely not?

Then, once those numbers are mapped, I suspect there will need to be some artistry applied, as I am mixing RO and tap (not remineralising RODI) , and my plants are not you plants. In other words those variables will have to be adjusted for somehow.

Thank you for your patience!

 

[LFNfan]

Ok, I will have a bash.
One question: do I just add the NH4+ and NO3- mg/l together? Ie 0.298+0.992?
Not sure. Molar masses are quite different.