DIY Fertilizer Formula Recommendation

[Hanuman]

I decided to do an all-in-one solution (only 500ml) just to test using the same formulation. However a day after I noticed that the mixture had become cloudy. I didn’t see any precipitation at the bottom of the bottle. I did acidify the water prior adding all elements so I am not sure what’s going on.

Ideas?

 

[Zeus.]

I added Excel Fe once and got a cloudy precipitate when my ADA AS had lost its buffering capacity- well that's what I put it down too with my hard water

 

[Hanuman]

I added Excel Fe once and got a cloudy precipitate when my ADA AS had lost its buffering capacity- well that's what I put it down too with my hard water

Flourish iron is gluconate based. I didn’t add any iron gluconate to my solution. By cloudy I meant the fertilizer inside the bottle became cloudy not when adding the fertilizer to the tank.

 

[Zeus.]

Humm.... My answer was a bit vague reading it back 😳 it was meant as a comparison when I posted.
When you say it went cloudy I take it you mean milky white colour?
Never made an all in one as I do just tluse the same micro and macro solutions on low tech tanks as my high tech ones- macros on Sunday and micros on Wednesday.
Did you RO/distilled water for your stock solution or just tap or boiled tap water?

 

[Hanuman]

Humm.... My answer was a bit vague reading it back 😳 it was meant as a comparison when I posted.
When you say it went cloudy I take it you mean milky white colour?
Did you RO/distilled water for your stock solution or just tap or boiled tap water?

Yes cloudy as if milky. Yes I used RO water.

 

[Hanuman]

I checked again and now it does look lile something droped out of solution. Grrr. Is this usable or should I get rid of it?

@dw1305 Recommendations?

 

[Zeus.]

I would do another mix, double checking I had got the correct weight for each salt, easy to get mixed up I have been there mixing up my stock trace and macro mixes 🙄

 

[dw1305]

Hi all,

I checked again and now it does look lile something droped out of solution. Grrr. Is this usable or should I get rid of it? @dw1305 Recommendations?

You could try adding acidifying the solution, or gently warming it, if the milkiness doesn't go back into solution then you will need to make up a new batch.

The problem is that you aren't going to know which ions have combined to form the precipitate.

cheers Darrel

 

[Hanuman]

I would do another mix, double checking I had got the correct weight for each salt, easy to get mixed up I have been there mixing up my stock trace and macro mixes 🙄

Yes maybe I should.

I am pretty sure I didn't mix up stuff. I triple checked the weights and names for each elements. I have the formula printed and I tick each element when done with each. When I am done with one salt I put that salt back in a plastic storage box far away from where I am making my mixes. I shake the solution after adding each salt so that the solution is homogeneous. Not saying mistakes are not possible but in this case I don't feel it's the case. Maybe my protocol is wrong? Here is how I did it:
1 - add RO water to container
2 - add ascorbic acid and potassium sorbate to water. Shook.
3 - checked PH. It was at 4.5.
4 - add macros to water. Shook after each salt was added.
5 - add traces to water. Shook after each trace was added.
6 - checked PH. It was at 4.7.

The solution looked fine the first day. It was clear. Didn't noticed anything strange.

Hi all, You could try adding acidifying the solution, or gently warming it, if the milkiness doesn't go back into solution then you will need to make up a new batch.

The problem is that you aren't going to know which ions have combined to form the precipitate.

cheers Darrel

Ok will try that. Adding extra ascorbic acid?

I am wondering if the acidity of 4.5 was enough to start with. I will check the PH again later today see if it rose.

 

[dw1305]

Hi all,

4 - add macros to water. Shook after each salt was added.
5 - add traces to water. Shook after each trace was added.

Can you keep the macro and micro mixes separate?

I think you are much more likely to have problems with an "all-in-one" mix, because you have the potential for a lot of phosphate etc. compounds, <"which are insoluble">.

cheers Darrel

 

[Hanuman]

Hi all, Can you keep the macro and micro mixes separate?

I think you are much more likely to have problems with an "all-in-one" mix, because you have the potential for a lot of phosphate compounds which are insoluble.

cheers Darrel

Yes I can do that and in fact that is what I did for my previous mix. I just wanted to test the all-in-one because a friend wanted me to make an all-in-one for him.

 

[Zeus.]

Well you take more care than me making your stock solutions 😳

I normally stick container and funnel and scales tare scale add each salt approx rating between than dump the water in, lid on good shake which leaves a clumpy mass of salts leave overnight shake and good to go

The other possible answer is the water could be saturated OFC. Add another 500ml of water if the cloudy appearance goes just add double the dose 😉 ( or remove 250ml then 250ml RO and double the dose OFC)

 

[dw1305]

Hi all,

The other possible answer is the water could be saturated OFC. Add another 500ml of water if the cloudy appearance goes just add double the dose

That is a good suggestion and another option.

There is mention of this is in <"Calling all chemists">.

cheers Darrel

 

[Edvet]

( probably unrelated: i add my salts 3x weekly: i add 3 tsp KNO3,1 tsp KH2PO4 and 1 tsp MgSO4 in a liter hot tap water and dissolve it, the liquid was always clear, i've upped my MgSO4 to 3 tsp and now the liquid is milky always)

 

[Hanuman]

I tried all 3 options. Warming it up, diluting with double the water and adding extra acid. The solution is clearer yet remains cloudy, but that's probably due to the increased water amount. I guess that batch is not good. Not sure what is wrong though. I don't believe the formula I am using is overly saturated. Is it?

Below a video of how the solution was prior trying the above.

 

[Hanuman]

Hi all, Can you keep the macro and micro mixes separate?

Would a solutions of iron + traces be stable or is it better to also separate the iron from the traces?

 

[dw1305]

Hi all,

Warming it up, diluting with double the water and adding extra acid..........I guess that batch is not good. Not sure what is wrong though. I don't believe the formula I am using is overly saturated. Is it?

The problem is probably that the insoluble compound(s) that have formed are insoluble in weak acids, as well as water. Iron (Ferric) phosphate (FePO4) would be my guess, it would be soluble in a strong acid (if you had HCl or similar to hand).

Zinc phosphate (Zn3(PO4)2)(H2O)4) would also be insoluble, but you have too much precipitate for that.

Would a solutions of iron + traces be stable or is it better to also separate the iron from the traces?

I used to keep the iron separate (so I had three solutions, "macro", "micro" and "FeEDTA"), but if you keep it the micro-solution acidified you should be all right.

The main aim is to keep iron solution acidified and away from the orthophosphate (PO4---) & carbonate (HCO3-) ions. The low pH means that the formation of iron hydroxides and carbonates isn't a problem.

cheers Darrel

 

[Hanuman]

Ok thank you Darell. Will have a go with a 2 solutions macro and micros+iron. It's not really for me but for a friend that wants to keep it as simple as possible. I am still using the 3 solutions as you advised some time ago for myself and so far so good.

 

[X3NiTH]

In the video you posted you can see that it looks like paper pulp mixed in with the solution as a suspension, this is Zinc Hydroxide formation. The reason for this reaction is that the starting solution wasn't low enough on the pH scale, pH4.5 is too high, bring it down to pH2-2.5 and the Zinc Hydroxide shouldn't precipitate out and the solution will remain clear. If making an all in one I would make sure the solution is still quite acidic for if and when phosphate gets added at the end.

When I was formulating my traces I used two clear solution commercial mixes as a comparative, the first was Flourish Trace which had a pH of 2.7 and the second was Sera Flore DayDrops which had a pH of 2.15. When it came to the addition of Ferrous Gluconate, the commercial mix I was using had a pH of 3 in the bottle (Microbe-Lift Plants Fe), the powdered 11% FeDTPA I was adding also was tested for pH (made a solution in a separate bottle for pH testing) a mixture at a concentration for dosing at 0.5ml/10L for 0.25mg/L came out at a pH of 2.6 (water used was RO/DI 0TDS).

As a comparative Flourish Comprehensive has a pH of 4.3 in the bottle, I assume the reason for the higher pH is likely due to the humic acid content in the bottle, the Humic Acid based BioCo2 supplement I use has a bottle pH of 8.5, it's addition to a test amount of DIY trace with a pH of 2-2.5 climbs up to about pH4.5 afterwards when added at the correct dosing amounts, this is fairly inline with Flourish Comprehensive. The blackness and opacity of the resultant mixture makes it very hard to detect any precipitation if it has formed (same look and consistency of Flourish Comprehensive), when the bottle gets to the dregs at the end I can detect a slight creaminess to the liquid so there is some precipitation going on but it's very minimal (very consistent with Flourish Comp which does the same thing).

Make small batches to test the reactivity of the resultant solution, when you find a stable mix then you can scale up, I went for broke at the first shot and made 5L of trace that the zinc dropped out of, reacidifying just oxidised the Zinc Hydroxide in the solution making it completely unavailable (went from white paper pulp precipitate to a black dust).

🙂

 

[dw1305]

Hi all,

In the video you posted you can see that it looks like paper pulp mixed in with the solution as a suspension, this is Zinc Hydroxide formation. The reason for this reaction is that the starting solution wasn't low enough on the pH scale, pH4.5 is too high, bring it down to pH2-2.5 and the Zinc Hydroxide shouldn't precipitate out and the solution will remain clear......

......Make small batches to test the reactivity of the resultant solution, when you find a stable mix then you can scale up, I went for broke at the first shot and made 5L of trace that the zinc dropped out of, reacidifying just oxidised the Zinc Hydroxide in the solution making it completely unavailable (went from white paper pulp precipitate to a black dust).

Brilliant, that is a great post and I've learnt something new.

cheers Darrel