# DIY Macro Solution Problems



## Donovan (19 Oct 2020)

Good Day everyone!

I'm trying to make a Macro Soultion of the following

6.52 grams KNO3
2.87 grams KH2PO4
18.27 grams K2SO4 
11.65 grams MGSO4
500ml distilled water

I've made a couple of batches trying to dissolve all the salts but once I add the K2SO4 each time It precipitates out of the solution and some of it settles at the bottom of the bottle.
I'm not sure what I'm doing wrong cause I'm following this recipe from someone else. 
I would be really grateful if someone could please help me out. 

Kind Regards 
Donovan


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## Zeus. (19 Oct 2020)

Donovan said:


> but once I add the K2SO4 each time It precipitates out of the solution and some of it settles at the bottom of the bottle.



Which IMO suggests the water your using is already has salts in it, I take it your not using RO water so try boiling eater first let it cool and decanter the water before using it or get some RO water 

the solubility of KSO4 is 111.1grams per litre so you shouldn't be having this ppt


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## Donovan (19 Oct 2020)

Hello Zeus. Thankyou so much for the reply.

I was first using tap water and figured maybe that was the problem but then I switched to distilled water and the problem still persists. 

I checked the TDS of the distilled water I received and its showed me a reading of 1.
I've been at this for the past 1 month and I cannot seem to get this right

Regards 
Donovan


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## Zeus. (19 Oct 2020)

Donovan said:


> 500ml distilled water



oops sorry missed that in initial reply 

Well I normally add 60g of K2SO4 per litre of RO water and no problems with solubility with it, takes a little time to dissolve but it does. So initially I would look at the purity of the K2SO4 which your using.

Here a list of the solubilities of the salts your using which is 75% of their actual solubilities


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## Donovan (19 Oct 2020)

Thanks for the reply.

Maybe I should try and get K2SO4 from a different supplier and then do the mixture again.
In the meantime can I filter out the sediments from the bottom and use the fertilizer?  Would it change the values by too much? 

Regards 
Donovan


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## Zeus. (19 Oct 2020)

Donovan said:


> In the meantime can I filter out the sediments from the bottom and use the fertilizer? Would it change the values by too much?



Depends on how much ppt out , you can just dry dose the salt direct each week in the tank


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## Donovan (19 Oct 2020)

Hello, 
I could dry dose as you say but alot of people have said it better to dose on a daily basis than just once a week(not sure if its true) and dosing day salts everyday would be quite annoying.
Also I like having a solution pre made cause it's much easier and looks alot quit better than having the dry salts kept there haha.

Regards
Donovan


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## papa_c (19 Oct 2020)

Interesting that I have also experienced this,  I now disolve k2so4 separately from all other salts and then mix the two solutions together and don't get the any precipitation.

Never found out what causes it and I was never near the solubility limits.


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## Basviola (19 Oct 2020)

Hey papa_c

I use the same salts for my micro. Different supplier ofcourse. I can dissolve a lot more of the salts. So I would also suggest trying a different supplier. 

Roughly calculated what you would add to 1000ml water to compare it with the macro recipe I am using right now.

Would be very grateful if you could tell me your plan/reasons for adding the salts in these amounts? Also your dosing volume?
Trying to understand all this DIY fert dosing...

Your recipe 
13 grams KNO3 
5,7  grams KH2PO4
36,5 grams K2SO4
23 grams MGSO4
1000ml distilled water

My recipe
*KNO3 62,8 g
KH2PO4 9,2 g
K2SO4 68,8 g
MgSO4 108,4 g
1000 ml boiled tap water*


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## X3NiTH (19 Oct 2020)

The precipitation you are seeing will likely be a variant of Magnesium Phosphate. If there is ammonia contamination present in any of the salts whether it’s derived from ammonium phosphate or ammonium nitrate when it hits solution and there is magnesium sulphate in the receiving water there is a chance for precipitation of insoluble MAP (magnesium ammonium phosphate). You can try to acidify your water to a low pH using citric acid (half gram in a litre of water should be enough) to help mitigate the effect. Ensure full solubility of each salt in the bottle before adding the next salt to the mix, if you keep seeing precipitation then you have a contaminated batch of salts and you need to test to find the culprit.

Heres a solubility rules table -


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## Donovan (20 Oct 2020)

Hello everyone. 
Thanks for all the replies. 
Like @papa_c spoke about dissolving it separately and then adding it to the solution, well I've done that aswell and I still get the precipitate. It only happens with the K2SO4. I've added all the other salts and the solution remains clear. But once the K2SO4 is added the solution becomes slightly milky and slightly frothy and maybe after a few mins it starts to precipitate and settle at the bottom.
I've just placed an order with a new supplier and I'm hoping the problem doesn't persists.
I was experimenting with a few other salts like K3PO4 and MGN03 and I've realized once you add the above two together the water gets completely milky. 
@X3NiTH  I think you are completely right. It could be a variant of Magnesium Phosphate.
I've also tried adding about half a gram of ascorbic acid to the water prior to adding the salts and it was all good until I put in the K2SO4. As @Zeus suggested I think it could be a problem with the salt. 
I'm really new at this. Sorry if these replies are quite stupid. 
I've had these plants tanks for about 8 months now and it's getting quite expensive to buy a bunch of premium fertilizers. 

Regards 
Donovan


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## Zeus. (20 Oct 2020)

X3NiTH said:


> You can try to acidify your water to a low pH using citric acid (half gram in a litre of water should be enough) to help mitigate the effect.



I suppose adding Ascorbic acid (0.5g/l) and Potassium Sorbate (0.4g/l) to help prevent mold and reduce the interactions PO4 and Fe, could/is also helping the K2SO4 to dissolve also- might just try adding some of my K2SO4 to 500ml of RO water


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## Donovan (21 Oct 2020)

Hello everyone!
While we're on the topic of fertilizer does any have an idea to make a micro solution from scratch. 
I'm actually from India and alot of what we get here isnt the greatest. 
Any replies would be really appreciated

Thank
Regards 
Donovan


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## Zeus. (21 Oct 2020)

Donovan said:


> While we're on the topic of fertilizer does any have an idea to make a micro solution from scratch.



Yes, myself and @Hanuman are working on a DIY fert calculator, with help and guidance from some of the experts here and the Barr Report, the DIY trace section is the next section we are working on. The Program is excel based and it basically works out all the yields from grams of salts or from target concentrations and jives the grams of what salts to add. You can compare your yields with commercial ferts, AOI and traces mixes


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## Donovan (21 Oct 2020)

Wow. That is really amazing. 
This forum is truly lovely.
All the best on the calculator.

Regards
Donovan


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## Donovan (29 Oct 2020)

Hey guys. 
Just thought I'd give an update. So I got another batch of K2SO4 for a different supplier and there seems to be no problem at all now. I've even doubled the dosage and the solution remains clear.
Thankyou everyone for the advice. 
Ps - @Zeus. Eagerly waiting for the new calculator. 😁. Cant wait to try making a micro fert aswell. 

Regards
Donovan


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## Donovan (1 Nov 2020)

Hello again,
@Zeus. Have you ever tried using tri potassium phosphate instead of mono potassium phosphate. 
I've used it to make an alternate solution but the water turns completely milky. Does this happen with you'll aswell? 
If anyone has made a solution using the K3PO4 can you please help me out. 

Regards
Donovan


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## Zeus. (1 Nov 2020)

Donovan said:


> Hello again,
> @Zeus. Have you ever tried using tri potassium phosphate instead of mono potassium phosphate.
> I've used it to make an alternate solution but the water turns completely milky. Does this happen with you'll aswell?
> If anyone has made a solution using the K3PO4 can you please help me out.
> ...


No I haven't used it and we haven't added it to the range of salts you can use in the calculator, we went through all the possible salts that could be used and if it wasn't easily available to purchase we didn't add them. Seems strange that its gone milky as that suggests it hasn't completely dissolved and K3PO4 has a solubility of of 90g/100ml, where as KHPO4 has a solubility of 26g/100ml.
@X3NiTH my have the answer, however the simple answer my be that the salt you have may not be pure K3PO4 and the other salt 'X' which is present just isn't as soluble as the K3PO4 so salt 'X' results in a milky solution when the compound is added to water.
Where did you get you K3PO4 from ? as I didn't get any hits for sellers when I google it


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## dw1305 (1 Nov 2020)

Hi all,


Donovan said:


> Have you ever tried using tri potassium phosphate


I wonder if it isn't a pure salt, but either <"di-potassium, or potassium di-hydrogen, phosphate"> mixed with <"triple super phosphate"> (Ca(H₂PO₄)₂ .H₂O)?

cheers Darrel


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## Donovan (1 Nov 2020)

Hey guys
@Zeus.  I managed to get it from a friend who is one of the distributors of chemicals and he lives near me. 
However I just want to confirm if you think it's better to use the K3PO4 or just stick to the KH2PO4.?
I will again try to procure it from another seller and try the formula again. 
Because using K3PO4 reduces the amount of sulfur added with the K2SO4. 
Again I'm really sorry if this is all simple to you all but I'm really new at all this😁.
Thanks for all the replies. 
Regards
Donovan


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## Zeus. (1 Nov 2020)

Donovan said:


> Hey guys
> @Zeus.  I managed to get it from a friend who is one of the distributors of chemicals and he lives near me.
> However I just want to confirm if you think it's better to use the K3PO4 or just stick to the KH2PO4.?
> I will again try to procure it from another seller and try the formula again.
> ...


If the K3PO4 wasn't giving the ppt I would say its fine , however the ppt surgests IMO is impure. If we knew the impurity% or the K3PO4% of the salt was we could work with it. With it having a ppt ( we/you could decanter the soluble salt) the actual [K] and [PO4] will be less than you think, so A little more K3PO4 may be needed (if require). The beauty of using RO water is we know what's in the water as we have added it.
I would say using KHPO4 is better for most folk as it is easy to get hold off.
I don't personally have any issues with high SO4 levels as with my very hard tap water I dread to think how much SO4 s actually in the tap water, so I just accept it as it is as without going down the RO/rainwater route I have little choice ATM.
If/when I was using RO water I would use KCL and K2SO4 50:50 to help reduce the high [SO4].

Never apologize for asking a question, even if may seem simple/stupid to others


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## Donovan (1 Nov 2020)

@Zeus.  Thankyou for the reply.
Maybe like the batch of K2SO4 this batch of the K3PO4 is bad aswell. 
However if I get a better batch I may try to make one with it. 
I've bought alot of distilled water which I got really cheap so I have been using that.
If you add KCL and K2SO4 in a 50:50 ratio wouldn't the CL build up alot over time? 
When I made my first batch i added K3PO4 and MgNO3 and this made the water completely milky. I mean it literally looked like milk. 
Thanks for the replies
Regards
Donovan


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## Sammy Islam (1 Nov 2020)

I always have problems with dissolving salts too, always seem to have a little bit of white powder at the bottom. I never thought to change k2so4 supplier, i currently use aquaplant care salts. 
https://aquaplantscare.uk/shop/aquatic-plants-fertiliser/k2so4/

I make a watered down mix too: 
1000ml DI - 80ml doses
KNO3 22g
KH2PO4  5g 
K2SO4 20g


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## Zeus. (1 Nov 2020)

Donovan said:


> If you add KCL and K2SO4 in a 50:50 ratio wouldn't the CL build up alot over time?


Yes it would build up, however it would be limited by the weekly WC



Donovan said:


> When I made my first batch i added K3PO4 and MgNO3 and this made the water completely milky. I mean it literally looked like milk.



I take it you was using the MgNO3.6H20 which I believe is pretty soluble as well (can ne tricky to get data on as well), but to the ppt when mixing 'I dunno' @X3NiTH may be able to enlighten us on that mix.



Sammy Islam said:


> I always have problems with dissolving salts too, always seem to have a little bit of white powder at the bottom. I never thought to change k2so4 supplier, i currently use aquaplant care salts.
> https://aquaplantscare.uk/shop/aquatic-plants-fertiliser/k2so4/
> 
> I make a watered down mix too:
> ...


again seems strange if the salt are pure




But if you mix your fert let it settle and decanter the clear liquid and use that then just watch your plants, if no signs of deficiencies, its a winner.

The calculator is a useful tool, but it doesn't replace watching your plants. Once you diagnosis a deficiency the calculator helps again as you can then increase the weekly dosing of the deficient element


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## X3NiTH (4 Nov 2020)

If you are having precipitation where you shouldn’t it will likely be due to a compound that’s either there by accident or as part of the manufacturing process for the salt in question. If the resultant mixture has Charge Imbalance then depending on pH and temperature multiple different compounds can form and depending on the solubility rules can precipitate out of solution, in pure water alone oxides and hydroxides can form and even carbonates if the receiving solution is allowed dissolved atmospheric co2 in it.

Pourbaix diagrams are pretty excellent at conveying this information

Water -




CO2 -




Nitrogen -



Some of the Micro Elements -



This last one shows that things can be a little different depending on the dilution of the sample.

At the end of the day if the mixture is built using compatible 99% pure salts and the 1% impurity forms a precipitatate then you are only losing a tiny amount of the total concentration so not worth even worrying, at less than 90% purity I would look for better. You can work out the percentage impurity of your salts by filtering off and drying the precipitate then weighing it to see how much you lost, (not really worth it unless your OCD).

Not sure I’ve been much help.


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## Donovan (29 Nov 2020)

Hello everyone,
@X3NiTH  extremely sorry for such a late reply. 
Luckily I dont have OCD and that process looks to be very tedious so I wont go in for that. Haha.
However I solved the problem with the K2SO4 with a different supplier but I'm still having problems with the K2HPO4.
I sourced the K2HPO4 for a good supplier which says purity 99% and once again when I mix it with the magnesium sulphate or even magnesium nitrate it causes the liquid to become milky. 
I get this same effect with the K3PO4 so I'm not really sure what the problem is. 
This does not happen when I use just KH2PO4 and the KH2PO4 has a purity of just 98%.
Has anyone else faced this same problem or are the salts I'm sourcing just bad. 

Regards 
Donovan


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## X3NiTH (29 Nov 2020)

I’ve posted on another thread recently where I mention the precipitation conditions for Potassium Magnesium Phosphate, I went and dug deeper to quantify what precipitation reactions happen with phosphate and Magnesium and I was unsure whether Magnesium had to be at saturation point in the water for precipitation to occur but from your description this doesn’t appear to be the case, the conditions for the above to form is that the solution will be above neutral pH and that the Potassium concentration exceeds the Phosphate concentration, the Phosphate concentration will be 3mM (miliMolar) or greater. 4.3g of KH2PO4 added to 1L of water is a 1mM solution (12.9g/L = 3mM). You don’t appear to be exceeding this condition but if you are adding all the salts together and then adding the water and it is above pH7 you will exceed these conditions as the salts dissolve in close proximity and as such precipitate will form. 

Try to ensure your receiving water is void of any potential conflicting elements (0ppm TDS preferably) and acidify the water before adding the salts and dissolve fully the Phosphate first before adding the other elements (use the KH2PO4 as it reduces the overall K as you definitely have more K than PO4 in the recipe).

You could reduce the overall concentration of elements in solution and decrease the chance of precipitation by making a more dilute solution that you dose more of to the tank to reach your target levels.


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## Donovan (30 Nov 2020)

Hello @X3NiTH 
Thankyou for the reply.
I'm actually using distilled water so I don't have a problem with the TDS.
Also this perception only happens when I'm using the K2HPO4 or the K3PO4. 
I dont not get any precipitate while using the KH2PO4.
In a 500ml container I'm adding 
17.94 gms KNo3
7.89 gms K2HPO4 
30.42 gms MGSO4.7H2O
12.01 gms KCL 
20.72 gms K2SO4

I haven't acidify the solution prior to adding the salts however I do add one at a time and make sure its dissolved before adding the next salt. 
I had mixed all the other salts and the last one was the MGSO4.7H2O and once I added this the whole solution turned Milky. 
Maybe it did reach the saturation point.
I could maybe increase the KCL as it has a higher dissolving capacity than K2SO4 but I'm worried about increasing the CL concentration in the water. 
Also I'm trying to keep it at 5ml per 100L cause I need the solution to last a but longer as i wont be at home for 4 months and my dad wont be able to figure the fertilizer calculations. 
However as per the above mentioned quantities if you feel its not possible then I think I'll just have to make a very large batch and store that. 
Regards
Donovan


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## Wookii (30 Nov 2020)

Donovan said:


> Hello @X3NiTH
> Thankyou for the reply.
> I'm actually using distilled water so I don't have a problem with the TDS.
> Also this perception only happens when I'm using the K2HPO4 or the K3PO4.
> ...



Sorry if I'm stating the obvious, but if you're having solubility issues, why not just halve your salts per 500ml, double your dose to 10ml, and mix up two dosing containers instead of one, so you have enough to cover the period you are away?

EDIT: Or you could get a 1litre dosing bottle instead: eBay


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## Donovan (30 Nov 2020)

Hello @Wookii 
It isnt a solubility problem. 
Actually I'm having a problem with mixing the magnesium sulphate with K2HPO4 or K3PO4.
I get a precipitation everytime I mix the MGSO4.7H2O with K2HPO4 or K3PO4. But this same issue doesnt arise when using KH2PO4. 
So I wanted to know if anyone else has the same trouble. 

Regards
Donovan


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## Zeus. (30 Nov 2020)

Donovan said:


> It isnt a solubility problem.
> Actually I'm having a problem with mixing the magnesium sulphate with K2HPO4 or K3PO4.
> I get a precipitation everytime I mix the MGSO4.7H2O with K2HPO4 or K3PO4. But this same issue doesnt arise when using KH2PO4.



KHPO4 isnt as soluble as K2HPO4 or K3PO4 by factor of x4 so it doesn't initially point to a solubility issue IMO ( but I am not a chemist), points more to a interaction of the salts present. Is there a reason why you haven't added Ascorbic acid 1.0g/l and Potassium Sorbate 0.4g/l ?


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## Donovan (30 Nov 2020)

Hello @Zeus. 
Well I read on one of the posts that it isnt really required for the Macro solution. 
However I will give it a try tomorrow and see if lowering the PH of the solution prior to adding the salts does make a difference.
I did a small test today with all the chemicals mixed separately in different containers and again there is no precipitation while using the KH2PO4 with other salts like K2SO4,KCL,MGSO4.7H2O,KNO3.
But again while using the K2HPO4 and the K3PO4 I get a milky solution. 
The precipitate that occurs while using the K3PO4 is really thick and almost looks like glue settling to the bottom of the container. 
All the salts are lab grade so I'm not sure what's going wrong. 
Will trying the Ascorbic Acid tomorrow and hopefully it all goes well. 

Regards
Donovan


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## Zeus. (30 Nov 2020)

It doesn't take much to shift the equilibrium and before you know it you have a ppt, But you say it's like glue !!! which doesn't sound like a ppt to me.
I have always added the Ascorbic acid 1.0g/l and Potassium Sorbate 0.4g/l since I got mould in my first batch just to keep the 'fungi' in check. I was making 5 litre batches at first which lasted months, I do try to only mix 6 to 8 weeks worth nowadays


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## Donovan (1 Dec 2020)

Hello
I'll try sending you a picture if it happens again after adding the ascorbic acid and potassium sorbate. 
I'm sorry if I put that wrong about the glue. It's not sticky its it's just really thick and kind of heavy the precipitate which kind of looks like when you put a little glue into the water. 
I will be making a batch now and hopefully it all goes well. 
Thank you all for the hell. 
Will let you'll know how it goes.😁
Regards
Donovan


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## Donovan (1 Dec 2020)

Hello everyone!
So I even tried adding ascorbic acid and well it still results in a precipitation.
I've attached the pictures below while using the K3PO4 and K2HPO4.
I also tried making the solution with KH2PO4 and the soultion remained absolutely clear. 
The K2HPO4 and K3PO4 both have a higher purity grade than the KH2PO4 but they both cause a precipitation. 
I'm guessing I need to just get rid of the other two and just use the KH2PO4.
Even while using the same elements the reaction is completely different. 

Regards
Donovan


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## ian_m (1 Dec 2020)

Right'o stretching my memory way back when investigating EI dosing years ago (2011 ?), why us fish peeps don't use tri-potassium and di-potassium phosphate, but stick to mono-potassium phosphate.

Basically the tri & di potassium phosphate have an issue to do with polymerisation under certain conditions and precipitate out of solution as polyphosphates especially under low pH situations. The polyphosphate is described as looking like "Elmers glue", which is US name for PVA glue. This matches what you are seeing.

Mono-potassium phosphate does not do this.

So yes you can dose, di & tri potassium phosphate but must be dosed separately to prevent polymerisation. Not sure what happens once in the tank, especially with low pH if using CO2, probably be OK as quite dilute.

In the end, I think mono-potassium phosphate is reasonably cheap, is one of the lower doses use in EI, so just dose this. Job done.


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## Donovan (1 Dec 2020)

Hello @ian_m 
Thankyou for the reply. 
Like you said I'll just stick to mono potassium phosphate. 
The only reason I tried to use the other two were to cut down the usage of K2SO4 and reduce the sulfur content building up in the aquarium. 
How it looks to be too troublesome to use the other two. 
Thankyou again. 

Regards
Donovan


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## Zeus. (1 Dec 2020)

ian_m said:


> Right'o stretching my memory way back when investigating EI dosing years ago (2011 ?), why us fish peeps don't use tri-potassium and di-potassium phosphate, but stick to mono-potassium phosphate.
> 
> Basically the tri & di potassium phosphate have an issue to do with polymerisation under certain conditions and precipitate out of solution as polyphosphates especially under low pH situations. The polyphosphate is described as looking like "Elmers glue", which is US name for PVA glue. This matches what you are seeing.
> 
> ...


Thanks for that Ian 
and thats the reason why myself and @Hanuman decided not to add K2HPO4 and K3PO4  to the fert calculator 😇 or it is now 😂


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## ian_m (1 Dec 2020)

Potassium phosphate crystal...

You could always use the phosphate to grow a crystal...


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## Donovan (1 Dec 2020)

@ian_m 
Grow a crystal???😯😯


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## Zeus. (1 Dec 2020)

Donovan said:


> @ian_m
> Grow a crystal???😯😯



If you use the gluppy PO4 mix on your tank you might have a crystal tank scape


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## X3NiTH (1 Dec 2020)

I would stick to KH2PO4 and still suggest making the mixture more dilute, 5ml/100L is really concentrate, 20ml/100L would be better.

If you need more K in the tank dose the Sulphate and Chloride at waterchange as remineralisation instead of trying to cram it all into one bottle.


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## Zeus. (1 Dec 2020)

X3NiTH said:


> View attachment 157220
> 
> I would stick to KH2PO4 and still suggest making the mixture more dilute, 5ml/100L is really concentrate, 20ml/100L would be better.
> 
> If you need more K in the tank dose the Sulphate and Chloride at waterchange as remineralisation instead of trying to cram it all into one bottle.


With Mg3(SO4)2 having covalent bonding hence the change solubility we was expecting form the native salts and its resultant salts thixotropic properties of the reactant ie gluppy.

Always good when we can fit the science with what we see/experiance


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## Donovan (1 Dec 2020)

Hello, 
@Zeus.  I'm sorry I really dont understand much of what you wrote there but I will definitely try and learn some more about it. Thankyou for helping out so much.
@X3NiTH  Thankyou for all the help and the time you've spent on getting the answers. Really appreciate it. 
I have a tank which is 300L and hence was trying to make a concentrated dose so I dont have to dose much(dosing 15ml sounded pretty decent to me at that time). However I will take you're advice and make a leaner dose and just make a bigger batch.
Just out of curiosity, would it really be a problem dosing such a concentrated solution? 
Dosing the sulphate and chlorides after a water change is an option but I'm quite worried what would happen if the CL is a bit much for the livestock. Will try and see what happens. 
I think it's best to keep exploring and finding out better ways to get things done. 
Thankyou again everyone.
Regards
Donovan


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## Zeus. (1 Dec 2020)

I have always tried to make weker solutions, as it avoids the pitfalls of solubility and acts as a 'pseudo' tank top-up as well, In my 500l I dose 100ml a day and in 50l I dose 10ml a day, nice round numbers which make it dead easy to increase/decrease dose by any percentage from baseline and back again dead easy


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## X3NiTH (1 Dec 2020)

Making a concentrate is only problematical if you have reactions in the bottle that may make some elements form insoluble compounds thus decreasing the efficacy of the resulting concentrate. Dosing a concentrate is only problematical for plants and animals if they come into contact with it in concentration before it has a chance to fully disperse throughout the water column.

Whether your dosing your Sulphates and Chlorides in one go or dosed sequentially over the week makes no difference you will still have an accumulated amount totalling near to what it would be dosed in one go. Dosing a fixed amount at waterchange as remineralisation allows you to start with a maxima that will then be depleted over time but never enough for the plants to have a shortfall and the water chemistry stays more stable from week to week through remineralised water changes.


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## Donovan (2 Dec 2020)

Hello,
I will definitely make a weaker solution as you'll suggested. It has alot of advantages over making a concentrated mix. 
In regard to dosing the CL at one go, the only thing that worries me if it's too much for the fish at once. Spreading it over a few days seems better to me but I will definitely give it a try as well.
Does anyone know what's the max concentration of CL that the fish can take ? 

Regards
Donovan


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## X3NiTH (2 Dec 2020)

Donovan said:


> Does anyone know what's the max concentration of CL that the fish can take ?



For Chloride (Cl-), many magnitudes more than you would ever need to dose to a tank to increase the level of an associated element to the satisfaction of plants.

Here’s an extreme example from a study in the US - ACUTE TOXICITY OF CHLORIDES, SULFATES, AND TOTAL DISSOLVED SOLIDS
TO SOME FISHES IN ILLINOIS

Don’t be confusing Chloride Cl- with Chlorine Cl.


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## Donovan (2 Dec 2020)

Hello @X3NiTH 
Thankyou for that. 
Looks like the 6ppm I've added to the tank is nothing compared to what they can take. 
I think I will do as you suggested and dose it after water change and keep the tank more stable. 
Thankyou again for all the advice.

Cheers
Donovan


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## Oldguy (2 Dec 2020)

Donovan said:


> However I just want to confirm if you think it's better to use the K3PO4 or just stick to the KH2PO4.?


K3PO4 is a strong base and will increase your pH.  Most use KH2PO4 because it has a smaller impact on pH.

Holes in plant leaves may be caused by too high a light level/too long a photo period for CO2 & nutrient distribution/dosing levels. Just a thought.


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## ian_m (3 Dec 2020)

Oldguy said:


> Holes in plant leaves may be caused by too high a light level/too long a photo period for CO2 & nutrient distribution/dosing levels. Just a thought.


Holes in leaves can also be caused by potassium shortage. Wonder if due to dosing di-potassium and tri-potassium phosphate the potassium falls out of solution and become not available for plant use ?


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## dw1305 (3 Dec 2020)

Hi all, 


ian_m said:


> Wonder if due to dosing di-potassium and tri-potassium phosphate the potassium falls out of solution and become not available for plant use ?


I'm pretty sure that potassium (K+) is always plant available, just because all the compounds of alkali (group 1) metals are soluble.




cheers Darrel


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## Dani7 (13 Dec 2020)

.


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## Dani7 (13 Dec 2020)

X3NiTH said:


> For Chloride (Cl-), many magnitudes more than you would ever need to dose to a tank to increase the level of an associated element to the satisfaction of plants.
> 
> Here’s an extreme example from a study in the US - ACUTE TOXICITY OF CHLORIDES, SULFATES, AND TOTAL DISSOLVED SOLIDS
> TO SOME FISHES IN ILLINOIS
> ...


Hi @X3NiTH , do you have any links for information on proper Chloride (Cl-) levels in a planted aquarium or what levels are toxic to plants?


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## X3NiTH (13 Dec 2020)

Not specifically sorry, I don’t have access to the papers behind paywalls relating to Chloride toxicity and aquatic plants but there are plenty of free to view papers on terrestrial plants and toxicity when searching ‘Chloride Salt and Plant Nutrition’.

I can say however that there are no proper Chloride levels in a planted aquarium because the environment is entirely artificial to a large degree and the addition or removal of salts to reach a desired level will be completely dependant on the source water (Tap, RO  or RainWater) and available/cheapest salts.

If I were to remineralise 0TDS water to say 20dGH with Calcium and Magnesium Chlorides at a ratio of around 3:1 Ca:Mg then it only represents about 250ppm of Chloride in the water, this is an extreme example it would be a rare situation to need to remineralise to that degree and I wouldn’t do it this manner. However I have remineralised regularly to 6dGh using Chloride derived Magnesium and Calcium salts in the form of SaltyShrimpGH+ and been very successful at growing plants in this environment (others have also) using EI levels of nutrition.

As to what levels are safe for Chloride and plants appears to be tied with Nitrate, as long as there is enough Nitrate to conduct molecular transportation within the plant to efflux excess Chloride then the plant will thrive, if not then the plant will store excess Chloride in the tissues  resulting in toxicity issues and leaf damage chlorosis - necrosis.

As to what ratio of NO3:Cl is beneficial I don’t know but they are both antagonistic to each other according to Mulders chart so more of one element will limit the uptake of the other. All things being equal 1:1 wouldn’t be out of the question but certainly not for remineralisation in extreme to 20dGH in Chlorides because 250ppm NO3 wouldn’t be beneficial.


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