Seachem Purigen Head Scratcher

[MichaelJ]

Hi all,

@John q there isn't a specific thread, as such, but the <"solubility rules chart"> (below) is linked into <"numerous threads">.

View attachment 205632

cheers Darrel

To me darrel that chart makes perfect sense, even with my limited knowledge.

Darrel and John, I like the solubility chart as well, but it should come with a big disclaimer that says that it is not taking acidity of the target solution into account - neither the size of the body of water it will eventually mix into. For instance, Calcium Carbonate (CaCO3) is pretty much insoluble in a small body of water at neutral (pH 7) - something like 0.013g/L at 25C. However, in acidic water say pH 6.2-6.5 it's actually quite soluble (as in usable) especially when considering the low KH levels we normally would target. Of course, the caveat here is that when mixing a stock or pre-batch solutions you're not going to get any solubility unless the pH is very , very low - very acidic, and I personally wouldn't recommend beginners making such a solution.

I am using both CaCO3 (Calcium Carbonate) and CaSO4 (Calcium Sulphate) - both of which are labeled insoluble - that I mix into my WC water.

I would like to take this chart and make it pertinent to our specific application - usually being soft(er) water tanks. Of course, you are (usually) not going to bother about adding CaCO3 or CaSO4 if your using straight tap water.

And btw. @John q, as it applies to running a healthy and prosperous planted tank (actually two tanks) - which is the high order bit on a planted aquarium forum, you know much more about this stuff than you give yourself credit for,

Cheers,
Michael

 

[MichaelJ]

However... for a noob, or somebody that was kissing the boys/girls behind the bike sheds rather than learning

I did both! ... but I was preoccupied with a different kind of chemistry

Cheers,
Michael

 

[John q]

And btw. @John q, as it applies to running a healthy and prosperous planted tank (actually two tanks) - which is the high order bit on a planted aquarium forum, you know much more about this stuff than you give yourself credit for,

My dear friend, I am simply a shrinking violet, whom owes anything I've learnt to this forum.

 

[plantnoobdude]

😃👍


aaaand you lost me 😬 😅

I really think you nerds (begging your pardon😘) overestimate seriously how much chemistry knowledge people have.

It really needs to be super simple and in plain English for it to be understandable to most people.
And there sure are a lot more of "most people" than there are Maq's and Darrel's 😁

I will try to start working on some kind of general guide for this soon, hopefully it will be acceptable to all after some feedback, despite my relatively DIY chemistry knowledge 💪🙂

Electronegativity, in short is how reactive a given atom is and how easy it can share electrons in a molecule.

 

[Hufsa]

Electronegativity

 

[MichaelJ]

Electronegativity, in short is how reactive a given atom is and how easy it can share electrons in a molecule.
View attachment 205638

Now that you told me this, how will it help my Crypts then? 😉

Cheers,
Michael

 

[MichaelJ]

Well, I'll try to provide simplified guide:
(1) On the side of cations, we can rank them according to their electronegativity: K < Na < Ca < Mg << Mn < Zn < Fe < Cu.
(2) On the side of anions, relative strength of acids is instructive: HNO3 > HCl > H2SO4 >> H3PO4 >> H2CO3.
Now, if you blend salts of above listed cations and anions, cations with lowest electronegativity will pair with strongest acids and push the other cations to the weaker acids. An example:
Blending K2CO3 with MgSO4. Both well-soluble. Potassium will 'occupy' position with sulfate anion and 'push' magnesium towards carbonate anion. As a result, MgCO3 will precipitate (see Darrel's chart above).
(I beg all chemists for pardon.)

 

[dw1305]

Hi all,

I would like to take this chart and make it pertinent to our specific application - usually being soft(er) water tanks. Of course, you are (usually) not going to bother about adding CaCO3 or CaSO4 if your using straight tap water.

You could link the solubility values in (from Wikipedia etc), but you would still need to take into account the <"total solubility limit"> and the <"common ion effect">.

Personally I use <"dry dosing"> unless it is a <"horticultural fertiliser"> and designed to be soluble. Using dry dosing means that <"slightly soluble"> isn't an issue, because you have a small weight of salt in a huge volume of water.

cheers Darrel

 

[Hufsa]

I will try to start working on some kind of general guide for this soon, hopefully it will be acceptable to all after some feedback, despite my relatively DIY chemistry knowledge 💪🙂

Im just posting to let you guys know that I havent forgotten about this 🙂
Summer is usually a pretty bad time for me health wise, the heat just seems to sap away the little energy I have, and ive been dealing with some bad fatigue lately.
But the guide is still on my list and I will try to get it done sooner rather than later 😊