GH+KH RO Reminiralzation Product Help.

[Zeus.]

Do you know when the calculator will be released yet

Soon, I would be more definitive, but we have to get it passed off by our experts first also 😬, we are hoping before Christmas 2020 all the same as we are getting down to the finer details ATM.

 

[dw1305]

Hi all,

Good, it also does another level on 'checking' on our calculations as well

Was it potassium carbonate (K2CO3), rather than potassium bicarbonate (KHCO3)? If so it makes the dKH = 1.5 and 40.7 ppm K.

Doing the dGH "long hand" (using the values from <"James' Planted Tank">, and assuming the two salts are the stable hydrates (CaCl.6H2O) and Mg.SO4.7H2O) I get:

Ca = 2.34 dGH and Mg = 2.75 dGH, so 5.1 dGH. When I get a moment I'll go through it properly via the calculations <"in the Krib">.

cheers Darrel

 

[Wookii]

Hi all,

Was it potassium carbonate (K2CO3), rather than potassium bicarbonate (KHCO3)? If so it makes the dKH = 1.5 and 40.7 ppm K.

Doing the dGH "long hand" (using the values from James' Planted Tank, and assuming the two salts are the stable hydrates (CaCl.6H2O) and Mg.SO4.7H2O) I get:

Ca = 2.34 dGH and Mg = 2.75 dGH, so 5.1 dGH. When I get a moment I'll go through it properly via the calculations in the Krib.

cheers Darrel

Good spot Darrel - it's a good job you are on point lol . . . yes, its K2CO3 I'm adding, Potassium Carbonate. https://apcpure.com/product/Potassium_Carbonate_Anhydrous_99_ACS

Edit: I based the dosing for that on the James Planted Tank page, which states:

1.5g NaHCO3 in 25 litres of water = 2 dKH
1.8g KHCO3 in 25 litres of water = 2 dKH
1.2g K2CO3 in 25 litres of water = 2 dKH

So should my 1.8g dose of K2CO3 not yield 2dKH / 1.2 x 1.8 = 3dKH?

 

[dw1305]

Hi all,

So should my 1.8g dose of K2CO3 not yield 2dKH / 1.2 x 1.8 = 3dKH?

I like this checking thing, and it should 3 dKH.

So apologies, that was me using 1.8g = 1 dKH, rather than 1.8g = 2 dKH.

cheers Darrel

 

[Wookii]

Hi all,

Would be my guess.

The TDS (conductivity) reading should be right. It is a linear scale and pretty straightforward. That is why I like conductivity as a metric, it might not be that useful, but it will be accurate.

After that It is going to depend upon what the test kits actually measure. The dKH drop test <"measures alkalinity"> via an <"acid base titration">, and I have no personal experience of their accuracy.

I've no idea how the dGH kit works, but if it produces a white precipitate? It may use soluble dilute sodium hydroxide (NaOH) to <"form insoluble Ca(OH)2 and Mg(OH)2">.

You would also potentially get aluminium and iron hydroxides formed as well, although they wouldn't necessarily be white, and as the solution became <"more alkaline the aluminium ions would go back into solution">.


But you actually know exactly how much dKH and dGH you have in your RO water, because it is the amount you've added, it is your standard. If the test kit numbers you've got are different? It is the test kit that is wrong.

The workings are in <"What do the three....">, derived from Larry Frank's very useful <"the Krib"> article.

cheers Darrel

OK, so back on this one Darrel, I've been reading through some of the links you gave, though most of the real chemistry is beyond me, and the whole KH/alkalinity discussion appears to be Alice's 'rabbit hole', so I don't want to fall down that too far!

After another week of water changes, I'm still consistently measuring a KH (alkalinity) of around double what I'm adding to the RO mix, and a GH around 1.5 times. Having now read around a number of other forums, I've seen a number of other similar experiences when using large amounts of Seiryu stone. Since the whole point of me going to the effort and expense of the RO system, was to maintain soft water for soft water fish species - purely to give them the best possible environment and care, I need to establish a practical way forward, and chalk up (no pun intended lol) the extensive use of stone containing calcium carbonate as a 'schoolboy error' (next time I'll be using lava rock!).

So, at risk of wearing you a little thin on this subject, can I pose some more questions?

1. If the KH measures alkalinity rather than pure carbonate content, do we actually care - from a practical sense - about the quantity of carbonates? What I mean by that is, if the aquarium water is obtaining additional alkalinity from somewhere, in terms of providing a healthy aquarium, do we care what it is comprised of, or simply that it exists? If not, it would seem a practical approach would be to simply cease dosing K2CO3 completely, which should (in theory) mean the aquarium maintains an alkalinity of around 3dKH on its own? Are there any risks in that approach?

2. If we believe that the rock is the main culprit of the increasing GH, Is it safe to assume that the difference in dGH will be appearing mainly if the form of Calcium (I assume there is no practical way to test this)? If so, it would appear that a practical solution would be to reduce the dosing of CaCL2 by half (or more if necessary) to reach the desired dGH?

3. From a fish care perspective, is all this effort worth while - will the fish actually be happier, healthier and longer lived in the softer water? Also, my only reason for trying to maintain a GH of around 7 is so the shrimp have sufficient Calcium in the water column for moulting - is this a valid objective also, or should I just go softer on the GH (perhaps not dosing CaCl2 at all) and supplement with calcium rich foods?

 

[dw1305]

Hi all,

f not, it would seem a practical approach would be to simply cease dosing K2CO3 completely, which should (in theory) mean the aquarium maintains an alkalinity of around 3dKH on its own?

If the KH measures alkalinity rather than pure carbonate content, do we actually care - from a practical sense - about the quantity of carbonates?

If we believe that the rock is the main culprit of the increasing GH, Is it safe to assume that the difference in dGH will be appearing mainly if the form of Calcium (I assume there is no practical way to test this)? If so, it would appear that a practical solution would be to reduce the dosing of CaCL2 by half (or more if necessary) to reach the desired dGH?

If the "extra" dKH is from the dissolution of limestone (CaCO3), then you don't need the potassium carbonate (K2CO3), but you should also have an equal addition of dGH (Ca++) and dKH (2HCO3-) ions.

I might try reducing the calcium chloride hexahydrate (CaCl2.6H2O). In terms of measuring the calcium content of the water unfortunately it is <"Flame photometry, AAS or ICP">. What does the conductivity (TDS) meter say? Is the value rising?

and supplement with calcium rich foods?

Give it a go.

will the fish actually be happier, healthier and longer lived in the softer water?

That is just an unknown. I don't tend to muck about too much with water chemistry, just because I know I'm too lazy to be bothered with it long term. I know that our rain-water varies between about 30 microS and 160 microS, and is usually somewhere around 120 microS mark. I just work from them, it suits soft-water fish, but not black water ones, and it isn't really hard enough for Cherry Shrimps. I have a hard, high quality tap supply, and access to DI water, but my main aim is just to use 100% rainwater.

cheers Darrel

 

[Wookii]

If the "extra" dKH is from the dissolution of limestone (CaCO3), then you don't need the potassium carbonate (K2CO3), but you should also have an equal addition of dGH (Ca++) and dKH (2HCO3-) ions.

Thats the big 'if' though isn't it. Does it matter if the extra dKH (I guess we should really say alkalinity) isn't from CaCO3, and instead is from something else (phosphates, silicate, nitrates etc - as per the James's Planted Tank page). In that case am I still okay to not dose any carbonate?

I might try reducing the calcium chloride hexahydrate (CaCl2.6H2O). In terms of measuring the calcium content of the water unfortunately it is <"Flame photometry, AAS or ICP">. What does the conductivity (TDS) meter say? Is the value rising?

It is yes, the TDS is up to around 250-275ppm, versus a consistent TDS of 200ppm in the RO mix, though again I can't be sure that is CaCO3 of course, and not just because the filter is due a clean etc.

Give it a go.

I probably will, I'm just nervous of losing or causing issues my established Bloody Mary colony.

That is just an unknown. I don't tend to muck about too much with water chemistry, just because I know I'm too lazy to be bothered with it long term. I know that our rain-water varies between about 30 microS and 160 microS, and is usually somewhere around 120 microS mark. I just work from them, it suits soft-water fish, but not black water ones, and it isn't really hard enough for Cherry Shrimps. I have a hard, high quality tap supply, and access to DI water, but my main aim is just to use 100% rainwater.

cheers Darrel

I don't have access to the rainwater - though I appreciate that's a daft thing to say, what I mean is I don't have the facilities/space to store it in sufficient quantities and re-routing downpipes would be traumatic at best, and my tap water is hard which is why I've gone down the RO route. If/when we move house, I do plan to move to rainwater if I can build it in.

Have you not been able to keep Cherry shrimp in your tanks then?

 

[dw1305]

Hi all,

It is yes, the TDS is up to around 250-275ppm, versus a consistent TDS of 200ppm in the RO mix

That sounds pretty definitively it is the rock, and they are Ca++ and HCO3- ions.

though again I can't be sure that is CaCO3 of course, and not just because the filter is due a clean etc.

That is the useful thing with conductivity, it is just a measure of ions.

When that number goes up, you have more ions in solution they haven't been shuffled around, they are new ions. You haven't added any more salts, so it is a salt source in the tank, which is slowly going into solution. Slow dissolution is usually indicative of <"limited solubility in a buffered system">, which is what you have here.

Have you not been able to keep Cherry shrimp in your tanks then?

I kept them for a couple of years successfully, and I used them as a <"supplementary food for the Apistogramma">. I had a more black-water tank at the time (I had some <"Parosphromenus Bintan")"> and that tank was always too soft for any snails or Cherry shrimps. I noticed that my main colony was shrinking one winter, but I didn't think too much about it.

Eventually <"all I saw were very occasional shrimps"> and I noticed that I had very few Red Ramshorn snails left, and the remaining ones I had were all small, white and paper thin. At this point I measured the conductivity and it was about 60 microS.

My shrimp population never recovered, probably because all the remaining ones were male.

cheers Darrel