Macro mix stability

[dw1305]

Hi all,

I was testing the premix at 6dkh but this was inaccurate cuz the CaCO3 had not gone into solution. And when I test tank water at 6dkh it's not offgassed.

Yes that is it, measuring dKH is slightly problematic, because the kits <"measure alkalinity via titration">, rather than the actual amount of bicarbonate (HCO2-) ions. You have another layer of complexity from the added CO2 <"Ph drop & high alkalinity">.

Once the water is in the tank it will be difficult to measure dKH (although you could measure alkalinity, but only when the tank is degassed). Do you have a TDS meter? It doesn't directly measure any of the things that you are interested in, but it will give you an idea of where things are <"Guide to TDS">. I just use a <"conductivity datum for the tanks">, I'm lucky in that I have a consistent hard, low nutrient tap water, which means that I know that the ~600 micro S in the tap water is mainly Ca++ and 2HCO3- ions. I keep soft water fish, so I only add a very small amount of tap to the rain water tanks, and only when the tank water conductivity falls below about 80 microS.

You can calculate the dKH value (and the dGH) in your water change water from the salts addition <"Water Hardness">.

........ you can convert the 137 mg/L CaCO3 value to dKH using: 1dKH = 17.86 mg/L CaCO3 and 137/17.86 = 7.67 dKH.

I'll just do the CaCO3 in the water change water, but 5g = 5000 mg and you have 136 litres of water. 5000 / 136 = 37 and 37 / 17.86 = 2.01 dKH.
What happens to the dKH in the tank depends on a couple of factors:

• How much is converted to CO2 and outgassed when the pH falls and
• how much is utilised by microbial nitrification

A potential third sink is <"any molluscs in the tank">, when they are shell building.

cheers Darrel

 

[_Maq_]

I hope this is still an effective way to get the Ca in there. Possibly i need to re-visit my remin compounds.

Powdered (lab grade) CaCO3 is very useful if you perform complete mineralization from RODI water and want to add some acid neutralizing capacity = alkalinity = dKH. It's because among (bi)carbonates only those of potassium and sodium are easily soluble. Yet we don't want that much potassium or sodium in our tanks!
Incidentally, virtually all commercial re-mineralizers targeted at increasing dKH use these unwelcome (bi)carbonates... and take scandalous money for this trash.

Do you have a TDS meter?

Darrel, would you kindly join me in my effort to unteach people to use TDS units? You know just as well as I do that no meter can measure TDS...

 

[blairgerman]

Hi all,

Yes that is it, measuring dKH is slightly problematic, because the kits <"measure alkalinity via titration">, rather than the actual amount of bicarbonate (HCO2-) ions. You have another layer of complexity from the added CO2 <"Ph drop & high alkalinity">.

Once the water is in the tank it will be difficult to measure dKH (although you could measure alkalinity, but only when the tank is degassed). Do you have a TDS meter? It doesn't directly measure any of the things that you are interested in, but it will give you an idea of where things are <"Guide to TDS">. I just use a <"conductivity datum for the tanks">, I'm lucky in that I have a consistent hard, low nutrient tap water, which means that I know that the ~600 micro S in the tap water is mainly Ca++ and 2HCO3- ions. I keep soft water fish, so I only add a very small amount of tap to the rain water tanks, and only when the tank water conductivity falls below about 80 microS.

You can calculate the dKH value (and the dGH) in your water change water from the salts addition <"Water Hardness">.

I'll just do the CaCO3 in the water change water, but 5g = 5000 mg and you have 136 litres of water. 5000 / 136 = 37 and 37 / 17.86 = 2.01 dKH.
What happens to the dKH in the tank depends on a couple of factors:

• How much is converted to CO2 and outgassed when the pH falls and
• how much is utilised by microbial nitrification

A potential third sink is <"any molluscs in the tank">, when they are shell building.

cheers Darrel

I suspected there's no telling what the reagent in the sera test kit is reacting with. The rams horn shells were deteriorating and I had used this as a loose indicator of a calcium deficiency, not a determinant, but just an observation taken into account. I have been using TDS meter (measures in ppm) just for gross assessment, I should have put that in my tank summary. I had been getting 200-250 consistently per my last log entries about 3 months ago, but per your comment i just measured in tank 450ppm... that's way too high and my tap is 125, which converted to Microsiemen is 200, a 1/3 of yours. I'm defiantly seeing the remin salts are too much, i will discontinue the CaCO3. I've also had iron up to .7ppm target (between gluc and DTPA) for a few months and this has resulted in a noticeable change in black deposits in my pre-filter, not sure it's effect on TDS readings. I have a bad habit of changing to many factors at once and will focus on the carbonates and alkalinity for now. Thanks for all your useful feedback and i'm reading the cited threads now. I always try to do more reading a less asking.

Powdered (lab grade) CaCO3 is very useful if you perform complete mineralization from RODI water and want to add some acid neutralizing capacity = alkalinity = dKH. It's because among (bi)carbonates only those of potassium and sodium are easily soluble. Yet we don't want that much potassium or sodium in our tanks!
Incidentally, virtually all commercial re-mineralizers targeted at increasing dKH use these unwelcome (bi)carbonates... and take scandalous money for this trash.

Darrel, would you kindly join me in my effort to unteach people to use TDS units? You know just as well as I do that no meter can measure TDS...

Whoops! well i'll take my "tds" readings with a grain of salt(s) ! I'll assume there is no conversion of microsiemen to ppm. I went the bicarb route cuz i was shy of sodium and sulfates but i see the mess ive made of alkalinity now. Over a year ago i was using a this gh booster with sulfates... maybe i go back to this...?

 

[blairgerman]

Incidentally, I'm about to get a direct hit from a Cat3 hurricane. Now I'll have to account for the parameters of storm surge water in my tank.

 

[dw1305]

Hi all,

Darrel, would you kindly join me in my effort to unteach people to use TDS units?

I will, and I have tried <"https://www.ukaps.org/forum/threads/tds-tester.67962/page-2#post-673830">.

The rams horn shells were deteriorating and I had used this as a loose indicator of a calcium deficiency, not a determinant, but just an observation taken into account.

That is the <"technique I use">, but I'm not a CO2 user <"https://www.ukaps.org/forum/threads/nerite-snails-in-high-tech.33556/page-3">.

The problem you (and your snails have) is that as soon as your pH dips below pH7 CaCO3 will start to go into solution, with aragonite more soluble than calcite. When the pH rises back above pH7? The CaCO3 <"will precipitate back out">, but not as part of the snails shell. You lose some of the <"Total Inorganic Carbon"> (T(D)IC) as CO2 gas, but you still have all the calcium you started with.

I'll assume there is no conversion of microsiemen to ppm.

Yes there is, it depends on the conversion factor on the meter, but for freshwater 64ppm TDS is really 100 microS.

but per your comment i just measured in tank 450ppm... that's way too high and my tap is 125, which converted to Microsiemen is 200, a 1/3 of yours. I'm defiantly seeing the remin salts are too much, i will discontinue the CaCO3.

Try a bit lower and see what happens.

Over a year ago i was using a this gh booster with sulfates... maybe i go back to this...?

It really depends how you feel about sulphate (SO4---), I'm not too bothered, but I'm adding <"very low levels of nutrients"> to my tanks (including MgSO4.7H2O) and I'm remineralising with tap water (so 1 : 1 dGH : dKH via CaCO3).

...... @Roland has grown a lot of them and can tell you about the <"water parameters and plants he uses">, the water parameters are similar to those recommended by @JamesC at <"James' Planted Tank">.......

The potassium (K) doesn't actually add to the dGH, it is a monovalent ion (K+).

cheers Darrel

 

[blairgerman]

Hi all,

I will, and I have tried <"TDS tester">.

That is the <"technique I use">, but I'm not a CO2 user <"Nerite Snails in high tech">.

The problem you (and your snails have) is that as soon as your pH dips below pH7 CaCO3 will start to go into solution, with aragonite more soluble than calcite. When the pH rises back above pH7? The CaCO3 <"will precipitate back out">, but not as part of the snails shell. You lose some of the <"Total Inorganic Carbon"> (T(D)IC) as CO2 gas, but you still have all the calcium you started with.

Yes there is, it depends on the conversion factor on the meter, but for freshwater 64ppm TDS is really 100 microS.

Try a bit lower and see what happens.

It really depends how you feel about sulphate (SO4---), I'm not too bothered, but I'm adding <"very low levels of nutrients"> to my tanks (including MgSO4.7H2O) and I'm remineralising with tap water (so 1 : 1 dGH : dKH via CaCO3).

The potassium (K) doesn't actually add to the dGH, it is a monovalent ion (K+).

cheers Darrel

A very thoughtful reply with much reading to do, thank you so much for your efforts!