High PH in RO water
- Thread starter Alan
- Start date
Sorry must disagree. Just because you have a high Ph, does not mean you have high alkalinity....the higher the pH the less calcium it can hold...
But why on earth buffer your ro... Dean would love to know....If you were maybe buffering to maintain a lower Ph that would make sense...but this would not be achieved with our convetional bicarb mixtures. ...
If i need to raise calcium i just accelerate evaporation.... Pure water can not posibly have such a high pH...you either have a faulty tds metre or pH metre
Okay maybe i am not explaining myself here. At the moment i am adding CA manually to the tank. The method i use for this is diluting CA chloride into ro water and then dripping the litre of water into the system to raise CA levels. I have had a problem since i moved here that my RO water has a PH of about 8.5 with a TDS reading of 0. Tested by about 4 different TDS meters and 3 different PH meters, now i know it doesn't make sense but that is what it is. Marco and myself have tried all sorts even water softeners.
Anyway the higher PH will cause less CA to dissolve into solution is what i needed to know. Will need an acid to bring it down abit.
CaCl is higly soluble...and ro water will literally disolve anything....i think Marco told me once ...that for this reason ro/di water should not be sipped with your scotch.
When i bumped into you at Northlands the other day you mentioned the use of calcium chloride. At the time i could not remember where i had read another reason for not using it; other than the shift in ionic balance....but i rememberd that evening... In the Zeo guide they twice refer to Acropora species being sensitive to this form of calcium addition ie the change in Cl levels.
When i bumped into you at Northlands the other day you mentioned the use of calcium chloride. At the time i could not remember where i had read another reason for not using it; other than the shift in ionic balance....but i rememberd that evening... In the Zeo guide they twice refer to Acropora species being sensitive to this form of calcium addition ie the change in Cl levels.
Readily avail, but not cheap: calcium polygluconate, but you need lots to raise your ca level......
This does sound odd though.......
Have you tried contacting your water authorities to try and find out what they using to buffer???
Oh, and yes, you are going to have less calcium in your top up water if you were using kalk, but like sunburst said, ca cloride higly solluble.
Are you running a ca reactor???
This does sound odd though.......
Have you tried contacting your water authorities to try and find out what they using to buffer???
Oh, and yes, you are going to have less calcium in your top up water if you were using kalk, but like sunburst said, ca cloride higly solluble.
Are you running a ca reactor???
Where are our mad scientists when you need them?
At a guestimate I would say you should theoretically (In my limited scientific experience ) be able to dissolve adequate CaCl into RO water.
RO water has almost no buffering capabilities so it will not take a lot to push the PH either up or down. Therefor I feel it will not be a problem to dissolve adequate CaCl into RO. IMO you would have to reach NSW levels before saturation occurs.
I have been known to be wrong before though. Won't admit it to the wife though.
At a guestimate I would say you should theoretically (In my limited scientific experience ) be able to dissolve adequate CaCl into RO water.
RO water has almost no buffering capabilities so it will not take a lot to push the PH either up or down. Therefor I feel it will not be a problem to dissolve adequate CaCl into RO. IMO you would have to reach NSW levels before saturation occurs.
I have been known to be wrong before though. Won't admit it to the wife though.
Alan, have you tested the alkalinity of your RO water?
It may have a high pH but zero alkalinity (in RO water it will only take a very little of a pH raising ion like hydroxide to have a major effect due to the lack of buffering capacity of RO water.)
As for your original question, the high pH of Ro water will nto affect its ability to dissolve calcium chloride. This is only applicable in salt water which is already loaded with other ions (chlorides, sulphates, sodium, potassium and bicarbonates) - RO water has a huge capacity to dissolve materials relative to salt water.
It may have a high pH but zero alkalinity (in RO water it will only take a very little of a pH raising ion like hydroxide to have a major effect due to the lack of buffering capacity of RO water.)
As for your original question, the high pH of Ro water will nto affect its ability to dissolve calcium chloride. This is only applicable in salt water which is already loaded with other ions (chlorides, sulphates, sodium, potassium and bicarbonates) - RO water has a huge capacity to dissolve materials relative to salt water.
Another option apart from calcium gluconate to raise calcium without affecting chloride levels is calcium acetate, This is what happens when guys add acetic acid (vinegar) to kalkwasser solutions. This has the added benefit in that acetate can be converted to alkalinity.
For a change...100%
This is what i would do.... Would also provide a carbon source for your bacteria lowering nitrate at the same time.... 36 percent more calcium can be dissolved using the maximum dosing amount ie 12ml vinegar to 1 litre water...howevr the recomended quantity is 3ml to 1 litre saturated kalk. Bingman 1999e/Deelbeek/Sprung....
Slaked lime; calcium hydroxide 12 tsp in 20 litres i think creates a saturated solution. I do not shake rattle or roll.. or stir... 4 tsp in my top up drum (25L) and just let it settle. Twice a week i top up the drum with fresh ro and add another 4tsp. Every second week drum gets rinsed. The vinegar provides the alkalinity in the form of co2 and acetate. As long as the Ph is sitting above 11 i am happy. To much aeration will cause calcium carbonate precipitation. IE NO MIXING
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How much vinegar do you add to the 25L and do you add before or after the kalk? I must say i doubt whether a kalk solution will be able to keep up with the CA demand on my system, we will have to see. Another concern is i already add a source of carbon to the system in the form of Zeostart and wonder if i should cut it back a bit.
Alan, calcium carbonate would be the perfect solution(chemical) to use if only it dissolved!
alan....i have some awesome calcium carbonate.......give me a bell
