Maintaining Calcium and Alkalinity

Alan said:
Right finally got this down to a "T". My alk and Ca additions without my CArx running are the following:
3tsp sodium bicarb + 1tsp sodium carbonate [mixed together] per day gives me 8dkh
8tsp ca chloride + 2tsp kalk slurry[added separately] per day gives me a ca of 390
For Mg i use Epsom salts as needed, about 200g pm, readings at 1200ppm
PH is stable at a min of 8.25 and a max of 8.30, my sg is 1.025 with a refractometer.
Total cost of additives per month is about R120.00
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Just a slight concern from my side Alan and that is the amounts of sulphate you will be adding via the epsom salts.
Preferably use magnesium chloride with a little epsoms ie. for every ten grams MgCl2 , one gram MgSo4, this will be more relative to NSW.
Otherwise, cool, glad its all working out for you
 
Thanks Midas, will order some. Will the chloride in the calcium chloride not balance out the sulphate though? I have cut the addition of calcium chloride by using kalk slurry and was hoping to reach a balance there.
 
Are you using sodium bicarb as well to buffer? If so then the sodium will, in the presence of chloride from the calcium chloride, increase your salinity a tiny amount but i`d still rather use mostly magnesium chloride.
 
Are you using sodium bicarb as well to buffer? If so then the sodium will, in the presence of chloride from the calcium chloride, increase your salinity a tiny amount
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How much of an increase in salinity can i expect, would it be something to keep an eye on?
 
Alan said:
How much of an increase in salinity can i expect, would it be something to keep an eye on?
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If you are constantly monitoring your SG and adjusting as necessary with RO you won't have a problem.

As a guide though each kg of Calcium chloride (anhydrous) will add about 640g of chloride, and each kg of sodium bicarbonate (anhydrous) will add about 270g of sodium (in reality you are probably dosing twice as much bicarb than calcium chloride) so that is about 900g of salt in total. In a tank your size you would not notice this effect, unless you never did water changes and never checked your salinity.
 
Thanks, Palmer - I actually want to try and maximise the chances of getting rid of the bryopsis in my tank - Anthony Calfo suggested (I read somewhere), that one has to ensure that your pH is around 8.6 and dK at around 12-14....
But, enough hi-jacking this thread - thanks for the answers! :) Appreciate it!
 
Question for all the chemical guru's, i have noticed when adding Calcium Chloride that some of the batches mix up to a brown colour in the RO water. Would this be an inferior grade or bad batch?
 
Is all your calcium chloride from the same batch i.e. bottle?

Then if you are getting colour variations between each batch you prepare the water is the culprit.

Calcium chloride should mix up water white so any brown colour is not good.

Which calcium chloride are you using?
 
No different batches will check the brand tonight. Thanks Clinton.
 
Okay after loosing faith in the calcium chloride i decided to go for broke and double up on the kalk additions and damn what a surprise. I started to dose 2tsps kalk slurry mixed with vinegar to keep ph down at night and 2tsp of the same in the morning. I took a ca reading on Saturday and ca was at 430 and dkh at 9. I have never been able to have both kh and ca that high at the same time. So cheers to the calcium chloride.
 
Could the same thing not be achieved by just dosing kalk. ie use fans to increase/decrease evaporation and or simply by increasing your kalk saturation level. Thinking more about simplicity, continuity, and stability.

Have there been any noticeable changes or observations that you have made whilst using CaCl2, specifically your Acros but not limited to.
 
Mmm I'd like to hear from some of the chemical Guru's as to wether one form or the other would lead to an ionic imbalance.

I'm also dosing kalk via the slurry method at the moment. Two reasons being one to supplement CA which on my system demand is high and the CA reactor can't cope and secondly to maintain my PH above 8.2 on the low.
By reactor is also not coping with ALK either at the moment so I'm needing to supplement that as well.
But back to the Kalk. I'm dosing 1 spoon kalk, mixed with 10ML of Vinegar and cold water in a cup which I stir and add to the system just before lights out.
I've been doing it for about 6 weeks now and can visibly see a difference in the overall health of my tank and inhabitants :)
 
DragonReef said:
Mmm I'd like to hear from some of the chemical Guru's as to wether one form or the other would lead to an ionic imbalance. I am not a guru but kalk would be considered balanced.

I'm also dosing kalk via the slurry method at the moment. Two reasons being one to supplement CA which on my system demand is high and the CA reactor can't cope and secondly to maintain my PH above 8.2 on the low.
By reactor (kalk reactor) is also not coping with ALK either at the moment so I'm needing to supplement that as well.
But back to the Kalk. I'm dosing 1 spoon kalk, mixed with 10ML of Vinegar and cold water in a cup which I stir and add to the system just before lights out.
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I would dump the kalk reactor, and go back to the kalk reservoir. If you still want to supersaturate with vinegar you do it by the drum load. So if you forget or go on holiday, you still keep up the dosing.
Imo the slurry method is a re hash of the original dosing method.
 
Kalk would be considered balanced as it does not add any other ions apart from calcium and it also adds alkalinity as (OH-), but it does not add much buffering capacity which is what we are really measuring when we refer to alkalinity. We are also interested inthsi measure because it tells us how much carbonate and bicarbonate is present which is vital for coral growth.

Species such as hydroxide (and acetate) contribute to the alkalinity readings of our tanks but may in fact give a false sense of security because the alkalinity may be in the correct range, but there could be very little carbonates and bicarbonates present leading to corals not flourishign as they should.

In terms of supplementing alkalinity and calcium, the best method is a calcium reactor.

After that IMO there is really not much to choose between using kalkwasser and a bicarbonate/calcium chloride dosing.

Calcium chloride advantages is that it is very quick, easy and safe to dose. Disadvantage is that ther ewill be soem sort of ionic imbalance over time (but is this really significant anyway? I have not seen any articles investigating this before).

Bicarbonate/carbonate dosing adds these elements directly in a form available for coral growth.

With dosing kalkwasser, it is a bit of a hassle to dose, but the advantage is that what you add will not lead to ionic imbalance. Negatives are as noted above i.e. good alkalinity but not necessarily enough carbonates/bicarbonates (although some hydroxide will convert to bicarbonate with time)

The other small negative if using only kalkwasser IMO is that because kalkwasser is balanced, you may in fact be underdosing "alkalinity" relative to calcium, cause a lot of the alkalinity is used to neutralise acids formed. If using calcium chloride/bicarbonate then it is easy to jsut dose one or the other elements until they are in balance.

Clinton
 
Cool, thanks for the clarification on that Clinton.
 
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