KH Buffer - tips on dosing?

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Hi Guys, I tested my carbonate hardness and it was 5 dKH. I know that it must be between 7 and 12 for marine tanks. I purchased REEF LIFE KH buffer made by Aqua Medic. All it says on the label is: "... to dose the KH buffer, a stock solution has to be prepared. Dissolve one bag (375g) in 5 litre R/O water. 25ml are enough for an average reef aquarium with a 100 litres volume per day..."
OK, so I have a 300 litre system, which means I must add 75ml per day(3 x 25ml). After 3 days it was still about 5. In your experience, how long before it will pick up and how do you keep it stable?
 
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I dont know this product and what it consists of but can give you a rough guideline.

375g/5l = 0.075g/ml = 1.88 g/25ml.

If this is bicarb then this quantity (25ml/100l) should raise alkalinity by 0.6 dKH

If it is sodium carbonate it should raise alkalinity by around dKH by 1.00 dKH.

If a blend then anywhere in between 0.6 and 1.00 dKH.

So you should see an increase at your dosing levels. Did you measure the alkalinity a coupel of hours after dosing or only 3 days later?.

It is possiblt that your system is consuming the alkalinity at the same rate you are adding it. You may need to increase your dosage levels until you reach where you want to be, and then reduce back to your current daily dose to maintain the levels.
 

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I increased the dose from 75ml to 150ml yesterday and today. I just measured and it was 7dKH. Do I now have to keep this solution in a separate container and dose manually everyday? The problem with this is that my auto top up will never work because I introduce R/O water manually now and there will be no calcium added through my kalkwasser. Also if less than 150ml water evaporates daily then my salanity will drop because I dose 150ml per day. Can I put this solution in my R/O top up compartment? The problem I see with this is I won't know how much KH buffer is introduced daily.
 
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Just add it manually every day, or install a dedicated dripper or dosing pump to add it automatically, but DON'T add it with kalk, calcium or other supplements.

Also be aware that one large dose could cause the water's pH to increase quite dramatically - it would be better to add it slowly in small increments over (say) an hour.

You could save yourself a load of money by using normal bicarbonate of soda (koeksoda) bought from your local chemist or supermarket (I use Buffalo brand, but Robertsons is just as good.)

Hennie
 

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Just add it manually every day, or install a dedicated dripper or dosing pump to add it automatically, but DON'T add it with kalk, calcium or other supplements.

Also be aware that one large dose could cause the water's pH to increase quite dramatically - it would be better to add it slowly in small increments over (say) an hour.

You could save yourself a load of money by using normal bicarbonate of soda (koeksoda) bought from your local chemist or supermarket (I use Buffalo brand, but Robertsons is just as good.)

Hennie
Thanks Hennie, will do so. I shall first use up this KH buffer and then get koeksoda, because it looks like this will be a ongoing process to keep the carbonate hardness levels right. How do you mix the koeksoda(parts koeksoda?parts water?) and how much do you dose at a shot?
 
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Use the post reply I posted as a guide. One gram of baking soda (sodium bicarbonate) per 100l will raise your dKH by 0.33. Max solubilty is around 80g/litre.

If you bake the bicarbonate of soda in an oven at around 160C for 2 hours you will convert it to sodium carbonate which is much more soluble. One gram of baked bicarbonate of soda (sodium carbonate) per 100l will raise your dKH by 0.53
 
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I am using Triple Buffer. Never knew you could use BiCarb.

I use Calcium Hydroxide for calcium supplement, is this OK?
 
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so far so good.raised my alk last week from 5dkh to 8dkh.so it works :)

what test kit are you using?

5 DKH and sps colour like that?
 
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... it looks like this will be a ongoing process to keep the carbonate hardness levels right.
Yup, it's like feeding the fish, you never stop. Just be aware that the calcium and alkalinity must remain balanced. Tanks use up more alkalinity than calcium, but if you only add alk and no calcium, you will eventually have problems. Also, adding only alkalinity will cause an unbalancing of the sodium:chloride ions (the main components of salt-water...), as alkalinity only adds sodium... and then you must also keep the magnesium in balance, and potassium, and... So, welcome to the never-ending balancing act of keeping marines :whistling:

Oh, it's not really that bad if you used a balanced additive (such as dripping kalk, running a calcium reactor or adding a "two-part" additive such as koeksoda and calcium chloride ("turbo calcium...) and the occasional dose of Epsom salts. :)

How do you mix the koeksoda(parts koeksoda?parts water?) and how much do you dose at a shot?
On your 300l system I would start with one teaspoon of koeksoda dissolved into 1 litre of RO water, mix well until dissolved, let it stand for 5 minutes, and then pour the solution into your overflow or into the sump close to the inflow (assuming you have a sump...) in four pours (i.e. 250ml at a time) over a period of 30 minutes to 1 hour. If you do not have a sump then you should pour it directly in front of a power head outlet to ensure good dispersion. In this case, I would add less more frequently, especially if using the baked koeksoda, as it tends to increase the water's pH quite rapidly for a short time.

Hennie
 

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Yup, it's like feeding the fish, you never stop. Just be aware that the calcium and alkalinity must remain balanced. Tanks use up more alkalinity than calcium, but if you only add alk and no calcium, you will eventually have problems. Also, adding only alkalinity will cause an unbalancing of the sodium:chloride ions (the main components of salt-water...), as alkalinity only adds sodium... and then you must also keep the magnesium in balance, and potassium, and... So, welcome to the never-ending balancing act of keeping marines :whistling:

Oh, it's not really that bad if you used a balanced additive (such as dripping kalk, running a calcium reactor or adding a "two-part" additive such as koeksoda and calcium chloride ("turbo calcium...) and the occasional dose of Epsom salts. :)



On your 300l system I would start with one teaspoon of koeksoda dissolved into 1 litre of RO water, mix well until dissolved, let it stand for 5 minutes, and then pour the solution into your overflow or into the sump close to the inflow (assuming you have a sump...) in four pours (i.e. 250ml at a time) over a period of 30 minutes to 1 hour. If you do not have a sump then you should pour it directly in front of a power head outlet to ensure good dispersion. In this case, I would add less more frequently, especially if using the baked koeksoda, as it tends to increase the water's pH quite rapidly for a short time.

Hennie
My main display is only 162 litres, then I've got a sump and 2 refugiums (small Reef octopus refugium and a 85 litre refugium).
I run my R/O water top up through a kalkwasser, so if I add a litre of koeksoda mix then the water level in the sump will rise and my top up float switch will not work for some time, meaning no kalkwasser will be added.
Should I remove a litre of water prior adding that mix? Won't this stuff up my salanity if I do this everyday?
 
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Can you mix the koeksoda in a litre of water from your tank? Then you are essentially not adding or removing any water from your system.
 
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You would be removing calcium. I would like to hear what the gurus say.

But from my elementary understanding, the relationship between calcium and alkalinity exists in a dynamic equilibrium. When one goes up the other goes down. So by adding excess of one you are stripping the water of the other. You would also reach a point that buffer refuses to dissolve depending on how concentrated the solution. ie saturation
 
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...I run my R/O water top up through a kalkwasser, so if I add a litre of koeksoda mix then the water level in the sump will rise and my top up float switch will not work for some time, meaning no kalkwasser will be added.
OK, did not know that you added kalk as well. You should be able to dissolve the koeksoda in much less water (1 teaspoon in a cup should still work...), I only suggested the 1 litre because a greater dilution is normally safer (with adding just about anything, not just alkalinity...).

Should I remove a litre of water prior adding that mix? Won't this stuff up my salanity if I do this everyday?
As long as your evaporation rate is higher than the 1 litre per day, the slight dilution will just reverse again as the water evaporates, leaving you with the same salinity as before, but this will obviously impact on the amount of kalk your auto-topup will supply to the tank - and that's not good. Of course, there are ways to correct this -
  • if you are not currently adding a saturated kalk solution, you could increase the concentration and add less volume for the same effect.
  • you could add a fan to blow over the tank or sump, and remove any cover glasses you might have on the tank (which you should do in any case...). This will increase evaporation, allowing for more additive addition.
  • not sure of what temperature you keep the water, but a slightly higher temp (not more than 28.5 ºC on average) will increase evaporation as well.
Hennie
 

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  • you could add a fan to blow over the tank or sump, and remove any cover glasses you might have on the tank (which you should do in any case...). This will increase evaporation, allowing for more additive addition.
  • not sure of what temperature you keep the water, but a slightly higher temp (not more than 28.5 ºC on average) will increase evaporation as well.
I've got a small extractor fan over my sump - more for getting rid of the humidity inside I suppose. Got no covers on my tank or sump and I keep my temp 26deg with a chiller.
 

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