Reef Discussion

[potatocouch]

Apology if I have hammered this forum recently with few threads, which the answer may seem obvious to the expert reefers.

Here's another one, it's about Kalkwasser.

I'm just gonna ramble and chuck in questions here and there. If you see statement that is inaccurate , please do let me know as my understanding can be completely wrong. HAPPY TO BE CORRECTED :)

I've done some quick reading and from my understanding Kalkwasser is a solution that is used to maintain level of Ca & Alk, rather than bringing them up. If so, I'm slightly confused as to maintain but not increase. Ca & Alk drop on daily basis from coral consumption etc. When they say "maintain", wouldn't that mean it brings up the Ca & Alk to the target level?

Kalkwasser should not be used to increase Ca & Alk level; these should be done by dosing 2 parts or in my case, Red Sea Foundation A & B.

As Kalkwasser solution is high in PH, from memory it's Ph 10, it should not be done as a manual top up, rather than to be dosed using peristaltic pump to ensure that the solution gets added to the water gradually drop-by-drop.

When they say as a top up, does this replace the normal RODI water, which I'm doing manually by bucket, to bring the Salinity down due to evaporation?

If so, when adding this solution, meaning we are playing with Ca, Alk & SG. Logically speaking, if I need to add more water to drop the SG, meaning I be increasing Alk & Ca too? Which in some cases, they may already be at the desired level, but not the SG.

Do you use Kalkwasser to maintain your level of Ca & Alk? BTW Kalkwasser is to maintain Ca & Alk right ? How and why people may prefer this, as opposed to dosing by Red Sea Reef Foundation A & B? or Randy's recipe et al? Cheaper? More stable level of Alk & Ca?

 

[192k]

My understanding is that kalk should only be used to maintain calcium and alkalinity because of it's very high pH.

If you were to add a significant amount of kalk to a tank, the pH swing could be disastrous. It has a very high pH (around 12)

For this reason, a two part supplement or calcium reactor should be used to bring the desired levels up.

I would not be adding any kalk or calcium or alkalinity supplements without testing first. Test the usage of your tank and dose accordingly.

SG should not be effected at all because you are just adding the kalk to your RO/DI top-up water. I see your concern about adding too much with a normal top-up though. This could be avoided by the addition of an automatic top up device, electronic or physical float valve so the amount is slowly added to the aquarium to avoid shock.

 

[Franklin Dattein]

Your understading is mostly correct. Let me iron out the details.

Mantaining vs raising
Kalk raises both CA and Alk at the same rates, while two part allows you to raise Ca and Alk separetely.
So, if your Ca and Alk are low AND in balance, you can use Kalk to raise it without a probem. It turns out is is rarely low and in balance, hence why they recomend two part to bring them up to balance, first.

Kalk's pH
Limewater (water saturated with Kalk) has a pH around 12.5, hence it can raise saltwater's pH fast and significantly. Therefore is has to be dosed slowly. How it is done it is up to you...
Most people drip it at night, so the high pH of the solution can counter balance the low pH of the tank. Also, limewater has the ability to absorb a bit of Co2, which contributes to keepin pH stable.

Sailinity drop from limewater dripping is not a concern, In tanks with low Ca/alk consumption, until you need to dose more than the daily evaporation. Once you reach that pont, Kalk is no longer a good method of supplementation.


Adding kalk to the ATO reservoir is a popular technique, but NOT recommended. When you do that, extra evaporation will cause high dosages, which will cause frequent pH spikes.
Also, the Ca precipitate will shorten the pump livespan quite a lot. Same for dosing with a dosing pump, with will ruin the tubbing very fast.


I wouldn't say people prefer kalk over two part. The trend these days is on Two part, whith dosing pumps being so cheap.
People may still prefer Kalk over two part dosing or a calcium reactor, for a number or resons:
- Its Ability to counter balance low pH and Co2 at night.
- Its ability to precipitate a bit of phospates.
- Simplicity in the short temr. There is no calculations to be done and a lot of beginners have a certain degree of success, without having to perform ca and alk tests.
- Low setup cost. All you need is a bottle dripping a night.

Cost is debatable, as for many time is more expensive than gear.

 

[potatocouch]

thanks @192k

Very informative as always, @Franklin Dattein !

 

[192k]

Your understading is mostly correct. Let me iron out the details.

Mantaining vs raising
Kalk raises both CA and Alk at the same rates, while two part allows you to raise Ca and Alk separetely.
So, if your Ca and Alk are low AND in balance, you can use Kalk to raise it without a probem. It turns out is is rarely low and in balance, hence why they recomend two part to bring them up to balance, first.

Kalk's pH
Limewater (water saturated with Kalk) has a pH around 12.5, hence it can raise saltwater's pH fast and significantly. Therefore is has to be dosed slowly. How it is done it is up to you...
Most people drip it at night, so the high pH of the solution can counter balance the low pH of the tank. Also, limewater has the ability to absorb a bit of Co2, which contributes to keepin pH stable.

Sailinity drop from limewater dripping is not a concern, In tanks with low Ca/alk consumption, until you need to dose more than the daily evaporation. Once you reach that pont, Kalk is no longer a good method of supplementation.


Adding kalk to the ATO reservoir is a popular technique, but NOT recommended. When you do that, extra evaporation will cause high dosages, which will cause frequent pH spikes.
Also, the Ca precipitate will shorten the pump livespan quite a lot. Same for dosing with a dosing pump, with will ruin the tubbing very fast.


I wouldn't say people prefer kalk over two part. The trend these days is on Two part, whith dosing pumps being so cheap.
People may still prefer Kalk over two part dosing or a calcium reactor, for a number or resons:
- Its Ability to counter balance low pH and Co2 at night.
- Its ability to precipitate a bit of phospates.
- Simplicity in the short temr. There is no calculations to be done and a lot of beginners have a certain degree of success, without having to perform ca and alk tests.
- Low setup cost. All you need is a bottle dripping a night.

Cost is debatable, as for many time is more expensive than gear.

Franklin Dattein, great info. What is you view/opinion on kalkwasser's ability to bind phosphate?

 

[Franklin Dattein]

Franklin Dattein, great info. What is you view/opinion on kalkwasser's ability to bind phosphate?

IMO, the PO4 lowering effect is negligible, specially when compared to GFO, AO or carbon dosing.
In normal conditions, Kalk alone wouldn't be enough to bring PO4 to ultra low levels, hence the need to apply a second PO4 exporter method.
I would rather stick to the single method that works, reduce the number of variables and complexity.