Kalkwasser issues

[Randy Holmes-Farley Verified Community Expert]

What are possible reasons?

Two likely reasons.

As the aquarium pH rises from less CO2, the demand for calcium and alkalinity by corals and the abiotic precipitation of calcium carbonate both rise.

So alkalinity declines if the alk delivered is unchanged.

Changing seasons may also impact the evaporation rate which will alter the amount delivered.

 

[SteadyC]

1.Thanks for that.
2. At the time of mixing I have 5 gallons of saturate solution remaining, I dump the 30 teaspoons on top of that then pump in 15 gallons. You are saying the bottom 5 gallons is wasted?

No not really. What I’m trying to say, is the bottom part of the kalk is super saturated, and the top part is the clear stuff you want to add to your tank, not the bottom stuff. That’s why you always seen the tube or hose never goes to the bottom of the kalk tank. It’s super saturated down there. Then, you are mixing in a saturated level of kalk at 2 tsp kalk to 1 gallon water, and thus the kalk you are now pouring in, isn’t fully utilized as the water can’t saturate anymore kalk, as it’s already super saturated. There are ways to increase the saturation level of kalk to water, such as by adding vinegar, but you didn’t mention that you are doing this. So, I am basically saying, you are adding kalk that can’t/won’t mix with the water and thus wasting what powder you are adding each time, and continually adding to the slurry at the bottom.

 

[SteadyC]

Yes, but it ALWAYS does. There is never any important amount of free hydroxide in the water.

The added hydroxide immediately combines with H2CO3 to form bicarbonate and with bicarbonate to form carbonate to form (and boric acid to form borate).

Unless the pH is too high, there is no concern about free hydroxide. Even at pH 9, the free hydroxide is only 0.01 meq/L or 0.03 dKH.

Interesting, I always thought the co2 was a required component too. We are at the point now, that chemistry hurts my little brain, .

 

[Randy Holmes-Farley Verified Community Expert]

Interesting, I always thought the co2 was a required component too. We are at the point now, that chemistry hurts my little brain, .

We try to ease that pain, [emoji23]

 

[Jizu Puentes]

Been running kalkwasser using the resevoir method on my show tank for close to 15 years. The 1 concern with your process that I have is mixing every 30days. Target a 10-14 day supply. The potency may be going down the further out beyond 14 days that you go. Best would be to test it with a conductivity meter to see what the potency loss is at 30days if you really wanted to know.

Don't forget when using the resevoir method that can boost by adding some vinegar to get up to 30% more alk delivered. But again, best not to go beyond the 10-14 day interval.

When I need to make alk adjustments, I will do a kalk slurry ( assuming it won't spike pH too much ). I usually avoid carbonate/bicarbonate additives for alk adjustments becuase that throws off my ca levels and I really try to avoid adding chlorides when ever possible becuase I do near zero water changes.

For me, my tank is most vulnerable in the summer time. Close up the house for A/C. Evap goes down, more co2 because windows are shut, pH starts to fall. When pH falls alk consumption drops so I have to be very careful that alk levels dont get too high. In winter when the air is dryer due to running furnace, my tank evap goes up, co2 levels aren't as high becuase all the fresh air the furnace pulls in compared to A/C running, pH goes up, alk usage goes up and is a non issue.

I didnt think the potency changes if the container is sealed and the solution is still, not stirred or anything.
I raised the Alk level with just the oceans blend part 2 because my CA level was reading 420 and I'm fine with the CA staying there, only wanted to raise the kh.

 

[Jizu Puentes]

Yes, but it ALWAYS does. There is never any important amount of free hydroxide in the water.

The added hydroxide immediately combines with H2CO3 to form bicarbonate and with bicarbonate to form carbonate to form (and boric acid to form borate).

Unless the pH is too high, there is no concern about free hydroxide. Even at pH 9, the free hydroxide is only 0.01 meq/L or 0.03 dKH.

I'd like to say that I understand this....but nope haha.

For my situation it definitely sounds like opening the windows caused this effect because I did see both CA and KH decrease and PH increase.

I remember reading that you use a still reservoir as well, a brute can if I remember correctly. How long does your solution last you? Is my 30 day supply an issue and is mixing my new solution with the slurry on the bottom an issue if I let it all settle before dosing?

 

[Jizu Puentes]

Two likely reasons.

As the aquarium pH rises from less CO2, the demand for calcium and alkalinity by corals and the abiotic precipitation of calcium carbonate both rise.

So alkalinity declines if the alk delivered is unchanged.

Changing seasons may also impact the evaporation rate which will alter the amount delivered.

My evaporation rate does change but I have my kalk doser and ATO seperate.

 

[Randy Holmes-Farley Verified Community Expert]

I'd like to say that I understand this....but nope haha.

For my situation it definitely sounds like opening the windows caused this effect because I did see both CA and KH decrease and PH increase.

I remember reading that you use a still reservoir as well, a brute can if I remember correctly. How long does your solution last you? Is my 30 day supply an issue and is mixing my new solution with the slurry on the bottom an issue if I let it all settle before dosing?

Mixing and using a settled reservoir in a Brute can unstirred and closed for 30 days is just fine. Solids on the bottom is fine, either excess undissolved calcium hydroxide, or precipitated calcium carbonate and other insolubles.

 

[Randy Holmes-Farley Verified Community Expert]

I didnt think the potency changes if the container is sealed and the solution is still, not stirred or anything.
.

That's correct. I've measured it in such a setting:

The Degradation of Limewater in Air - Reefkeeping.com
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm

 

[Jizu Puentes]

That's correct. I've measured it in such a setting:

The Degradation of Limewater in Air - Reefkeeping.com
http://reefkeeping.com/issues/2003-05/rhf/feature/index.htm

Great read, thanks for that link!

 

[Jizu Puentes]

On November 2nd I raised my kh level to 8.4 and now today, 4 days later it reads 8.0. Should I just up the daily dosage or do I need to dose back to 8.4 then up the dosage?

 

[Randy Holmes-Farley Verified Community Expert]

You need to dose more somehow. Do you know if the limewater you dose is saturated? can you increase the daily amount?

 

[Jizu Puentes]

You need to dose more somehow. Do you know if the limewater you dose is saturated? can you increase the daily amount?

It SHOULD be saturated. I mix the max of two teaspoons per gallon. I can increase the dosage per hour on my pump. It's currently at 63 ml per hour so I can bump it up and see if it stops the reading from going down further

 

[Randy Holmes-Farley Verified Community Expert]

It SHOULD be saturated. I mix the max of two teaspoons per gallon. I can increase the dosage per hour on my pump. It's currently at 63 ml per hour so I can bump it up and see if it stops the reading from going down further

Sounds good.

 

[Jizu Puentes]

Increase evaporation, I run my kalk threw ato , and track threw my apex using atk and flow meter, I have opposite problem than you , I get two much and have to play with my fans and chillers to get more or less evaporation , using bucket system is easy to calculate , double your evaporation sounds like a good start, my goal is to have my kalk reactor do the majority of the work and calcium reactor pick up the slack, when my system is more mature and full, these swings will be of less concerns as the kalk reactor will be maxed , and running off the calcium reactor. Adding vinegar is a good option as well , someone else said that before, that might be enough buy itself, and then play with evaporation, or both, but your close to being on it.

My dosage isn't based on the evaporation because I have my kalk seperate from my ATO and is dosed through a dosing pump. I didnt like running my kalk via my ATO because of the variances in the evaporation and because my skimmer fluctuations make my ATO turn on and off depending on how much it's skimming.

 

[Jizu Puentes]

So your saying if it evaporated more you could not add more kalk, even though it's not on ato,

No I was saying that me increasing the evaporation wouldn't affect my kalk dosage because my dosage isn't based on the evaporation amount. I just increase the amount of kalk dosed on the dosing pump and let the ATO just do its own thing

 

[jimmyzhou]

Before I do the dos on kalkwasser my ph was kind low start at 7.6-7.8. After dos. My ph staty at 8.1-8.3. I’m use those kalkwasser reactor. Ever day. Will be auto move the base kalkwasser blender. For 1 min But still drop ph at night when light is off. Soo I did set up the refugium. Now. Is very nice 8.1-8.3. Dosing kalkwasser will increase cal and magnesium I think just be carful dosing it.

 

[Randy Holmes-Farley Verified Community Expert]

Dosing kalkwasser will increase cal and magnesium I think just be carful dosing it.

Not magnesium. It adds effectively none.

 

[Jizu Puentes]

Before I do the dos on kalkwasser my ph was kind low start at 7.6-7.8. After dos. My ph staty at 8.1-8.3. I’m use those kalkwasser reactor. Ever day. Will be auto move the base kalkwasser blender. For 1 min But still drop ph at night when light is off. Soo I did set up the refugium. Now. Is very nice 8.1-8.3. Dosing kalkwasser will increase cal and magnesium I think just be carful dosing it.

I've been dosing it for overy a year now, this isn't a new addition just questions on maintaining the use of it.

 

[Jizu Puentes]

I don't understand the problem if it's low and on a doser, turn it up some?

The original question was why I experienced a drop in KH and CA if I'm dosing a set amount and what I needed to do to correct it.