Calcium reactor and kalkwasser

[authentic]

Just switched to a calcium reactor from 2 part.ph in tank is running low and I'd like to raise it using kalkwasser.I have my two part reservoirs connected to my apex dos.I don't want to put the lalk in my ato resevoir.is there a good starting point for dosing kalkwasser ml/day?
Better day or night?will it effect my alk and calcium?any advice appreciated

 

[Randy Holmes-Farley]

If you add enough, it certainly helps maintain calcium and alkalinity, just like the reactor.

You have any idea what you daily demand for alkalinity is, in dKH per day?

 

[authentic]

95 dkh per day

 

[reef life]

What is your current PH with the reactor?

 

[Randy Holmes-Farley]

95 dkh per day

Huh?

Neither 95 nor 9,5 seem likely, although the latter might be possible.

 

[authentic]

Sorry dkh w reactor is prently 7.8 but I’m still dialing it in tank ph 7.8 as well ( just a coincidence)

 

[Randy Holmes-Farley]

Sorry dkh w reactor is prently 7.8 but I’m still dialing it in tank ph 7.8 as well ( just a coincidence)

What I'm trying to get at is if you dosed nothing, how much would alk decrease in a day.

That's the only way to know that you aren't overdosing the limewater/kalkwasser, even without the reactor. But you can approach it by trial and error if you do not know this.

In a system with enough demand for calcium and alkalinity such that the alk wouldn't rise too much, I'd typically dose to just under the daily evaporation amount using saturated limewater (2 level teaspoons per gallon of RO/DI). and then use the reactor to add whatever else you need to reach your target (if any).

 

[Ammocan]

If I am using a Kalk stirrer and running my ATO water through it do I mix the kalk based on the amount the stirrer holds or the amount my ATO resivoir holds? (10 gal)

 

[Randy Holmes-Farley]

If I am using a Kalk stirrer and running my ATO water through it do I mix the kalk based on the amount the stirrer holds or the amount my ATO resivoir holds? (10 gal)

You put the calcium hydroxide solids into the stirrer in an amount that the stirrer is designed to hold. It can be hard to control potency with a stirrer, but the frequency of stirring is one way.

 

[Dennis Cartier]

What I found with my Avast stirrer was that it was easy to over or under dose depending on consumption compared to evaporation and decreases in strength. To moderate this, I setup my kalk stirrer to get a set amount dosed through it (at night) which is lower than my lowest evaporation, and let my normal ATO pick up the slack. Kind of like how Randy was suggesting splitting the dosing between kalk and a CaRx, except for ATO duty.

To monitor when the kalk is expended and needs a refill, I have a PH probe in the stirrer that allows me to monitor when the PH starts to fall, which signals that the kalk is no longer fully saturated. I also extended the fill line lower in the Avast to get it closer to the undissolved kalk to help make sure that the water that is overflowing from the reactor, is fully saturated.

After these tweaks, my Alk stays at 7.8 - 8.0 pretty much 24 hrs a day and keeps my PH between 8.0 and 8.15.

Dennis

 

[aecombie]

What I found with my Avast stirrer was that it was easy to over or under dose depending on consumption compared to evaporation and decreases in strength. To moderate this, I setup my kalk stirrer to get a set amount dosed through it (at night) which is lower than my lowest evaporation, and let my normal ATO pick up the slack. Kind of like how Randy was suggesting splitting the dosing between kalk and a CaRx, except for ATO duty.

To monitor when the kalk is expended and needs a refill, I have a PH probe in the stirrer that allows me to monitor when the PH starts to fall, which signals that the kalk is no longer fully saturated. I also extended the fill line lower in the Avast to get it closer to the undissolved kalk to help make sure that the water that is overflowing from the reactor, is fully saturated.

After these tweaks, my Alk stays at 7.8 - 8.0 pretty much 24 hrs a day and keeps my PH between 8.0 and 8.15.

Dennis

I know this is an old thread, but what is the ph inside your kalk stirrer, and how low does it drop before you figure it’s depleted and needs to be replenished?

 

[Dennis Cartier]

I know this is an old thread, but what is the ph inside your kalk stirrer, and how low does it drop before you figure it’s depleted and needs to be replenished?

To be honest, I don't remember, but I think it was around 11 - 11.5 PH. I seem to recall that 10 - 10.5 was my signal that the Kalk was weakening. I don't use the kalk stirrer anymore. I used it for a long time, but laziness caused issues eventually. I think at one point, I over filled it to combat the previously mentioned laziness and twisted the mixer bar loose. Back then I was testing alk manually, but today I use an Alkatronic (which I love). If I were going to employee a kalk stirrer today, I would use the several times per day alk measurements from it, to help monitor the kalk strength.

I have a brand new large Avast stirrer sitting here that I had planned to use on my 500G build, but I want to see if I can just get by with the ACR CalRx that I purchased for the same build.

If you are diligent about maintenance, kalk stirrers are hard to beat for cost effectiveness and good results.

Dennis

 

[aecombie]

To be honest, I don't remember, but I think it was around 11 - 11.5 PH. I seem to recall that 10 - 10.5 was my signal that the Kalk was weakening. I don't use the kalk stirrer anymore. I used it for a long time, but laziness caused issues eventually. I think at one point, I over filled it to combat the previously mentioned laziness and twisted the mixer bar loose. Back then I was testing alk manually, but today I use an Alkatronic (which I love). If I were going to employee a kalk stirrer today, I would use the several times per day alk measurements from it, to help monitor the kalk strength.

I have a brand new large Avast stirrer sitting here that I had planned to use on my 500G build, but I want to see if I can just get by with the ACR CalRx that I purchased for the same build.

If you are diligent about maintenance, kalk stirrers are hard to beat for cost effectiveness and good results.

Dennis

I totally feel you on the tank laziness syndrome. You’ve semi convinced me to consider the alkotronic. My goal in this hobby is to simply have a beautiful reef that I can watch with minimal maintenance . I’m currently dosing two part but am going to be switching over to a calcium reactor in the near future. However, right now my ph sits between 7.7 and 8.0. I’m concerned that the ph will drop further once I implement the calcium reactor. I also have an avast k1 kalk stirrer that I got about 5 years ago when I started and didn’t really know what the heck I was doing, so took it off and have had it storage. But due to the low ph, I’m thinking about putting it back on line.
Someone should invent a kalk reactor that automatically discards old kalk and replenishes it with new kalk. That’s really what’s I need
This whole idea of using kalk in conjunction with a calcium reactor might be counterproductive since my intention of getting a calcium reactor is to in fact have less maintenance.
Thanks for your response. It sounds like you’ve got a beautiful tank.
-Joe

 

[Dennis Cartier]

I totally feel you on the tank laziness syndrome. You’ve semi convinced me to consider the alkotronic. My goal in this hobby is to simply have a beautiful reef that I can watch with minimal maintenance . I’m currently dosing two part but am going to be switching over to a calcium reactor in the near future. However, right now my ph sits between 7.7 and 8.0. I’m concerned that the ph will drop further once I implement the calcium reactor. I also have an avast k1 kalk stirrer that I got about 5 years ago when I started and didn’t really know what the heck I was doing, so took it off and have had it storage. But due to the low ph, I’m thinking about putting it back on line.
Someone should invent a kalk reactor that automatically discards old kalk and replenishes it with new kalk. That’s really what’s I need
This whole idea of using kalk in conjunction with a calcium reactor might be counterproductive since my intention of getting a calcium reactor is to in fact have less maintenance.
Thanks for your response. It sounds like you’ve got a beautiful tank.
-Joe

Using Kalk with a CalRx is a pretty common way of combating the tendency of CalRx units to depress the PH slightly. However if your PH is really dropping to 7.7, that is pretty low already. To confirm it, I would consider calibrating your PH probe. Sometimes the easy way of improving PH is to just correct any (possible) measurement errors.

If you have confirmed your PH is accurate at 7.7, you may want to see if you can improve that. Anything below 7.9 would give me cause for concern. The normal cause of depressed PH is CO2 too high within the room/house air. If your location is amenable to it, opening a window near the tank for a few hours and watching the PH can help determine if this is the case. An easier way (though less affordable) of determining high CO2, is to get a CO2 monitor. Desktop units can be had for around $100 that will display the CO2 concentration. I have one in my fish room and can usually tell if I need to perform maintenance on my HRV or furnace filters. I normally run around 460 ppm, though as of right now, it is running 550 ppm as I am using the basement, which also contains the fish room, as my main living quarters while renovations are underway upstairs. A high reading would be 1000+ ppm and would account for a 0.1 - 0.2 lowering of PH.

If you do find opening the window helps, then either running an outside airline to your skimmer or improving the air exchange in the house would be helpful. The outside skimmer line (which I use as well) usually gives you a 0.1 - 0.15 lift in PH where the internal air has a higher CO2 concentration.

Dennis

 

[rmurken]

+1 for calibrating your pH probe. That got me a bump of .2 or .3! (Ooops.)

For easy (albeit without auto replacement of CA(OH)2) automatic KW stirring, I have an old reactor vessel on a magnetic stirrer. Doser pushes RO into the bottom; saturated KW out the top. Stirring comes on for two minutes every hour—enough to circulate but not cause a vortex. I’m going to switch to a lab-type filtration flask, with a one hole stopper to feed RO in, and use the neck barb for the KW outlet. Maintenance would be popping out the stopper and scooping in more CA(OH)2.

 

[Dennis Cartier]

+1 for calibrating your pH probe. That got me a bump of .2 or .3! (Ooops.)

For easy (albeit without auto replacement of CA(OH)2) automatic KW stirring, I have an old reactor vessel on a magnetic stirrer. Doser pushes RO into the bottom; saturated KW out the top. Stirring comes on for two minutes every hour—enough to circulate but not cause a vortex. I’m going to switch to a lab-type filtration flask, with a one hole stopper to feed RO in, and use the neck barb for the KW outlet. Maintenance would be popping out the stopper and scooping in more CA(OH)2.

You will also need to empty and discard the precipitated CaCO3. I had a similar plan awhile back to have a small sealed jar inline my RODI to hold Kalk, thinking that having it sealed to all air, it would not weaken. Then Randy pointed out that the RODI being fed in will still contain CO2, so a slurry of precipitated CaCO3 will still build up. It is the build up of CaCO3 that can make it appear that you still have lots of undissolved kalk available, when in fact you have very little or even none left.

Dennis

 

[rmurken]

Definitely agree. CaCO3 (and random other precipitate sludge) is a fact of using kalk under any realistic circumstance. I’d bet even using ultra pure water without CO2, in a perfectly sealed system, you’d still get some kind of insoluble remnant, since I doubt kalk powder is necessarily all that pure.

If I go insane enough, I have a huge 250ml syringe that I could hook up to the RO input at maintenance time to pull out the CaCO3 sludge, and then replace it with a thick slurry of fresh kalk. Won’t be perfect but doesn’t have to be.

 

[Randy Holmes-Farley]

I know this is an old thread, but what is the ph inside your kalk stirrer, and how low does it drop before you figure it’s depleted and needs to be replenished?

pH is not a good measure. A drop of 0.3 pH units is more than a 50% drop in potency.

Conductivity is a far better way to measure potency. Saturation is about 10.3 mS/cm, and potency is approximately linear with conductivity.

 

[Randy Holmes-Farley]

To be honest, I don't remember, but I think it was around 11 - 11.5 PH. I seem to recall that 10 - 10.5 was my signal that the Kalk was weakening.

Dennis

That's not a good plan. Saturated limewater has a pH around 12.54 (at 25 deg C), and 11.54 is less than 10% saturated. 10.54 is less than 1% saturated.

 

[Dennis Cartier]

pH is not a good measure. A drop of 0.3 pH units is more than a 50% drop in potency.

Conductivity is a far better way to measure potency. Saturation is about 10.3 mS/cm, and potency is approximately linear with conductivity.

Oh, I totoally forgot you had pointed that out in the past. I actually purchased a conductivity meter just for monitoring kalk. I don't remember how well it worked though. I stopped using kalk not long after that.

That's not a good plan. Saturated limewater has a pH around 12.54 (at 25 deg C), and 11.54 is less than 10% saturated. 10.54 is less than 1% saturated.

Yup, ditto with the quote above. Not only did I forget the PH ranges, but I also forgot I had started along the path of using EC.