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Calcium Reactor or 2 Part?

Mike Lemming

Well-Known Member
BRS Member
Hey guys,
I've been toying with the idea of taking my calcium reactor offline and switching to 2 part, mainly for the pH increase. My tank doesn't consume a whole lot, but at 1ml a minute (lowest setting on my Kamoer doser) it is keeping my Alk stable between 8.4 and 8.6. That being said, my tank is in the basement and the pH (for the last week per my Apex) is reading a low of 7.7 and high of 7.95. Even with the basement windows open during the summer, it doesn't go much above 8.
Would you guys just continue with the calcium reactor because it is stable? Or, would you implement 2 part dosing for the pH increase? I already have a dosing system and would just want to purchase new Cal/Alk solution.
I've thought about kalk, but wouldn't want to run it without a kalk reactor and that's just more money to spend..
Thanks for the input!!
 
I would calibrate the pH probe first.
 
If the coral are doing great, I won’t change a thing.
 
If the coral are doing great, I won’t change a thing.
Unfortunately, they're not doing great and I assume it's because of high nutrients. I've been on a mission to lower my No3 and Po4 for about a month now. Po4 is good now around .05 and No3 is getting better but still around 30 give or take. I'm wondering if higher pH would help..
 
Are you feeding frozen food heavily?
 
How big is your total volume? If it's smaller I'd say 2 part as I've had great success and growth with as big as 55-65 gallons but I have never run CA reactors as I have never had a big enough tank or SPS dominant tank to justify the cost...
 
have you ever try kalkwasser? before i ran my calrx i was running co2 scrubber and it did help with the ph but then in the long run its not really ideal when i have to replace the media like every 2-3 weeks. So i just add in kalkwasser and it did help with the ph a lot. And when the kalkwasser coudnt keep up with the alk consuming i add in the calrx and tune in with the kalkwasser dosing so it can keep the ph in range of 8.1-8.3.
 
How big is your total volume? If it's smaller I'd say 2 part as I've had great success and growth with as big as 55-65 gallons but I have never run CA reactors as I have never had a big enough tank or SPS dominant tank to justify the cost...
It's 130 gallons total water volume. Uptake isn't much but I like to keep it stable. I have a pretty decent calcium reactor setup but was interested in the pH boost.
 
have you ever try kalkwasser? before i ran my calrx i was running co2 scrubber and it did help with the ph but then in the long run its not really ideal when i have to replace the media like every 2-3 weeks. So i just add in kalkwasser and it did help with the ph a lot. And when the kalkwasser coudnt keep up with the alk consuming i add in the calrx and tune in with the kalkwasser dosing so it can keep the ph in range of 8.1-8.3.
I've never really been successful with kalk, but I like the idea of it. I was just trying to avoid purchasing a kalk reactor. Maybe I'll have to take a look at these Black Friday deals. Thanks!
 
I got a 30g drum of kalk and just fill it once a month, cheap and easy. Chris meckley would say you dont need a kalk reactor, just a drum and doser.

I planned to run kalk until the tank needed more than i can give and then switch to CARX or 3 part (tropic marin). Still on the fence.

All im doing right now is dosing soda ash solution.

If you want simplicity, maybe go the kalk route if your tank doesnt have a crazy alk demand. How many dKh do you drop in 24hrs?
 
As far as Nitrate at 30 ppm, IMO it is not a problem. I have seen plenty of tanks with over 50 ppm nitrate but thriving.
Higher pH won’t help lower nitrate level.
what kind of issue do you see on coral?
 
I like 2 part better than kalk and I used the alk that raised pH (can't remember which one off the top of my head too exhausted). I also like that if 2 part accidentally overdoses in theory it won't crash the tank as quickly as a kalk overdose.

And kalk is dependent on evaporation where IMO 2 part is easier to add set amount and only need to worry about the slow increase in salinity over time.
 
I like 2 part better than kalk and I used the alk that raised pH (can't remember which one off the top of my head too exhausted). I also like that if 2 part accidentally overdoses in theory it won't crash the tank as quickly as a kalk overdose.

And kalk is dependent on evaporation where IMO 2 part is easier to add set amount and only need to worry about the slow increase in salinity over time.
Note kalk is only dependent on evaporation if you link it to your ATO. It can be dosed separate from your ATO at a set amount per day. The limit is how much your tank evaporates per day. If you evaporate 1gpd and replace 1gpd with kalkwasser your ATO never turns on. Any more than that you’ll overfill the tank, and less and the ATO handles it the remaining water need.

2 part doesnt have that issue since it is more potent you’ll not hit your evaporation limit with it.
 
I got a 30g drum of kalk and just fill it once a month, cheap and easy. Chris meckley would say you dont need a kalk reactor, just a drum and doser.

I planned to run kalk until the tank needed more than i can give and then switch to CARX or 3 part (tropic marin). Still on the fence.

All im doing right now is dosing soda ash solution.

If you want simplicity, maybe go the kalk route if your tank doesnt have a crazy alk demand. How many dKh do you drop in 24hrs?
Honeslty, I don’t even know the consumption because I’ve been running the calcium reactor at such a low dose rate and just maintain its level. I haven’t had it not running for a full day to know. Not much though if I have to guess..
 
As far as Nitrate at 30 ppm, IMO it is not a problem. I have seen plenty of tanks with over 50 ppm nitrate but thriving.
Higher pH won’t help lower nitrate level.
what kind of issue do you see on coral?
yes, I’ve seen tanks with much higher nutrients than mine doing well. The majority of my corals are doing fine (LPS and softies) but I’m struggling with SPS. They have browned out/loss most of their color. No polyp extension (other than a purple stylo). All my sps are relatively “easy to keep” and they’re not doing well, at all. I just can’t figure out what the issue is. I recently changed up the flow from 2 mp40’s to 2 gyre 350’s and also ordered a par meter that should be here Saturday. Maybe it’s too low light? Alk, cal and mag are all fine. I have an icp test somewhere, it’s probably time to send it in. I also ordered everything except a membrane to reset my rodi, will order the membrane here soon.
 
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I like 2 part better than kalk and I used the alk that raised pH (can't remember which one off the top of my head too exhausted). I also like that if 2 part accidentally overdoses in theory it won't crash the tank as quickly as a kalk overdose.

And kalk is dependent on evaporation where IMO 2 part is easier to add set amount and only need to worry about the slow increase in salinity over time.
That’s what I was thinking too. Although the calcium reactor is almost set and forget!
 
yes, I’ve seen tanks with much higher nutrients than mine doing well. The majority of my corals are doing fine (LPS and softies) but I’m struggling with SPS. They have browned out/loss most of their color. No polyp extension (other than a purple stylo). All my sps are relatively “easy to keep” and they’re not doing well, at all. I just can’t figure out what the issue is. I recently changed up the flow from 2 mp40’s to 2 gyre 350’s and also ordered a par meter that should be here Saturday. Maybe it’s too low light? Alk, cal and mag are all fine. I have an icp test somewhere, it’s probably time to send it in. I also ordered everything except a membrane to reset my rodi, will order the membrane here soon.
What kind of lights are you running?
 
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