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Calcium reactors vs Kalk Reactors ?

dnov99

FRAG SWAP VENDOR
Biggest con of them both is with a kalk reactor. It can get stuck via either the ATO or the mixer and flood your entire tank with kalk and kill everything.

This happened to me 3 times and luckily I was home all 3 times to shut it down before any major damage occurred. After the 3rd time I got rid of it all together.

With a calcium reactor you also have the benefit of adding MG and other trace elements to your system. CA Rex all the way..
 

The_Codfather

Officer Emeritus
Officer Emeritus
What i was thinking is run a CA reactor and have the kalk dosed with a doser like a litermeter
 
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dnov99

FRAG SWAP VENDOR
What I have been reading is the CA will drop the PH so some people run both

When I ran my Kalk reactor it was solely to lift the PH due the Ca rex lowering it. If you tune in the Ca rex correctly you wont have a problem with lower PH from excess CO2. Honestly I have found that PH means very little as long as you keep it anywhere from 7.8 to 8.3. I have not tested or monitored my PH in 5 years. I find that people do more damage trying keep get their PH at 8.3
 

The_Codfather

Officer Emeritus
Officer Emeritus
Right now I just have a prob keeping my ALK up but that's in my 40gl.. This will be for my upgrade and we all know every system is different
 
I recall phyl recommending a kalk reactor over a calc reactor. Also that the benefits of running both at the same time are even better.

I've run a kalk reactor hooked with my tunze osmolator for almost 2 years now with no issues. My ph has been steady at 8.5/8.6.

i am going to try this product in my reactor next: Brightwell Aquatics Kalk+2

Saw some good reports about it. It will eliminate my need for separately dosing Mag.

Finally with calc reactors you have to deal with the Ozone and tuning that - and I am not an expert to comment on the level of difficulty around that. Just purely based on this, I feel like the kalk reactor yields a positive benefit and is easier to set up.
 
Biggest con with kalk reactor is that it can stick on and kill your whole system. just put the kalk in your ato, way safer way of dosing it.

When my tank was loaded with frags, I was going to get a calcium reactor cause i figured when they grew bigger I would need one. Then i never seen signs of non growth, or anything wrong so i just never got 1. My tank is loaded with large colonies , mostly sps and all is good. Ive only had this tank set up for 20-24 months with coral, got everything as a frag, and i have 5 colonies as big as soccer balls, and many the size of baseballs. All together my pokerstar is the size of a dinner plate, and my 2 undata's are 6 n 8" round, when i got these they were the size of a dime! 1 huge clam, 1 med, 6" leather, polyps, acans, huge purple, orange, n green montis, and many other things. I dont know maybe if i did have a calcium reactor my stuff would b growing even better? I just dont see a need for 1. I just think if u do large frequent wc's with a decent salt, your levels will b close enough. My tank never seemed in need of 1, corals never showed signs they were doing bad , so i just never bothered with 1. I also like that i never had to dish out the cash for 1. Maybe just wait it out n see if u need it?
 
I'm into my Ca Rx, it really has helped my system.

I used to run both the CaRx & kalk Rx fed by my ATO. Due to temp swings in my office setting I was have high Alk issues and pulled the kalk of line. I now dose BW Elemental to the system weekly and fix my new SW with BW Kalk+2 still run the CaRx with BW NeoMag in the second chamber. This is the easiet Ca/Alk maintenance set up I've run to date.
 
I used to run both too. It's a powerful combination, and can really do wonders for your water chemistry.

Unfortunately, I had a number of incidents in which either (A) the Ca Reactor clogged and filled up with CO2, causing the pump to run dry, or (B) (Much Worse) The top up decided to give the reef a large dose just after th kalk reactor had stirred. This causes a large alk swing, which corals hate, and if the chemistry is right can cause a massive depositing of SOLID calcium carbonate on all pipes, pumps, fixtures, etc. I switched to 2-part solution, even though it costs me a few hundred bucks a year, and I enjoy the hobby much more, vacations are more pleasant, etc, etc.
 
When running my kalk mixer, I isolated the mixer to limit the max dose in any one day.

To do that, I used three seperate top off float switches, two RO reserviours, and three timers.

My main RODI make up tank ( a RM BRUTE) is fed from the RODI filters with a seperate Spectrapure top off controller to keep the main vessle full. In the main vessle, a PH with a second float switch set on a timer fills a 10 g ATO reserviour once a day (at night) for 15 minutes. In this way they ATO can only feed 10 GPD thru the kalk mixer to the system. That's an absolute maximum.

To keep pure fresh mixed klak from being dosed, the kalk mixer pump is on a timmer as is the Aquamedic Peristaltic pump that draws from the ATO resiviour based upon the demand of the third float switch in the sump. These two timers are coordinated so the ATO is OFF when the kalk is stirring and does not come back on for about 1/2 an hour after a stirring event so the kalk may settle.

It takes some tinkering to get the timing right. But, this worked great in a temprature stable house/office, but in this rat hole of a shop I'm in now my temps would swing so much that evap was running crazy and I was toppomg off 7 GPD plus on average. As a result I took on too much Alk over time and my ALK would rise. Either it was soooo hot I was getting high evap rates or so cold my heaters were cranking and creating high evap rates. If you have relatively stable ambient temps, this set up will work great in combination with a good CaRX.
 
I have both and been running both with no problems for 3 years. Started with the CA reactor by itself but my PH kept going below 7.7 during the night .
I got the kalk reactor and the PH problem is resolved. To Avoid having a Kalk Dump problem I gravity feed the kalk reactor with my top off water. the container is 2 gallons and is refilled only one a day by the Apex controller. this way if the float valve ever gets stuck the amount of kalk that goes into the system will be limited.
 
The important thing is limiting the MAX amount of klak that can enter your system in any one day.

Regulating volume or time it can be dosed will work.

For example a timer cam be set so a second pump doses via the kalk reactor only at night when pH is low. A "main" ATO pump would address evap with straight RODI water during the day.
 
The Kalk reactor I have is set up in line with the tunze ato. The outflow is gravity fed into the sump.

There is no way for the tunze to ever 'stick' given its set up. At most it runs for 3 minutes straight and then forces a stop completely because it knows the sensor is off. The only risk I run with this setup is that the contents of the Kalk reactor back flow into my ATO container. So I'd have a gallon of kalk dumped into my FO container. Not a big deal and it has never happened yet (knock on wood).

The caveat to this is depending on the weather (high humidity/heat, low humidity/cold) will impact the amount of evap which results in varying levels of kalk dosed. Once the system has matured a little you can adjust the amount of kalk dosed depending on the season. As Bax mentioned above- this could be addressed by setting up a secondary pump/timer to pump kalk only and the ATO to run RODI only. But I prefer no to run another pump so I just hook the ATO directly into the kalk reactor.

The kalk reactor helps make it a set it and forget it proposition - and works well when you are away on vacation/work.
 
danny used to post here a bit too. He had a great set up at one time. I've never been to his place - did he break down everything sid? Anyways I guess the good news here is that he probably kept his equipment in very good condition if my recollection of his tank serves me right.

Just keep an eye on Alk - as the CA reactor will drive that parameter down.
 

dnov99

FRAG SWAP VENDOR
Finally with calc reactors you have to deal with the Ozone and tuning that - and I am not an expert to comment on the level of difficulty around that. Just purely based on this, I feel like the kalk reactor yields a positive benefit and is easier to set up.
Phil Its not Ozone that runs on a calcium reactor, its CO2.
Just keep an eye on Alk - as the CA reactor will drive that parameter down.


A calcium reactor will not drive down ALK. That is a myth. If anything these reactors should be called Alkalinity reactors because that is what they supply. I dont even bother testing for calcium, I have not in 5 years. Keep your alkalinity at a stable, balanced level and calcium and PH will all fall in line. The key is just getting the reactor tuned in properly. The need to run a Kalk reactor in addition is a complete waste. The media from a Calcium reactor will provide so much more than just calcium and alkalinity. It provides trace elements MG, etc.

Most people who have problems with Calcium reactors is a result of them not getting them tuned in properly to begin with or using some sort of PH controller, which is the second biggest mistake to do. They also worry about getting their PH raised and usually do more damage trying to keep it high by dosing extra stuff. I have not checked my PH in years, IMO another thing that is fine if its low as long as it is stable. A dip to 7.7 in the evening is fine.
 
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