Calcium Reactor Issues

I posted this in Lighting & Equpiment but didn't get much back...

I feel like I'm having some kind of issue with my Calcium reactor setup. I've got a Masterflex with an MTC Minical and a Carbondoser. I've got the Apex keeping the pH at around 6.5. I've got a heavily stocked SPS tank that is healthy and growing but Alk is stuck at 5.5-5.8. I can't get it to go up. I've got the flow rate on the Masterflex set to 200 but it seems like no matter what I set it to, the Alk won't rise.

The other thing is, I don't see the actual media burning up at a fast rate? I'm reading accounts of people adding in more media every couple of weeks but I'm not doing that, even though I have the pH set to 6.5.

1) How am I testing? Salifert and Trident. Both report low alk readings. Salifert is reading at about 5.6. For the Trident, its so low I'm getting a "Bad Alk Range" error which means it thinks it is under 5.0.

2) Media Used: Two Little Fishies Reborn

3) Yes I've calibrated the cX reactor probe multiple times with 4.0 and 7.0

4) Calcium is coming up at 463 and magnesium at 1361. This is per Trident. Salifert numbers aren't far off for these two.

5) Salt Used: 1.025 - 1.026, using Instant Ocean

6) Someone suggested I measure the dkH of the effluent. I tested it twice and it came up at 7.15


What should I be looking at? Is it simply time to supplement with 2 part or kalk?
 

vuqchu

Active member
I would test Alk and check pH again with a different test and see. If alk is still low and pH is actually under 7.4 with another probe or recalibrate then I would disregard pH reading and just add more co2 slowly to take alK up. FWIW, my pH probe on the calcium reactor serves as more of a plug to keep it from leaking than actual reading I’m concerned with because it’s been reading around 5 for ages. Too cheap to buy another probe when I know I wouldn’t be checking it anyway. Lol
 

solitude127

Proud user of IO Salt!
Silly question, is the circulation pump on for the CaRx? Do you actually see CO2 being injected into the reactor?
 

wishntoboutside

professional snow flake
A calcuim reactor should maintain the alk at the same level if it is set up correctly. if it is doing that it is great then you can buff with a two part slowly to get it to your desired levels. if it is still dropping you need to increase the flow going out of it. Is your reactor a single chamber or dual chamber reactor. If it is a dual your PH should come out some what higher as well.
 
Silly question, is the circulation pump on for the CaRx? Do you actually see CO2 being injected into the reactor?

Yes the CaRx has an Ehiem 1262 circulation pump. Now, the flow through it seems weak but I was told that was okay. Here is a video of the flow rate through the circulation pump: https://youtu.be/WX4EoJcXLZg

I do see CO2 bubbles in the bubble counter.



Is your reactor a single chamber or dual chamber reactor. If it is a dual your PH should come out some what higher as well.

It is a dual chamber reactor. The second chamber is way smaller than the first.
 

solitude127

Proud user of IO Salt!
Yes the CaRx has an Ehiem 1262 circulation pump. Now, the flow through it seems weak but I was told that was okay. Here is a video of the flow rate through the circulation pump: https://youtu.be/WX4EoJcXLZg

I do see CO2 bubbles in the bubble counter.





It is a dual chamber reactor. The second chamber is way smaller than the first.

a 1262 should be flowing a whole lot more than that.
 
a 1262 should be flowing a whole lot more than that.

I thought the same thing but when I posted that video in the MasterFlex thread in Lighting & Equipment, one of the frequent posters replied:

"Not to worry on the flow, that's the recirculating pump, it runs @ a fixed speed.
"
 

solitude127

Proud user of IO Salt!
I thought the same thing but when I posted that video in the MasterFlex thread in Lighting & Equipment, one of the frequent posters replied:

"Not to worry on the flow, that's the recirculating pump, it runs @ a fixed speed.
"

I'm just thinking out loud here and I'm not 100% sure on this but if there's not enough water circulating in the reactor, then it's not really mixing the CO2 and the water. Yes, I know your PH probe says 6.5 but the alk in your effluent doesn't reflect that and the fact that your not seeing media melt.

How many bubbles per second do you have your carbon doser at?
 

solitude127

Proud user of IO Salt!
I have the Carbon Doser set to 2 or 3 bubbles per second.

Yes the Masterflex is set to 200 mls/minute

with 2 - 3 bubbles per second and your masterflex set to 200 mls per minute, I would highly suspect your PH probe is not correct.
For reference, my old carx, i was at 45mls per minute and I was about 2 bubble per second and my ph reactor was at 6.6. For your setup and with 200mls per minute, the ph in the reactor would be pretty high.
 

kidA

New member
Good thought on recirculating pump being the culprit - I did have that issue for similar reason being unable to raise alk (pump was getting air locked, and not recirculating)

Do me a favor and change your output on the peristaltic pump to about 20 ml/min. Curious what alk will read in 1 day.

Regarding media not depleting. I have a heavily SPS stocked 270 gal tank. And mine also doesn't go down for quite some time. Using the GEO 618. It's pretty amazing how long it lasts. Love the caRX. Will never go back to two part. Media level typically won't go down until it's close to used up then it will drop quite a lot over a short time frame. I have to replace media about twice a year. CO2 about twice a year too to be safe (10 lb).


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Duality

New member
I don't know if this helps but I had an apex 2016 that had bad pH probe sockets. I was having an issue with pH in cal reactor going up during the day to above tank pH. No matter how much co2 I injected into the reactor. I found out it was a apex brain that was bad
 

pa1ntbru5h

New member
I would lower your masterflex rate and watch your CaRX pH to see if it drops.

It's possible your supply is too high and not allowing the media to melt before it comes out the effluent side.

I wouldn't worry about recalibrating the probe again. Just use the current number as a reference point. If you start to see the pH drop 0.1 to 0.2 with the lower flow rate then you know your probe isn't bad.

Alternatively, instead of lowering the flow rate, increase the CO2.
 
About a day after lowering the flow rate through the Masterflex from 200 mls/min to 30, I'm getting an alk reading of ~15 dKH.

So basically did I just have the flow rate set way too high? I originally had the Masterflex set up at 30 mls/min and then at a certain point SPS growth took off and my alk started dropping. I figured I would increase the flow rate but I guess I went too far?
 

kidA

New member
Calcium Reactor Issues

Yes. Flow rate too high/pulling through too fast. Operating with lower flow is also better as it will impact your tank pH less (as you would need to increase CO2 more which would then drive your DT pH down further as well).

Edit: simply put: maintain the low flow as a constant as you were, and only adjust CO2 as needed.

Glad it worked! Happy reefing!


Sent from my iPhone using Tapatalk
 
Yes. Flow rate too high/pulling through too fast. Operating with lower flow is also better as it will impact your tank pH less (as you would need to increase CO2 more which would then drive your DT pH down further as well).

Edit: simply put: maintain the low flow as a constant as you were, and only adjust CO2 as needed.

Glad it worked! Happy reefing!


Sent from my iPhone using Tapatalk

I've lowered the flow rate to 50 mls/min which resulted in an effluent dKH of 11.5. I'm going to see if display alk starts rising. I've already got the ph set to 6.5 -- I'm wondering how much lower I'm able to go? I mean, do people have their reactors set to 6.2, 6.3? That seems too low?

BTW the corals I got from you a while back are all doing great!
 
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