Home Forums Reef Discussion Calcium Reactor Primer: Theory and Fine Tuning

82 replies, 28 voices Last updated by  Anonymous 7 years, 1 month ago
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  • #331010

    Crewdawg1981
    Spectator

    Okay, so I think I followed your primer to setup my MRC CR2, but I’m definitely having issues getting it dialed in. The biggest problem I’m having is keeping the pH down inside the reactor.

    I’ve got roughly 315 total water volume… though its likely more like 250 gallons of actual water. Mostly SPS frags at this point. A fair amount of frags at that. I’ve been doing a 20 gallon water change with Salinity every 1-1.5 weeks.

    I bought fine media… before finding out I probably should have gone with large… oh well. I filled up my first chamber and half of the second chamber, hooked everything up and let it run without CO2 for a few days. Turned on the CO2 at 60 BPM and then adjusted my effluent to ~50mls per minute and let it sit for a day. At 60 BPM, the pH within the reactor never went below ~7.2. So I adjusted the effluent to ~30 mls per minute at 60 BPM. This had the effect of lowering the pH to ~6.9-7.0. Let that stand for a few days as well and it never really got any lower. Finally, the most recent adjustment was to change the bubble rate. Currently I’m at ~90+ BPM and 50 mls per minute and the pH is 6.77.

    Am I doing this right? The solenoid never has to turn off because I had it set to 6.6.

    Here are the results of my testing:

    Last Monday

    ALK – 2.5 Meq

    CA – 350ish? (Seachem test… can hardly notice the color change)

    pH system – 8.10-8.20

    pH CaR – 7.20-7.40

    Last Weds

    ALK – 2.5-3 Meq

    CA – ~350ish

    pH system – 8.10-8.20

    pH CaR – 6.90-7.10

    Last Night

    ALK – 3.5 Meq

    CA – ~375-400

    pH system – 8.10-8.20

    pH CaR – 6.75-6.80

    #366851

    cbj25
    Spectator

    126 reef;725682 wrote: I have a life reef calcium reactor have been avoiding setting up due to not fully understanding how to dial it in properly. I have decided to get a ph controller, and i wanted one for the reactor itself as well as the main tank to shut off the reactor if the display tank ph drops to low. Any suggestions for a reefer on a budget?

    get a controller to shutoff your calcium reactor if your ca or ph gets to a certain point and then to kick back on when it reaches another

    #331013

    Anonymous
      • Posts:0
      @

    What is the best calcium reactor to geT?

    #337414

    jmaneyapanda
    Participant

    jhutto;658559 wrote: I always thought you got some mg from the coral skeletons. Is that not true?

    A nominal amount. Magnesium supplementation is still necessary.

    #331017

    Hnguyen
    Spectator

    ticks;643912 wrote: What is the best calcium reactor to geT?

    I think that has more to do with user preference. I think geo is the best and their customer service is best I’ve ever seen. I hear MRC also makes great reactors

    #333067

    Anonymous
      • Posts:6522
      @

    I should probably come by…no rush. But post a vid if you like.

    #331020

    Anonymous
      • Posts:467
      @

    Maybe you need to lower effluent rate. And make sure hot not collecting co2 at the top.

    Sent from my PC36100 using Tapatalk

    #332812

    Anonymous
      • Posts:6522
      @

    Your setpoint is midway between the high and low. The hysteresis goes the same increment above and below the setpoint. So if your high point is 6.8 (CO2 turns on) and your low point is 6.6 (CO2 tuns off), then the controller setpoint is 6.7 with a hysteresis of .1 (above and below the setpoint).

    #356621

    michael grady
    Spectator

    Thanks for the advice Dave…looks like between 500 – 600 bucks for a reactor, once you add in the co2 tank etc. I guess there is no sense to just add one until my tank cycles and i begin to add stuff that takes up calcium.

    #331022

    Crewdawg1981
    Spectator

    blakejohn;643927 wrote: Maybe you need to lower the bpm and also lower the rate of effluent. You are looking for drips per min not mls per min.

    ?… the primer says Mls per minute?

    #332814

    Crewdawg1981
    Spectator

    Acroholic;647938 wrote: Your setpoint is midway between the high and low. The hysteresis goes the same increment above and below the setpoint. So if your high point is 6.8 (CO2 turns on) and your low point is 6.6 (CO2 tuns off), then the controller setpoint is 6.7 with a hysteresis of .1 (above and below the setpoint).

    Hmmm… all the Apex asks for is the high, the low and then whether I want the outlet on when the value is at the high or the low… I have it set to be on when the value is high.

    #409870

    bruce 1
    Spectator

    Dave, I might have missed this in the post. I am reading up on calcium reactors and plan to set mine up soon. So what controller do you use? I use RKE but with them you can only use one PH probe. Is that all that is needed? Or do you have one in the reactor and one in the sump? Also the meida for the second chamber do you use the same media as in the first chamber?

    Thanks Bruce

    #331025

    Hnguyen
    Spectator

    Crewdawg1981;643929 wrote: ?… the primer says Mls per minute?

    +1. Even the geo manual states ml not drips.

    But then again, different reactors require different drip rates. My first reactor which was a Corlife says drips per min. So it all depends. That’s when you have to refer to your manual.

    #332821

    Anonymous
      • Posts:6522
      @

    Crewdawg1981;647940 wrote: Hmmm… all the Apex asks for is the high, the low and then whether I want the outlet on when the value is at the high or the low… I have it set to be on when the value is high.

    I see…your Apex has you program the high and low point, and the controller setpoint is midway between those values. The hysteresis is the equal amount above or below the midway point (controller setpoint).

    My RKE has me program the controller setpoint (midway point) and the hysteresis, then the RKE turns the CO2 on/off at the high or low point.

    2 different ways of doing the same thing.

    #337432

    Anonymous
      • Posts:6522
      @

    jmaneyapanda;658556 wrote: Dave- one point in this write up- you mention a few times that a calcium reactor will add water rich in calcium, alkalinity, and magnesium. I don’t think this is accurate. Most media is simply coral skeleton, which is calcium carbonate. Magnesium will not be supplemented by using a calcium reactor as such. People have attempted to use additional media (rich in magnesium), in addition to calcium carbonate in their reactors to supplement magnesium, but I can’t comment on their success. Overall, though, magnesium supplementation cannot be supported by standard calcium reactors, as far as I know.

    Actually, I mention this only once in the write up. My use of the term “rich in magnesium” is probably not accurate in the relative amount of magnesium compared to the amount of calcium and bicarbonate released, but in the write up I state that magnesium is not used extensively in the calcium carbonate skeletons of corals, but that its main function is to limit the abiotic precipitation of calcium carbonate in solution. But it is used in coral skeletons to an extent. To quote Randy Holmes Farley:

    “Whenever calcium carbonate begins to precipitate, magnesium binds to the growing surface of the calcium carbonate crystals. The magnesium effectively clogs the crystals’ surface so that they no longer look like calcium carbonate, making them unable to attract more calcium and carbonate, so the precipitation stops. Without the magnesium, the abiotic (nonbiological) precipitation of calcium carbonate would likely increase enough to prohibit the maintenance of calcium and alkalinity at natural levels”

    jmaneyapanda wrote: Most media is simply coral skeleton, which is calcium carbonate. Magnesium will not be supplemented by using a calcium reactor as such.

    From the Same Randy Holmes Farley article (bold added):

    “An aquarium’s corals and coralline algae can deplete magnesium by incorporating it into their growing calcium carbonate skeletons.

    Randy’s Reef Alchemy article would contradict your point, so dissolving calcium reactor media (coral skeletons) should release the magnesium corals take from the water and incorporate into their skeletons, unless it goes somewhere I am not familiar with besides back into the tank water with the effluent.

    CaribSea, manufacturers of the ARM line of calcium reactor media, also print magnesium levels in this media. For example, ARM Extra coarse has 2000 ppm magnesium. ARM extra fine has 1050 ppm magnesium. So I do not believe it is accurate to state that you cannot supplement magnesium through a calcium reactor.

    But the above being said, most reefers using calcium reactors are probably supplementing calcium, magnesium and bicarbonates from several additional sources, among them water changes with fresh salt mix, their live rock, and any substrate they use.

    My personal experience is that I have not had to add any additional magnesium to my 100 gallon mixed reef, only using a GEO 612 with ARM large media in it. But I also do water changes.

    I certainly would not discount any particular situation that would require additional magnesium supplementation in a reef. But magnesium is incorporated into coral skeletons, and when these coral skeletons are dissolved in a calcium reactor as media, the magnesium should be released in the ratio to calcium and bicarbonates it was originally taken up at by the corals.

    Referenced Reef Alchemy Series article by Randy Holmes Farley:

    http://reefkeeping.com/issues/2004-05/rhf/index.php

    #346649

    Kenlude
    Participant

    Excellent Information. Thank you!

    #355868

    michael grady
    Spectator

    Hi Dave..

    Great write up. I wa wondering if you could make a specific recomendation. I have a 110 reef that I am uilding and have opted for the neptue apex controller. I do aleady have an MRC P skimmer and am very impressed with it. Is there a particular ca reactor that you know of that will interface with my Neptune Apex better than others? Also, sice I don’t have anything in the tank yet – just about to add water, when would I start the reactor up? Thanks,

    Michael

    #337437

    cr500_af
    Spectator

    Acroholic;647952 wrote: I see…your Apex has you program the high and low point, and the controller setpoint is midway between those values. The hysteresis is the equal amount above or below the midway point (controller setpoint).

    My RKE has me program the controller setpoint (midway point) and the hysteresis, then the RKE turns the CO2 on/off at the high or low point.

    2 different ways of doing the same thing.

    A small correction: Apex controllers don’t use hysteresis, they use If/Then statements. A pH controller could be used two ways:

    1. If pH > xx then ON

    In this example, your CO2 would come on at xx PLUS .1, since that is the first value that is above xx.

    2. If pH < xx then OFF

    In this example, your CO2 would turn off at xx MINUS .1, for the same reason.

    My reason for explaining this is that it doesn’t float .1 on BOTH sides of the value as hysteresis would. You don’t program a high point and a low point; you program one or the other.

    #331047

    Anonymous
      • Posts:6522
      @

    Crewdawg1981;643902 wrote: Okay, so I think I followed your primer to setup my MRC CR2, but I’m definitely having issues getting it dialed in. The biggest problem I’m having is keeping the pH down inside the reactor.

    I’ve got roughly 315 total water volume… though its likely more like 250 gallons of actual water. Mostly SPS frags at this point. A fair amount of frags at that. I’ve been doing a 20 gallon water change with Salinity every 1-1.5 weeks.

    I bought fine media… before finding out I probably should have gone with large… oh well. I filled up my first chamber and half of the second chamber, hooked everything up and let it run without CO2 for a few days. Turned on the CO2 at 60 BPM and then adjusted my effluent to ~50mls per minute and let it sit for a day. At 60 BPM, the pH within the reactor never went below ~7.2. So I adjusted the effluent to ~30 mls per minute at 60 BPM. This had the effect of lowering the pH to ~6.9-7.0. Let that stand for a few days as well and it never really got any lower. Finally, the most recent adjustment was to change the bubble rate. Currently I’m at ~90+ BPM and 50 mls per minute and the pH is 6.77.

    Am I doing this right? The solenoid never has to turn off because I had it set to 6.6.

    Here are the results of my testing:

    Last Monday

    ALK – 2.5 Meq

    CA – 350ish? (Seachem test… can hardly notice the color change)

    pH system – 8.10-8.20

    pH CaR – 7.20-7.40

    Last Weds

    ALK – 2.5-3 Meq

    CA – ~350ish

    pH system – 8.10-8.20

    pH CaR – 6.90-7.10

    Last Night

    ALK – 3.5 Meq

    CA – ~375-400

    pH system – 8.10-8.20

    pH CaR – 6.75-6.80

    Grant,

    At the settings you have, you should not have any issues with the pH of the reactor getting to a 6.6 or lower setting. MRC recommends using fine media, so you are good there as well. The CR2 is a dual chamber reactor, correct, with a reactor chamber and a passive 2nd chamber to pass the effluent through prior to it going back into the sump? And your recirculation pump is working? The top of the reactor has a pH probe port I assume, so the probe is inside the reactor water and you are not measuring effluent output in the sump, right? And I assume both your reactor chambers are filled with media?

    What kind of controller are you using, and is your probe calibrated? If I were to guess based on your information, I would guess that your probe needs to be calibrated or is defective. Because at a bubble count of 60-90/minute and effluent rate of 50-60 ml/minute, your reactor should be regularly coming on and going off. It should have no issues getting to a 6.6 setpoint.

    Your rector is a fine size for your system, and shouldn’t have issues keeping up with your tank’s ca, mag and KH demands.

    #337447

    Anonymous
      • Posts:6522
      @

    cr500_af;658649 wrote: A small correction: Apex controllers don’t use hysteresis, they use If/Then statements. A pH controller could be used two ways:

    1. If pH > xx then ON

    In this example, your CO2 would come on at xx PLUS .1, since that is the first value that is above xx.

    2. If pH < xx then OFF

    In this example, your CO2 would turn off at xx MINUS .1, for the same reason.

    My reason for explaining this is that it doesn’t float .1 on BOTH sides of the value as hysteresis would. You don’t program a high point and a low point; you program one or the other.

    OK…using scenario number 1 as an example, if the Apex has the CO2 come on at xx PLUS .1, does the Apex turn of the CO2 at xx MINUS .1, or at xx?

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