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Discussion Starter · #1 ·
I am setting up my calcium reactor. I don't know if its just that I am tired but these instructions for my pinpoint PH controller suck. I have it calibrate. I want it to controll my CO2 solenoid. I want it to have a centerline of 6.8 with a range of +-4. 6.6-7.0 according to the MRC instructions. The controller has a slide switch on the right that has three settings. HIGH, Read, LOW.
Do I set the switch to HIGH, then put the centerline to 6.8. Then adjust the range? The instructions aren't really clear where to put the slide switch.
 

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Put the set point screws both at the minimum value, then turn the center value to a whole number (not entirely necessary just makes the math faster) then adjust the range until the difference between the high and low value are .4. Once you have that -- switched on high, turn the center value up until it reads 7.0. These settings will turn on [email protected] and turn on [email protected] then shut either off at 6.8.
 

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Your reactor will run better with a range of +0.05 pH units, so that it runs with a 6.7 as the center pH value, and up to 6.75 and down to 6.65... even then you will have range drop-outs down as low as 6.5 depending on how high you have your predsure set for the regulator and what your needle valve adjustment is (in terms of bubbles per minute). Although the suggestion by Wharyat is correct, thes setting are a better starting point and will put you closer to being on the money quicker as far as your tank Ca++ and alk values go. Even with this setting, you will go through lot of aragonite reactor media in a fairly short time period. Running at much more than this narrow a range begins to waste CO2 and ends up spilling the excess dissolved CO2 into the tank, causing issues with your tanks's pH and driving your average pH down to the sub 7.0 range on a regular basis, especially when the lights are out. Unless your tank is really heavily stocked with hermatypic corls and you have a problem keeping your Ca++ and alkalinity values at acceptible ranges, you will need less CO2 and have a more consistant delivery by using a less wide range and centering on a 6.7 value. This may mean leaving your range setting at the minimum setting and hoping that the sensitivity on your potentiometers is good enough to operate at this value, but you should not have any problems once the controller get to equilibrium with the system. You need to monitor the tank's pH as well, at a point that is upstream from the effluent for the reactor. Make sure to use a separate pH meter for this, well away from the efflent mixing area for the reactor's effluent. This wil allow you to keep from poisoning your fih nd misc other critters with an accidental overdose of CO2. More on this if you need it.

How many corals DO you have? Clams? How old and how big are the colonies? BB or sand? Which size reactor, and do you have a second column? More info on your settings and the tank please ! :D

HTH
 

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Discussion Starter · #4 ·
I have the RK2 to monitor PH. Thanks for the help. I am printing this out and I am going to run downstairs and start filling it with water and see if I can get it working.

One more question. In the manual it says to put the pressure at 10 PSI. Does that mean you adjust the main CO2 tank valve down so the pressure is 10 PSI? I know the needle valve is for the bubble counter.
 

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I'm not sure about the 10 PSI. I run my regulator at 20lbs then adjust the needle valve so it is at about 2 bubbles per second (since the pH is controlled, bubble count isn't really an issue) that way it's not overwhelming the circulation pump and pretty quick at raising pH.
 

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I just realized my suggestion on CO2 flow wont work for you if you're measuring effluent pH. I've modified my CR2 so I can run the pH probe in the first cylinder so my controller can see the pH change before wasting CO2; it takes a lot longer for effluent pH to change.

For CO2 flow, you should follow the instructions and Tom's advice.
 

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I just realized my suggestion on CO2 flow wont work for you if you're measuring effluent pH. I've modified my CR2 so I can run the pH probe in the first cylinder so my controller can see the pH change before wasting CO2; it takes a lot longer for effluent pH to change.

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...and for effluent measurements, the effluent must be running to see the changes at all. This will determine where you place the probe, ie. the probe holder for the controller. If your effluent is running at a set rate at around 50-60 ml/min, then the effluent pH should be close to what your reactor chamber pH is at any given time, or if you use the recirc line to place the probe holder, you should see pH at what the reactor chamber is as well. If you're measuring pH with the probe at the effluent, then you will want to measure it as it is just leaving the reactor chamber, and in two column reactors, you will want to measure pH between the first and second columns. So long as you are consistent in your measurements (from day 1), it really will not make that much difference where you measure, so long as you allow for equilibrium to occur before making changes to settings, and this is slow regardless of you go about measuring your pH in the reactor. CO2 must:
  1. bubble into the recirculation water
  2. dissolve in the recalculating ASW
  3. CO2 must react with water to form carbonic acid
  4. carbonic acid must dissociate
  5. ion specie formation must occur AND COME TO EQUILIBRIUM (each step has its own rate constant in both directions COOH <--> COO- + H+ <<SUP>H2O</SUP>> H2CO3 <---> H+ + HCO3- <---> H+ + CO3-- <<SUP>Ca++</SUP>> Ca++ + CO3--<SUB>dissolved</SUB><--->CaCO3<SUB>SOLID</SUB> )
  6. any change in the rates of dissolution of CO2, concentration, or reactivity with other ions will change the reaction rates, so equilibrium may take days to stabilize.
  7. wait 2 to 3 days after each change you make (effluent flow, CO2 bubble rate, pH center or range changes) to see the final results, and get a good alk kit for testing (I still recommend the Salifert, especially now that they have a standard with the kits to test your technique)
If your probe is placed in the reactor cylinder, it will detect changes more quickly, but in the big picture, this is of little consequence, as the reaction rates at rate-limiting points of the equilibrium are so slow that it may be of little benefit to be able to see the changes a few minutes sooner, rather wait for the final effect as measured in the effluent at a point of stability (this means wait for the time to pass). Search for Whiskey's or Joe Henderson's or Mike Soda's threads on setting up their reactors, there is a lot of info there, as well as a pix of the probe holder in place if your reactor is NOT one of the few that has a probe holder in the reactor chamber. The advantage of using a line placement as opposed to chamber placement for the probe is that when you need to remove the probe for cleaning and calibration, you only need to turn off the valves for the holder and allow the reactor to continue circulating at pressurization to remove the probe, rather than turning off the reactor to remove the probe, requiring reestablishing equilibrium again.


Post questions here if you have problems, many folks on TRT are using reactors now; great for systems with high Ca++ and alk demands, and they make managing the system much easier in the long run.


Probably best to start out running the effluent wide open initilly to make sure there are no leaks in the system, then start the reactor with a very slow bubble rate (2 or 4 BPM) for the CO2 gas just to get the system pressurized, although at the BPM, the controller my not turn off CO2 gas for a while due to failure of the low BPM rate to significantly acidify the reactor recirculation loop water. Gradually increase the BPM until the solenoid starts cutting off the gas at a suitible cycle time (remember: go slow, it takes a day or so for changes to fully affect the reactor, but final delivery will usually be somewhere around 2 to 8 BPSec rate depending on many variables), which will change as the system comes to equilibrium, so this may take a few days to get to a good reactor running point.


HTH
 

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Discussion Starter · #8 ·
I actually have a T adapter so I can measure PH in the effluent between the two chambers. Its a dual model. Thanks for all the good advice. I am exhausted right now so I am going to read more into this tomorrow when I have some sleep. I set the reactor up without any water or co2 so I just have to start it up and make adjustments tomorrow.
 

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I actually have a T adapter so I can measure PH in the effluent between the two chambers. Its a dual model....
Pix please, not sure I am following this, but I think I know what you're speaking of. Just want to make sure we're on the same wavelength.
 

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Discussion Starter · #10 ·
Here is some information about my reactor. It is a CR-6 from my reef creations. My tank has a good amount of SPS and a few large LPS in it. My birdnest is about the size of a volleyball and I have some other ones that are good size. Not as large. You can see the T adapter in the last picture. The probe is not inserted yet since there is not water to keep the probe wet yet.

Can I use regular airline tubing to get the CO2 to the reactor? I have some tubing that came with it but I want to make it longer. I have the colored airline tubing that feels more like rubber from petco not the clear plastic tubing?

I am going to set my pinpoint PH controller tonght. I am going to put both the range and the centerline dials to minimum. Then I am going to switch the the slide lever on the right to HIGH. I will turn the centerline dial to a whole number. I am going to make this with a range of .05 like Tom suggested. So I will turn the range dial up until it is .05 above the whole number. Then I am going to turn the centerline value up to 6.75. Then I switch the slide swith back to read. I don't need to turn it to the LOW selection at all correct?


 

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Discussion Starter · #11 ·
Another thing. My regulator came used with my reactor. I think it came from MRC it looks exactly the same as the one on this page.
http://www.myreefcreations.com/caaccessories.htm
it says the pressure is preset. Does that mean I can't change it? If I am correct, the needle valve adjustment is the valve on the left with the + or -. There is a flathead slot on the bottom of the regulator, if it is preset is that how you would set it if you wanted?
I had a 5 lb. bottle. I took it in to get exchanged. When I hooked my regulator up to it today it says less than 1000 PSI. Is that right or shouldn't it be a little higher?
 

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Another thing. My regulator came used with my reactor. I think it came from MRC it looks exactly the same as the one on this page.
http://www.myreefcreations.com/caaccessories.htm
it says the pressure is preset. Does that mean I can't change it? If I am correct, the needle valve adjustment is the valve on the left with the + or -. There is a flathead slot on the bottom of the regulator, if it is preset is that how you would set it if you wanted?
I had a 5 lb. bottle. I took it in to get exchanged. When I hooked my regulator up to it today it says less than 1000 PSI. Is that right or shouldn't it be a little higher?

Yep, if its preset to 20, you cant change it, but I would think 20 is fine. the valve on the bottle should be all the way open so it does not leak around the stem.
 

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duplicate posts during edits...
 

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duplicate posting during edits :eek: )
 

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:)eek: must be a system problem-- duplicate posts )

Your plan sounds good so far.
 

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I have one of the CR-6 reactors and it provides plenty of Ca and alk for a 180 USG tank with heavy pop densities of hermatypic organisms, and I still have adjusment on the up side to make the concentrtions even higher (or to meet greater demand) if the need be. You'll be very happy with this reactor.

The Genex regulators woek quite well, and you'll have some adjustment for the working pressure for the regulator as well. The large black triangular handle will control your working pressue, when installing the regulator on the tank, make sure to include the nylon washer between the tank nozzle and the regulator, then hand tighten it down while the valve on the tank is closed. You might want to use a wrench to turn the attaching nut for the regulator another 1/8 to 1/4th turn, but you do not want to turn this nut down super tight, just enough to stop any air from leaking. You can test for this by using soapy water (a few drops of dishwashing liquid in an ounce of tap water is fine) bruhed over the nut, then opening the tank valve just enough to presurize the regulator, then watching for bubbles (leaks) at the attachment nut for the regulator, a smart thing to test for, as CO2 can be potentilly a poison at concentrations above 10%... :eek: ... and alhough most of the CO2 is going to be converted into alkalinity and stay in the water column, excesses in the tank will bubble off into the room, so make sure that the room is well-ventilated while adjusting the regulator.). You will need to back the black working pressure handle off until it just starts feeling loose (do this before addaching the regulator to the tank, this will be the point of working pressue = room pressure), then attach the regulator to the tank, make sure it does not leak, and gradually tighten the handle until you see the working pressure dial move up to between 15 and 25 lbs ( you should be able to adjust this low-pressure regulator to exactly 20 lbs, but this is a good working range if yours will not measure this, but I am sure it will).

This will have established your working pressure: the flow rate can be controlled with the needle valve. Try shutting it all the way down initially, then open it up just enough to get your very slow initial CO2 flow rate (2 to 4 BPM, but this will be too slow, but it is a start) to pressurize the system without cycling the solnoid. CHECK FOR LEAKS: this may take a while to see any leaks, and you might want to increase the bubble rate to 2-4 BPSec, but this higher rate will start cycling your solnoid, so the system may not be under pressure while you're checking (when the solnoid cuts off the gas). Just watch for leaks, they alays seem to show when you're not watching. Make sure to include a check valve for the CO2 gas between the water column and the regulator, this will stop ASW from backing up into the regultor, which will pretty much ruin it over time should this occur. It's a good thing to put the tank and regulator higher than the highest point that water will be flowing in the rector for the same reason... :squint:

More later if you need it.

Your plan sounds good so far.
 

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I notice that your probe holder does not have any shutoff valves, you might want to go to Home Despot or Blowes and get a pair of JACO fittings that has the valves as part of the fitting (about $5 USD ea ) so that all you have to do to borax test or clean and recalibrate your probe is to cut off the two valves at the fitting to prevent siphoning while you perform the cleaning/calibrtion/testing of the probe rather than shut off the reactor (and you will still get siphoning) then have to wait for everything to come back to equlibrium...
 

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Discussion Starter · #20 ·
The calcium reactor now has water in it. I have it running full out. I am going to cut back the output here with the needle valve to about 50-60ml. Then I am going to start the CO2. I have the controller set and the probe calibrated.
 
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