Calcium reactor help needed

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Good day.

So after almost loosing everything in my tank, its stable now. Time to set up the carx again. Is there any people who can advice me on how to propper and successfully set it up? Please guys.
As usual, I’ve done a load of reading and can’t find any definite answers. I am so confused about how to set it up. Some articles state that you should use the CO2 rate to adjust for alkalinity changes( increase CO2 rate for more desolved or decrease CO2 for less desolved media to alkalinity requirements) and some say use use effluent rate to counteract changes.

Please, I know theres a whole bunch of reefers who’s got a firm understanding about carx, and I really don’t want to loose my inhabitants again....
 
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Hi Theo, I feel your frustration, as a carx can be a blessing as well as a curse. I have recently come very close to tossing mine and simply going the doser route. However, once i got the problem sorted, i am again reluctant to change, as the stability it gives me is unparalleled.
This is how I set mine up:

Step 0:
Even before setting up your carx, the most important thing to take into consideration is what you need the carx to do, i.e. replenish calcium alkalinity and other minerals and trace minirals as used by calcification and ither biotic processes.
The best way to determine this need is to use alkalinity consumption of your tank, done by measuing alkalinity without the calcium reactor set up over a few days.

Step 1:
You have a feed pump for the carx, the actual reactor itself, a CO2 tank and controllable delivery method of CO2 to the rectir by means of solenoid and needle valve and bubble counter.
You mentioned you have a pH controller running your reactor? They do make things a LOT easier.
Put a control valve on the hose feeding water into the reactor, set up reactor with probe from pH controller and an outlet for the effluent also with a control valve on, as well as the CO2 supply. These should all be pretty standard and included in the instructions that came with it. Remember to always have a non return valve on the CO2 feed line.

Part 3
Keeping the needle valve closed on the CO2 feed line, Let the reactor fill with tank water via its feed pump and let the effluent run out.
Set the controller to a pH of around 6.8, which should open the solenoid when pH in reactor rises above 6.8 allowing in CO2 and close it when pH reaches the set point.

Part 4
I guess from here onwards is where your actual question gets answered, apologies for the basics if you already had them under the belt.
Close the valve on the water feed line to reactor until you get a slow drip of about 3 drops per second. Now close the valve on the outlet of the reactor until you get a steady drip of about 2drops per second.
Open the needle valve on the CO line to reactor until you get about 1 bubble per second in the bubble counter.

Part 5
Measure the alkalinity of the effluent from the reactor and give it two days then measure your tanks alkalinity.
Use an on line calcium reactor calculator to determine whether you should increase the effluent miniral content. I use this one: http://reef.diesyst.com/reactor/reactor.html

Part 6
To adjust the reactor contribution to system mineral replenishment, the real fun part, can be achieved in any of the ways you mentioned in your original post.
A lower pH at the same drip rate will cause an effluent with a higher alk. A faster drip rate will mauntain the same effluent alkalinity but add more alk as a function of volume dosed. However, this will only be achieved as long as input rate of CO2 (bubble rate) is also increased together with the flow rate, facilitating ease of maintaining the pH set point in reactor.
 
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@irie ivan , I thank you kindly sir. I appreciate your input on this. I’ve lost about R3000 worth of fish due to this thing so needless to say I am very scared and skeptical about turning it back on.

If you don’t mind, just to clarify.
-I should test the alk to get a set result beforehand? I was thinking of getting a exact time to test this daily and teat it for about 2 weeks before restarting it, thus making sure I erase any other influences.
-For it to give out more alk I should adjust the CO2 input?


The previous time I had it running:

I always noticed that ca and mg was in check, ph was at higher end and alk was always at the lower end. I turned up the effluent rate to maintain the alk, and next thing was ph shot through the roof. So how do I set it to maintain desired ca and mg levels, while getting a perfect balance between alk and ph?
 
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Theo it is beyond me how a calcium reactor can raise tank pH, except for incorrect media and O2 instead of CO2 being in the cylinder.i read your thread and do not see how, and its perplexing that when you removed the carx thungs seemed to come right.
To answer, for it to give out more alk, you just lower the pH set point on the controller, if you want to keep the same effluent and CO2 rate. A lowered pH causes higher dissolution rate of the aragonite media in the reactor yes.
The reason you test the alk in tank beforehand is to get your consumtion rate.
You dont have to test effluent alk initially, I do cause i want and need to know.
Its fine to test it after two days when you are about to start making corrwctions.
To answer your last question, you set it to replenish alkalinity consumption to give you a stable alk and Ca and mostly Mg and Sr and some other trace elements.
As for pH, carx will drive overall system pH down over time, NOT UP. Various ways to stabalize pH is reverse lighting cycle in sump, dosing kalkwasser and or aerating the sump
 
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@irie ivan , thanks for your great input. Do you think it would be wise to dose kalkwasser via topup with carx?

I also don’t understand why the carx increased the ph. Since I switched it off it stabilized. I use reborn, which is a good media, and mg is zeovit. It has to be CO2 in the cylinder otherwise the internal carx ph wouldn’t be lower than feed water ph. Ive tested every possible thing that could influence the ph and that’s the only thing which I changed, is switching off the carx.
 
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@irie ivan , thanks for your great input. Do you think it would be wise to dose kalkwasser via topup with carx?
Yes, as long as there is a safety check in place, like the top up on a timer or a valve to drip instead of pour in kalk
 
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