# Milwaukee MC122 pH Controller setup help



## Bobbybills (Nov 30, 2015)

payluder said:


> I would like to know what setting I should use with my co2 tank to get my ph stable at 6.6 Do I turn the nob to be around 6.6 and what switch should I use above or below? when my lights are on and co2 is going my ph reads 6.8 and right before I went to work 12 hours later when lights was off my ph reads 7.1. Please help
> 
> thank you


Assuming the CO2 setup has a normally closed solenoid, set the switch to above and the PH knob to 6.6. The relay will energize the solenoid and open when the PH rises above this set point, releasing CO2 to lower the PH.

PH should rise as CO2 is consumed by the plants when the lights are on, and should fall when the lights are off as CO2 is released back into the water through respiration, from plants and fish. Is the 7.1 reading right when the lights turn off or after they have been off for the night?


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## payluder (Feb 3, 2016)

Bobbybills said:


> Assuming the CO2 setup has a normally closed solenoid, set the switch to above and the PH knob to 6.6. The relay will energize the solenoid and open when the PH rises above this set point, releasing CO2 to lower the PH.
> 
> PH should rise as CO2 is consumed by the plants when the lights are on, and should fall when the lights are off as CO2 is released back into the water through respiration, from plants and fish. Is the 7.1 reading right when the lights turn off or after they have been off for the night?



The 7.1 reading was after 12 hours of lights being off in the morning. Ah ok from what I was reading on google search I thought the switch was suppose to be set to below for co2 and above for dosing. But I guess it make sense to set it for 6.6 and have it set for above so if it goes over 6.6 the unit will turn on the co2 to lower the ph back to 6.6 right?


thank you


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## Bobbybills (Nov 30, 2015)

payluder, you should be looking into why the PH is rising at night. What is the GH/KH? What is the bio load? Substrate? PH should definitely not go up at night in a planted tank unless you are losing CO2 through off-gassing or aeration. If fact, some use aeration at night to keep the PH from dropping too low.

Other than that, perhaps a buffering issue.


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## payluder (Feb 3, 2016)

By aeration do you mean by me positioning my lily pipe high enough so the flow is making ripples on the surface? I recently did this for better gas exchange but if this effects my ph a lot then I can limit the surface ripples.


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## Bobbybills (Nov 30, 2015)

With CO2 tanks, you do not need gas exchange to supply Oxygen, the plants should do that during the day when the lights are on. What is you light source? How old is the tank? Why did you think you needed gas exchange? All of this matters in order for you to be able to properly troubleshoot.


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## payluder (Feb 3, 2016)

Bobbybills said:


> With CO2 tanks, you do not need gas exchange to supply Oxygen, the plants should do that during the day when the lights are on. What is you light source? How old is the tank? Why did you think you needed gas exchange? All of this matters in order for you to be able to properly troubleshoot.


Hi Bobbybill

My tank is 5 months old I was dealing with algae but seems to be under control now. Its heavily planted and I have about 50 crystal black shrimps and 5 oto and 2 scarlet badis. I removed my air pump so tank look less crowded so I thought making ripple will help with getting oxygen in the tank for the live stock. I have a 24in planted + 24/7 hanging 6 inch above the tank near the back and another LED light that is weaker towards the front for my hc and hair grass carpet. Light on a 3hr timer and off for 1 1/2 hr and back on again for 3hr so I can enjoy the tank after dinner. I'm not too worried about too much lighting since I have tons of floating plants.


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## Bobbybills (Nov 30, 2015)

Are you in Australia? Joking aside, it looks like everything is under control despite the slight ph rise at night. Did you have the air pump running at night before the CO2 controller was installed?

How about KH


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## payluder (Feb 3, 2016)

Bobbybills said:


> Are you in Australia? Joking aside, it looks like everything is under control despite the slight ph rise at night. Did you have the air pump running at night before the CO2 controller was installed?
> 
> How about KH


LOL sorry I dont know why the photo is upside down. I had a air pump but took it put a week before installing the ph controller. Its my second day having the controller. 


After you mentioning about ph buffering and it made me think about how I setup my tank and remembered that I added a bag the size 4inch and 3inch thick of crush coral in my canister which is suppose to stable at 7ph. I think this is the reason my ph is going up when lights go out and co2 is off? If recommended to be remove I will do so.


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## Bobbybills (Nov 30, 2015)

payluder said:


> After you mentioning about ph buffering and it made me think about how I setup my tank and remembered that I added a bag the size 4inch and 3inch thick of crush coral in my canister which is suppose to stable at 7ph. I think this is the reason my ph is going up when lights go out and co2 is off? If recommended to be remove I will do so.


Freshwater 101 would say to remove crushed coral from the canister filter unless keeping African Cichlids. KH around 3-5 and you are good to go.


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## payluder (Feb 3, 2016)

Bobbybills said:


> Freshwater 101 would say to remove crushed coral from the canister filter unless keeping African Cichlids. KH around 3-5 and you are good to go.


Thank you I will remove the bag and buy a KH tester. Very good information you are giving me and Im starting to really understand all this now.


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## Bobbybills (Nov 30, 2015)

What is your source water?


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## bill984 (11 mo ago)

Thank you. Just set up my controller and had same problem setting it up.


Bobbybills said:


> Assuming the CO2 setup has a normally closed solenoid, set the switch to above and the PH knob to 6.6. The relay will energize the solenoid and open when the PH rises above this set point, releasing CO2 to lower the PH.
> 
> PH should rise as CO2 is consumed by the plants when the lights are on, and should fall when the lights are off as CO2 is released back into the water through respiration, from plants and fish. Is the 7.1 reading right when the lights turn off or after they have been off for the night?


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