Help setting up CO2 injection

[stygian7]

I've finally accumulated all of the necesarry components for injecting CO2 :), and need a little help setting it up. My question is this:
What do I set the pH controller to? Is there a general rule; my water comes out of the tap at 7.5 and stabilizes at 7.7 shortly after.
Thanks in advance,
Kevin

[jeff cannons]

Hi Kevin when you say PH controller is it the sort with digital display and an electrode if it is set it too your desired PH say 6.8 or 6.5 I would go with 6.8 myself then it will dose CO2 until it gets too that PH and then shut off then as soon as the PH rises it will dose again Good Luck with it !!!!!!
Jeff

[stygian7]

Yes it is the digital type with electrode (the milwaukee sms122 controller with a milwaukee regulator and solenoid). I guess I'll start adjusting the pH slowly over the next few weeks.
Thanks,
Kevin

[Paulio]

Kevin,

What is the carbonate hardness of your tank water? You can use the pH and kh to calculate your cos content. This will give you a target pH. Check this site out for great info on the pH/kh relationship and calculating co2 content.

http://www.csd.net/~cgadd/aqua/articles.htm

Paul

[stygian7]

Paul,
Thanks for the link; what a great site. My problem now is that I only know that my KH is below 20ppm. Can someone recommend a test kit that will give me more precise results?
-Kevin

[Qbal18]

With a KH bellow 20 i would not inject CO2 even with a controler. a KH of 20 is abot 1 DKH 1DKH=17.9ppm and with thatl evel to maintain 20ppm CO2 you would need a PH of 6.2
Raise your KH to 70 or 4DKH and set your PH at 6.8 you will then have 20ppm CO2 or 6.6 will give oyu 30ppm CO2
also with a low kh if for soem reason you do inject to nuch co2 you will not have your ph crash. bakeingsoda will raise oyur KH however i have never used it but know lots that have. if you cna get kent PH stable try it. it is what i use, works great and lasts forever. plus since it is just a more concentratred version of calcium carbonate you can still use that PH/KH/C02 chart.

[Biotypical]

Qbal,

1/2 tsp per 20gallons will get your KH up to 3 degrees or so. You may wish to try doing that.

Even so, I inject CO2 with a KH of 1-2degrees myself and have no problems. :)

[stygian7]

Right now I'm mixing R.O. and tap water set up on an automatic drip of approximately 40 gallons/day. If I eliminate the R.O. membrane and just use the sediment filters and carbon blocks I can get a KH of 60 ppm (3.4 degrees KH according to the calculator). By varying the proportion I suppose I can get anywhere in between as well.
Should I just eliminate the R.O., or should I shoot for a particular KH? Again any help is appreciated.
-Kevin

[Qbal18]

it is always easyer to go with a stable KH then trying to shoot or adjust for one. myself i would just go with your tap water a 60KH is pretty good. it is atable enogh that you will not have to worry about a crash and it is fin for your fis as well. and with a 60 kh set your Ph at 6.6-6.8 and you are good to go.

[Biotypical]

Stygian,

That sounds just perfect, I'd go with the non-membrane setup.