C02 And Kalc Effect On Ph

[craigg]

CAn anyone confirm the following statement please as I've finally got my Octopus computer working and all the probes, so I want my octopus to control input of water from both my Kalkwasser reactor and Calcium Reactor.


C02 (Calcium reactor) - Lowers PH?

Kalkwasser - Raises PH?

I could be wrong about C02 but I'm positive on the Kalkwasser cause I've just added some and my PH has shot through the roof.

Craig.

[lex]

yes i belive this is correct <_< :huh:

[tuan]

Yes - basically, calcium reactors uses CO2 to make carbonic acid (lower pH) to dissolve the media. Limewater on the other hand is a hydroxide, ie. adding Hydrogen ions (simply speaking, pH is a measure of H ions) and so is at high pH. Saturated limewater has a pH of around 12.5.

Here's a very useful article by Randy Holmes-Farley: How to Select a Calcium and Alkalinity Supplementation Scheme (http://www.advancedaquarist.com/issues/feb2003/chem.htm)

[craigg]

muchus gracias

Got say since accuratly knowing what my PH was (not using c%$p test kits) I was:-

a: Shocked
b: scared.

But now I can maybe stabalise something that I never knew I had a problem with.

oh the joy.

Craig.

[narthur]

Craig i feel the same about test kits and PH you just don't know where you stand...errr good move getting the Octopus where did you get it from and was it expensive?

[craigg]

Nic I had one for ages but really struggled to get the probes to calibrate, so it went back for repair and was told there was nowt wrong with it. Anyway when I got it back and plugged it in it blew up, so it got sent back again and they wanted to charge silly money to fix it, so I wrote it off.

Anyway luck would have it someone on here had one for sale on Ebay, so I made him an offer quick and did a deal.

Octopus, all 4 probes and 12 X-10 control devices, comms link to PC, battery backup all for £350.

So all my old stuff I still have spares of as well, so I now have about 20 X-10 devices and 2 spare probes for each test.

Luckily this ones works a treat.

Craig.

[narthur]

pretty lucky there craig... do you know anyone who just uses the Ph probes like say the American precision are they reliable and can you just calibrate them once and them leave the probe in the tank??? nic

[buster617]

Limewater on the other hand is a hydroxide, ie. adding Hydrogen ions

Its actually the other way around. Carbonic acid from the calcium reactor will add the hydrogen ions to lower the pH. Kalkwasser adds hydroxide ions which will in effect neutralise and reduce the hydrogen ion concentration to raise the pH.