Need help with low PH(even after outside air into skimmer)

[stogie]

All,

I have ready randy's article on causes for low PH. I was originally running as low as 7.89 in my 120 bb tank. After running a air supply lead to the outside of house I am now up to 8.09-8.18.
The other tip Randy mentioned was to dose Kalk. I currently dose Kalk out of a 75 gal container with a Litre meter pump. It still doesnt get the PH any higher.
I have a Aqua controller Jr. to read my PH. I replaced my Neptune probe a month ago and have calibrated it 2 time since using it.
I airated a container of water directly outside and it did not raise the PH anymore.
Here are my current parms, All measured with Salifert test kits.

Temp 76.7 to 77.0
Alk 3.2 meq/L
CA 420
Mag 1200
salinity 34ppt

I know the Mag is a bit low and the Alk could be higher, but it does not appear out of wack. any Help would be appreciated.


Wes

[bertoni]

A pH of 8.1-8.2 is fine, in my opinion. What is the pH in the morning before the lights go on, and when did you take those measurements you listed?

[JamesJR]

what about aeration in the tank and around the house? Dissolved CO2
can really build up in a tank and lower the pH as a reef tank requires lots of oxygen. Just food for thought.

[stogie]

Right now, lights have been on for 3 hours. the PH is 8.09. I have run a tube to the outside of the house and feed the smimmer. I airated a contianer of water outside last night for 45 mins. Id did get cold and I took it inside and it read 8.04. I a container of water inside my house and watched the value begin to drop with inside air.

Thanks,
Wes

[David Grigor]

To me sounds like your chasing numbers a little too much.

If AM readings still above 8 and ALK levels are kept consistant to your posted reading of 3.2, I'd feel very content with your situation. Especially considering wintertime and house is closed up.

[stogie]

I was shooting for a more favorable PH # because I have read that PH directly impacts calcification. I have seen a decline in my coraline and in coral growth. Maybe I am just chasing the #'s.

[bertoni]

I doubt that a pH of 8.1 is causing a problem, if that's the lowest that it gets.

[jdieck]

If you are worried that 8.0 to 8.1 will afect calcification then increase your Alkalinity to the 3.5-3.8 range and your Calcium to 450 that will compensate whatever drop you might have.
I run my tank at 8.0 to 8.1 with alkalinity at 3.7 calcium at 430 and I wish corals to stop growing.

[stogie]

Ok, I will listen and stop hunt for low PH. I dont run a carbonate reactor just Kalk. I have unhooked my skimmer to do a threadwheel Mod to it. The skimmer was pulling air from outside the house. It has been unhooked for 5 hours now and the tank is down to 7.9. My pump has all kinds of precipitation on it and also noticed my heaters are white with precipitation. Is that an indication of a problem?

[JamesJR]

These types of precipitation are probably from Calcium carbonate from the water possibly getting saturated from the kalkwasser. If the pH was that low you wouldn't see this precipitation. (depending on what your pump is made out of) You should be able to clean it off your pump using vinegar or a very dillute muriatic acid solution. If the precipitate gets bad enough it can reduce the flow through pumps.

[jdieck]

That precipitation is unlikely if your PH was really that low unless your Calcium, Alkalinity or both were above the normal reanges with relatively low Magnesium.
So would I suspect that either your parameters testings are off or the PH is off.

From the article linked below here are some combinations were abiotic precipitation is more likely:

pH = 8.2
Calcium = 410 ppm
Alkalinity = 5.0 meq/L

pH = 8.2
Calcium = 820 ppm
Alkalinity = 2.5 meq/L

pH = 8.0
Calcium = 410 ppm
Alkalinity = 8.0 meq/L

pH = 8.7
Calcium = 410 ppm
Alkalinity = 2.5 meq/L

pH = 8.45
Calcium = 410 ppm
Alkalinity = 4.2 meq/L

Calcium and Alkalinity Balance Issues
http://reefkeeping.com/issues/2002-...ature/index.htm

A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH
http://reefkeeping.com/issues/2006-06/rhf/index.php

[stogie]

Thank you for all your inputs. I will see if I can test my parms with someone elses test equiptment.

Thanks,

Wes

[jdieck]

Good Luck!