PH is low with high alk

jake2045 · Jul 31, 2015

Ok, I have a question about my ph I just calibrated my Apex and my tank is reading 8.00 now but was reading 8.29 before. My alk is 9.82 with Red Sea pro test kit. Can my pH be this low with my alk being 9.8?

hybridazn · Jul 31, 2015

Are you dosing to keep the alk up? Was this the ph reading during lights off?

Downbeach · Jul 31, 2015

8 isn't a bad number. Anytime your have to close your house up due to weather, you're going to get elevated levels of CO2 in your household atmosphere, and through your system's gas exchange lower your pH a bit. I wouldn't chase it.

twilliard · Jul 31, 2015

Excessive bacterial populations will make excessive co2

Randy Holmes-Farley · Jul 31, 2015

pH is controlled by the CO2 level and the alkalinity. If CO2 is high (as it often is in a closed home) then pH can be low even if alk is normal or high.

This has more:
Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com

twilliard · Jul 31, 2015

Well said Randy!
but a common question is "well what is raising my co2?"

Randy Holmes-Farley · Jul 31, 2015

twilliard said:
Well said Randy!
but a common question is "well what is raising my co2?"

Most often it is your own breathing in the room with the tank.

jake2045 · Jul 31, 2015

8 was with the lights on and I have been dosing Brightwell's Kalk+2, I'm also dosing vinegar and have not dialed in the right amount yet. I have a lot of bacteria in the glass.

twilliard · Jul 31, 2015

Oh another dosing dive, sad!
and what gave you the feeling you had to dose?
an over abundance of bacteria
either a much bigger skimmer to pull the blooms or stop the dosing. Well at least cut in half!

jake2045 · Jul 31, 2015

I started to dose vinegar because the NO3 and PO4 were both higher then I wanted. I started by adding it to my kalk mix like Randy dose and have done this in the past. Im currently lowering the amount and watching my number on the way down.My skimmer is pulling skimmate no problem. Just thought is was strange that my ph was on the low side and alk is 9.8.

twilliard · Jul 31, 2015

jake2045 said:
I started to dose vinegar because the NO3 and PO4 were both higher then I wanted. I started by adding it to my kalk mix like Randy dose and have done this in the past. Im currently lowering the amount and watching my number on the way down.My skimmer is pulling skimmate no problem. Just thought is was strange that my ph was on the low side and alk is 9.8.

That would be from your bacteria
there are much safer ways to control no3 and po4

twilliard · Jul 31, 2015

People don't agree with this but if you want to have an understanding of bacterial and organic populations do my ph test. Backwoods chemist per say.
want more info on it PM me

Randy Holmes-Farley · Jul 31, 2015

jake2045 said:
I started to dose vinegar because the NO3 and PO4 were both higher then I wanted. I started by adding it to my kalk mix like Randy dose and have done this in the past. Im currently lowering the amount and watching my number on the way down.My skimmer is pulling skimmate no problem. Just thought is was strange that my ph was on the low side and alk is 9.8.

The breakdown of the vinegar to CO2 will help pull down the pH, but it is often only a secondary to room CO2. In any case, pH 8.0 is fine.

neuwave · Jul 31, 2015

Don't be too surprised. Randy's right. Increasing amounts of CO2 from an enclosed home will lower your PH. Here in Florida most people keep a tight seal on their homes due to the relentless heat and humidity. I've gone to others hobbyists homes where their Alk was 10-12 and the Ph was at 7.8. Opening a window, running your skimmer air intake to the outside air, build a CO2 scrubber and setup a reverse refugium light cycle can help with a CO2 issue. These are just some options.