Aeration and PH

[Esquare]

Ok, as part of my daily home/reef work, I’ve been reading up on how aeration effects ph. According to the articles, low ph (such as mine 7.83) can sometimes be raised with aeration as long as the air used to aerate is not high in carbon dioxide. My question is, wouldn’t a protein skimmer give you all of the aeration that you could use? If not, how can you improve on the amount of air that a skimmer introduces into the water? My cal and alk are fine (415 and 10.9). I don’t mind using gadgets and gizmos to alter the ph (I happen to be the gadget and gizmo king in my area) but I want to make sure that I am addressing the cause and not a symptom.

Any assistance is appreciated.

[bertoni]

A skimmer can perform a lot of aeration, and tanks with skimmers often don't show any improvement in pH with more aeration. A lot depends on the type of skimmer and the size of the tank, though. I suspect fresher air works better in most cases.

[Esquare]

I wonder if an extended air line for the skimmer running outside of the house would effect the skimmers performance? The sump and skimmer are in the basement.

It's a RS-100 skimmer on a 54 g dt with approx 125 gal of overall vol.

[bertoni]

The extended line might reduce the air draw of the skimmer, unless a pump were added. Sometimes, the line doesn't help, likely because the inside air is too high in carbon dioxide.

[Esquare]

I think that I will boserve it for a while to see what happens. I am trying to make sense of my ac3 graphs and can't seem to see a pattern in the ph swings. it goes from 7.6 to 8.02 and anywhere in between. Could it be that the tank hasn't been setup long enough for it to stabilize (2-3 months)?

[bertoni]

I don't believe the 7.6 number very much. I would check for electrical interference and similar issues. Is the probe kept in the dark?

[rbursek]

I have the same problem, yes the skimmer adds alot of DO, but if the air in your basement is high in CO2 it is just adding it. Light cycle alters PH, higher at the end and lowest just before the come on, all thingsbeing equal, photothynisis thing. I to am going to run my air tube of the skimmer to outside air, just have not done it yet, and yes there maybe less air in it do to the lenght of the tubing, may run larger tubing and the neck it down at the skimmer.

[Billybeau1]

Take a cup of your tank water and aerate it outside for an hour or so and measure the pH before and after. If you see a dramatic rise, it is indeed CO₂ suppressing your pH level.

Some have seen good results in running outside air into their skimmers. But like Jon said, you will probably need a pump.

[Esquare]

I did the areation test I found listed in one of the articles and saw about a .15 bump. The probe is in my sump between the baffles (good water flow) about 1 inch from the temp probe. I'm at 7.82 right now and this past week has ranged from a high of 7.88 on 5/8 to a low of 7.6 yesterday. It had been running between 8.05 and 7.8 for the most part, maybe the 7.6 was an aberation as Jon suggested.

I wonder if it's possible to filter the air going into the skimmer such as a charcoal filter or something similar? I don't know if it's feasible to filter it enough to make a difference.

[Esquare]

Oh, forgot, th eprobe is in a dim/dark area.

[Billybeau1]

When is the last time you cleaned and calibrated your pH probe ?

[Esquare]

Never, but it's only been in there for about 2 months.

[Esquare]

I calibrated it when I installed it.

[Billybeau1]

You may want to do it again to be sure. Use good quality calibration fluids like Pinpoints 7 and 10.

I calibrate my probe about every 2 months.

[Esquare]

Every 2 months....yeah sounds like a good next step. Thanks for the info.

[Billybeau1]

Good luck

I will be heading your way in a couple of weeks. Gonna do some walleye fishing out of Port Clinton. Save some good weather for me will ya.

[Esquare]

Thanks again.

HAHA good weather? if you don't like it, stick around it will change in a few minutes!

[Esquare]

Well I rinsed off the probe with ro water and that has it at 7.91. I'm waiting for the lfs to open (Thurs) to get some calibration solution.

In researching ph, I came across a formula to measure co2

CO2 (in PPM) = 3 * KH * 10( 7-pH )

Don't know how accurate this is but according to it, I'm at 4.5 ppm co2. Do you know how accurate this method of measuring co2 is? I was thinking about trying different filters for the air inlet of the skimmer, such as carbon, ca co3 etc but it will be less helpfull if I can't measure co2.

[Billybeau1]

You should soak your probe tip in either vinegar or hydrochloric acid for about an hour.

I doubt that formula for CO₂ is any good but I don't have the chemistry expertise to tell you why.

[Esquare]

10-4, I'll soak it when I get the solution. I'm up to 7.95 now.