Wow-the affects of house guests and pH
 

I had a dozen people or so over for the afternoon and supper and my pH alarm on my Apex started going off. I figured no biggie, just a bad reading or something, but it kept slowly going lower and lower. Finally It dawned on me that it was all the people in the same room as the tank and the build up of CO2. This is the first time I have had a large group over while having the advantage of continuous online monitoring. The drop was quite dramatic, .2 in just a couple of hours, but I was able to change the direction by opening the door. I never had any idea that the change would be quite that drastic.

I wonder if this is why people run their skimmer intake to the outside?

I just built an in-wall tank that backs into the HVAC room. I hope when I fire up the furnace for the winter that I don't have the same experience as you.. Yikes!

mine dropped from 8.14 to 8.05 within 2 hours
about 30 people where in a 700sq ft area dancing. We even had the doors open.

I remember going to a reef meeting in vancouver at someones house once and the same thing happened. We just opened the door there too but there was some frantic fumbling as to what to do before someone mentioned about getting some fresh air in :biggrin:

Funny you mention this .. I was just looking at this the other day and thought it was a neat idea:
http://www.bulkreefsupply.com/store/...raises-ph.html

Placed order, thank you, thank you.

From 8.1 to 8.0??? is that supposed to be a big leap?

Looks like nothing really. Mine drop and raise much more than that during the day and during the night, going from 7.9/8.0 to 8.3/8.4

Its a pretty significant drop for a 2 hour time span, more so than .4 over the course of a day.

What I meant is that it's probably not going to affect anything in your tank, as it is too little shift even in 2 hours.

It's very little, it's not even .1, it's .09

I actually never realized this could happen. Very interesting.

I guess I never experienced it because I run 2 big air stones in my sump. But good to know, and I won't be taking those air stones out any time soon.