Ph keeps settling down much lower

[seastar]

For the last couple of days I have dosed Alk in my (currently coral only tank as my fish are in a QT recovering from marine velvet) and my Ph rises to 8.25. By this morning is was right around 8 and by mid afternoon it settles back in at around 7.93-7.94. I don't have a ton of coral in here yet so Im not sure what's going on, any ideas? Very minimal coralline on anything other than my black/plastic corner overflow.

Temp: 78.6
Sal: 1.026
Ph: 7.94
Alk: 8
NH3: 0
NO2: 0
NO3: 15ppm
PO4 0.03
Cal:500
Mg:1360

 

[LostInTheDark]

Nothing wrong with a PH around 8. This time of year with all the windows closed the carbon dioxide builds up in the tank and lowers PH.

 

[seastar]

I just happen to live in Florida and you reminded me its a lovely 74 out today! Office windows now open!

So it would make sense for it to keep lowering itself like that given that my house has been all buttoned up?

 

[LostInTheDark]

As long as your PH is around 8 its not one of those numbers you want to chase. Are you manually dosing ALK? A doser might keep it stable. I've seen tanks with monitors that will fall to the low 7's when there is a winter time party with all the windows closed. I had a similar issue and solved it by running my skimmer air feed through the wall for outside air. I wouldn't worry about it much with your numbers.

 

[seastar]

I am manually dosing until the end of the weekend when I get my BRS 2 part dosing kit installed. So looking forward to getting it up and running.

I was asking now I guess because I was surprised now much it dropped in one day. I saw people trying to target 8.1-8.3 and having great success and I was hoping to piggy pack off of that experience a little.

 

[Diesel]

Hmmm.......
What kind of test kits you use?
What do you use to dose ALK?
What's the size of tank we talking here, and do you have a picture?
Any powerheads/wavemakers in the tank?

 

[LostInTheDark]

You can raise your alk some and that would raise ph.

 

[seastar]

Hmmm.......
What kind of test kits you use?
What do you use to dose ALK?
What's the size of tank we talking here, and do you have a picture?
Any powerheads/wavemakers in the tank?

I am using the RedSea test kit for Alk, my Ph I am measuring through my Apex.
I am using RedSea Reef foundations for Alk.
75gal tank with a 30 gallon sump (photo: I thought you'd never ask!)
two jebao's as far as powerheads are concerned.

FWIW: I opened my windows and it's slowly crawling back up, currently 8.02 after about an hour.

 

[Diesel]

Looking nice!
Windows always work, as one of your jeabos pointing to the surface of your water in order to have more surface movement.
You can also hookup your skimmer to a piece of tubing and suck the air from outside.
I see you have a light at your sump too, try running it for a longer time.

 

[LostInTheDark]

FWIW: I opened my windows and it's slowly crawling back up, currently 8.02 after about an hour.

Sometimes the easiest solution is the best solution.