Why does pH drop at night?

[hazmat]

I did a search and couldn't find an answer but I'm sure its out there. So can someone explain to me why it drops at night?? And is it any big deal?

 

I tested my water first thing this morning because I found one of my clowns dead. My pH was at 7.8. Wondering if that was the reason or something else. Also, does Chaeto affect pH? I'm getting some to put in a soapdish in the main tank.

 

Thanks

[Laura6686]

I did a search and couldn't find an answer but I'm sure its out there. So can someone explain to me why it drops at night?? And is it any big deal?

 

I tested my water first thing this morning because I found one of my clowns dead. My pH was at 7.8. Wondering if that was the reason or something else. Also, does Chaeto affect pH? I'm getting some to put in a soapdish in the main tank.

 

Thanks

 

Hi:

 

I have not read the whole article yet but it addresses why pH drops at night. I am going to bookmark it for later read:

 

http://www.reefkeeping.com/issues/2004-09/rhf/index.php

[Scott Riemer]

Generally speaking, 7.8 is an acceptable pH. The question is, do you know for certain it dropped. Meaning: do you know what the pH was last night?

 

Here's an article about pH that contains a lot of information but does not address your specific question.

 

http://www.advancedaquarist.com/issues/june2002/chem.htm

[hazmat]

Thanks guys!

 

I'm off to read!

[hazmat]

Those 2 articles are written by the same person and have the same info! Except the first one does address why it drops at night.

Good reading. I think I'm being concerned about nothing. As stated 7.8 is low normal.

 

Now question is...what is everyone keeping their alkalinity at? My dKH is 9.

[The Propagator]

The simple answer:

Biochemical reaction within. The bacteria react with light and raise PH. when the lights go out the PH engine takes a breather.

[yardboy]

Simpler answer is that when the lights are on algae are producing oxygen and consuming carbon dioxide. At night with the lights off they consume oxygen and release carbon dioxide. Carbon dioxide dissolved in water makes carbonic acid.

That's also why it's a good idea to run a refugium on a reverse light schedule, so the algae in the display works opposite the algae in the refugium.

[The Propagator]

Look at mr. smarty pants up there

 

[yardboy]

Mommy told me my pre-K education would help me out someday.

[The Propagator]

I learned how to make mud pies.

[Greenstar]

I learned how to make mud pies.