PH ups and downs

[wallysworld]

Now that I have a ph monitor I see a 0.30 change from morning to evening. In the morning the ph is 7.98 however in the evening I can see its around 8.2. Is this ok for corals?
I started changing when I add my 2 part B-IONIC to the a.m. when I can see the ph is low. I notice it will bring the ph up about .15 to .20 after about 10 minutes. I used to add the 2 part in the evening which I am think was the worse thing I could have been doing.
Is the a better way to control the ph? Is it possible to keep it at a constant?
I plan on doing a water change this weekend. Last change was 3 weeks ago (10%). Don't feed too much IMO.
Any help is much appreciated.

Thanks,
Walter

 

[Josh]

That is perfectly normal. Your PH will go up until your lights go off each night.

If you have a refugium, you can set the photoperiod of the refugium lighting to go on when your tank lights go off and that will smooth out a small bit of the PH swings.

 

[wallysworld]

Josh,

Good to hear. What would you concider too much of a swing?

Thanks,
Walter

 

[KathyC]

As Josh mentions, that sort of swing is perfectly normal. You don't want to/need to do anything to try and stabilize it at a specific level.

What time of the evening are you taking the reading, are the lights still on then?

 

[Josh]

I'm not sure, but I occasionally see swings of more than .5 during the day and if you are at .3 you are doing fine.

 

[wallysworld]

Josh, ok that sounds good. I am interested to see if a water change cuts down on the swing? Would be cool if I could use the swing as a guage for water changes.

Kathy, Yes the lights are still on until about 9:00pm. 4-T5's on for 7 hours and 2 - VHOs on for 9.

Thanks,
Walter

 

[KathyC]

More frequent water changes might lessen it but not by much. Frankly I wouldn't worry much about it as it is a small swing and it happens gradually over a fair number of hours. The PH swings that cause damage are sudden ones.
Frequent water changes are always more beneficial to your tank as the quality of the water doesn't have much time to deteriorate, and with each change you are adding the essential minerals and elements back to the tank by doing them.
I would not wait for the PH to change as a guide to changing the water - that is too late

 

[wallysworld]

right I will stick to water change every 3 weeks. Now I am hooked on having a monitor for all my parameters! So much easier then using those test kits!

Thanks!

 

[SnakeEyes27]

This may be a natural result of photosynthesis. I wonder if there are reef safe buffer solutions to keep this in check.

 

[KathyC]

This may be a natural result of photosynthesis. I wonder if there are reef safe buffer solutions to keep this in check.

It isn't really something you want to or need to keep in check as it is normal. While there are buffers out there that can stabilize your PH many can mess with your alk levels, and that is not a good thing. Products like PH Up and PH Down only offer very temporary changes and those can be terribly hard (and deadly) to fish is not used correctly.
PH is something you want to alter as little as possible with the expection of what naturally occurs during light to dark cycles...which is what Wally's tank is experiencing

 

[Josh]

Like Kathy said, you shouldn't be worried about that swing.

Also, it should have no impact on your water change schedule unless it stays up or down for more than a day. That would indicate some sort of problem with the tank (most likely a gas exchange problem due to a pump failing or something).

 

[mckostya]

my ph goes down to 8.0 at night and stays 8.4 in the day. is that too much of swing? everything is growing and happy

 

[Chris Jury]

As long as the pH isn't dropping below ~7.8 or rising above ~8.5 I wouldn't worry too much. pH variation of ~8.0 to 8.2 isn't something I'd worry about at all. Especially with higher than NSW alkalinity, most organisms and processes (that we care about in captivity) are going to be just fine.