How much do you swing?
 

PH wise:biggrin: Im just wondering what a normal swing in ph is in the average tank? Now that I can easily see what my PH is at any given time with the ACJR I am alarmed at how much of a swing I am getting. 7.8 in the AM and 8.3 in the evening. Is this to big of a swing?

The best ones to answer this are your tank inhabitants. Are they fine, or are they looking stressed? Personally, I think pH was invented by retailers wanting to sell things to firstly measure it, then sell you stuff to stabilize it :)
Just don't have your pH display somehwere the fish can read it, and I'm sure you'll be fine.

:lol: I have to say I agree. I haven't had a problem with ph since I quit checking it over 2yrs ago

I think sudden swings in pH is what you really need to be concerned about. i.e. calcium reactor pumping excess CO2, or big dump of Kalk. Otherwise your slow pH change over the course of a day is fine. The amount of your "swing" may suggest a reduced buffering capacity of the water. You may want to have a look at your alkalinity just to be sure.

7.8 to 8.3 is 100% normal.

But +1 to all the comments. pH of tank water in reef tanks is nearly useless to track. It's a resultant value of other more meaningful numbers.

Useful to track in a calcium reactor though, since you want to add enough CO2 to drop the pH in the chambers to 6.7.

Couldn't tell you because I haven't checked it in a long time. I realized my pH is going to do what it wants and nothing I do is going to have any real impact.

Mine swings between 8.0-8.3... posted the same question on RC and got a reply that mine was normal...

This was posted by a member there...

I agree. I don't test pH either.

I don't test pH on my 90 gal, but the 225g has the AC Jr. controller. (swing of 7.9 to 8.3). Since I put the refugium on a reverse photo period the pH only differs by .2

You can test this?