Ph swing?

[Haddonisreef]

My ph swing at night 330 am 7.75 low and @ 10pm sit at like 8.10 Seems like a big swing is this safe? Everthing seem happy, ph read by Reef Keeper 2 Thanks C

[sabazerehi]

that's not too bad of a swing and it's normal for ph to drop at night, not as much photosynthesis is going on so not as much oxygen in the tank, hence the ph drop.

[joeychitwood]

Here (http://www.reefkeeping.com/issues/2004-09/rhf/index.php) is a great article on reef pH including a discussion on diurnal variations.

[crvz]

seems pretty standard, I wouldnt be worried about it.

[Haddonisreef]

Thanks im going to add more cheto to see if i can raise it>

[Rouselb]

Its normal for that kind of change. If you want to stabilize it more, you can do two things, first you can add macro and leave the lights on a reverse cycle to your main tank, the second is you can dose Kalk when the lights are off.