pH dropping during cycle

Yup, just keep monitoring it. If it continues to drop into the low 7's, that is another story. But you are just fine for now.

 

I already noticed that. It actually overflows like crazy. Mine is sitting in sump with lid off and drain plug open.

Is it ok to let it just overflow back into the sump skimmer chamber for now? I suspect it will quit doing so after few days.

Volute is open all the way at the moment. I think the only thing I can do to make it overflow less right now is raise it so it does not sit so deep in water.

 

It should only last a day or so. Easiest way is to raise the skimmer as you thought. Yes its fine to let it overflow, since it is really not pulling anything out yet.

 

No, don't try to chase it right now.

The range/swing you're seeing is normal, and will always be there to some degree even once the tank is established.

The only interesting thing I see in the history, is what kicks on at ~3PM? Fans or the A/C? Seems like there's a sudden increase of O2 right there.

 

I've added buffer.

 

Oh you must have added quite a bit to bring it up that much so quickly. In which case, you may have caused an Alk spike, depending on which product you were using. Not a problem in a cycling tank, but that would be a problem in an established tank with livestock. And if the buffer is Alk based, that also could cause a precipitation event; not something you want to experience (trust me).

 

I hear ya. Being first day of cycling I thought it would be ok. Def not gonna chase PH in general from now on.
I've also turned on the lights and set them on schedule, and turned on the skimmer. That should help keep PH in check.
Thanks everyone!