pH difference

[deedubz]

Ok, long story short..
Did ttm/hypo for flukes and ich. Turned out to be velvet. 2 qt tanks, one has been in therapeutic copper 15 days while the other is at day 10. Quarantine 2(day 10) has two wrasses so, after talking to @Humblefish , I decided I'm going to transfer to a clean tank today with no copper or prazipro so I can do final dose of prazi(in 5 days) and start food soaking metro.

Actual question..
I ran out of my fritz rpm salt a few days ago and, given this coppersafe nonsense, I decided to switch back to red sea. My problem.. pH with fritz was consistently 7.8, while the new red sea qt mixed in at 8.4. 2pm will be 24 hours prazipro exposure (2nd of 3 planned doses) and I'm starting to get a bacterial bloom. I really want to get these fish out of this tank but the pH difference concerns me.
Salinity and temp match perfectly.

@Humblefish @Big G @Randy Holmes-Farley @4FordFamily Any thoughts?

 

[deedubz]

After retesting it looks like it could be closer to 8.1-8.2 rather than 8.4, though I'm still unsure. I have a hard time with these color tests. The occupied qt is definitely 7.8 though.

 

[Randy Holmes-Farley Verified Community Expert]

The pH is not really an attribute of a salt mix, at least after aeration. pH is determined only by by the alkalinity and the CO2 level in the air aerating the water (assuming it is fully aerated). If the alk matched, the pH will come to the same value. That's probably why the 8.4 is dropping to 8.1-8.2.

I also do not think a sudden pH change is an issue. Fish coming out of shipping bags get a big pH hit and do fine.

 

[deedubz]

Took a third test and still hate these stupid color charts. It's either 8.1 or 8.3.. I cannot tell. So, would a .3-.5 increase in pH harm these fish?

I read Randy's publication on pH but did not see anything mentioned about an imediate increase or decrease, just that most fluctuate throughout the day

 

[deedubz]

The pH is not really an attribute of a salt mix, at least after aeration. pH is determined only by by the alkalinity and the CO2 level in the air aerating the water (assuming it is fully aerated). If the alk matched, the pH will come to the same value. That's probably why the 8.4 is dropping to 8.1-8.2.

I also do not think a sudden pH change is an issue. Fish coming out of shipping bags get a big pH hit and do fine.

Right as I was updating thread. Thank you for your advice. I also added a couple air stones, after reading your article, to see if that'd help drop it a little lower. The transfer is about an hour away and I was starting to get a little nervous. Thank you again!