Effects of PH changes or swings

[roundar]

I was wondering if anyone had any articles or studies on the effects of drastic PH changes in the aquarium. I'm basically looking for some science to back up claims to better my understanding. I mostly ask because there are keepers/breeders who, in their (rather extensive) experience, suggest that PH changes of 1 or so, have no effect. I realize that the PH scale is logarithmic, so any changes over 2 I suspect can't be healthy ( since for example, a PH of 6 is 10x more acidic than a PH of 7, but 1000x more acidic than a PH of 9. ) I'm also familiar with PH changes effects in breeding, but any information on that is welcome as well.
Thanks!

 

[roundar]

Myths of pH Shock
http://www.oscarfish.com/article-home/water/74-realities-of-ph-shock.html

There seems to be some debate on the matter, but this is very informative. There doesn't seem to be any science behind PH shock, which is good to know.

 

[scottayy]

This is interesting. pH has baffled me since day 1. I've never bothered to read about it. However, since I have my fuge light on in my sump during the nighttime hours it seems to make the pH a little bit more stable. Or it could just be the results of an aging aquarium making it stable.

 

[bruinsbro1997]

That's interesting. However if you want to know about pH my knowledge of it is limited but I can give you some info.
pH is a huge factor, it can kill or flourish your fish. IMO having a stable pH is better than having an ever-changing one. The reason that breeders might reccomend that is that in the wild, breeding starts during the rainy season (ex. in the Amazon river) where pH changes rapidly due to fall of the rain. This often gets fish to know its time to breed. Breeders probably do this to replicate the natural conditions to try to get a higher chance of fish to breed. Some fish may also be able to tolerate being moved from different pH water because they were probably wild-caught and moved from different pH water all the time. Just my thoughts on the subject.

 

[severum mama]

IME it is not changes in pH that shock fish, but rather changes in GH, KH, TDS. pH is more or less a symptom of what is going on with those other values.

 

[mfdrookie516]

I agree with severum mama... pH can be changed by a lot of things that don't affect the chemical properties of the water like hardness, TDS, and all that other fun scientific stuff. My pH changes big time on a daily basis. At night, without co2 going, it goes up to 7.8 which is the normal pH for my water. During the day with the co2 cranking, it drops down to 7 or so. On another tank, the substrate drops the pH to 6.4... but I do 50% water changes weekly with tap water that tests at 7.8... nothing scientific there, other than using the word a time or two, but experience has to mean something, right?