Originally Posted by
locoyo386
http:///forum/post/3074882
Hi there,
Can you explain "tends to correlate". If I understand your point correctly, pH level depends on specific gravity and viseversa. A low spefic gravity indicates a low pH and a high specific gravity indicates a high pH level. I still do not understand the corrolation. If pH depends on spefic gravity than a low pH would not be possible when you have a high specific gravity (1.025), is this correct? If you pH level drops from 8.4 to say 7.2, than your specific gravity will drop from 1.025 to something lower, is this correct?
Sorry for the tardy response, was out of town for the holidays.
Specific gravity is a function of the salinity of the water. Salinity is the function of the amount of salt dissolved in the water.
Salt has alkaline buffering capabilities. What that basically means is that the more salt present, the more able the system is to reach a more alkaline state, and a higher pH.
Therefore, as salinity increases, buffering increases, and pH should increase.
The should is there, because other chemical compounds can reduce the pH, by reacting with the buffer. This is why pH and alkalinity don't go hand-in-hand. Alkalinity tends to trend more long-term, while pH can change hourly, as it is dependent on many more factors.
So when you get your alk test in and test your tank, one of two things will happen:
1. Alkalinity normal. In this case, your pH is low probably due to dissolved organics.
2. Alkalinity low. This would explain your low pH. The problem is, what explains your low alk. Could be your sg reading is off, could be you have a bad mix of salt.
Once you can test alk, this will be easier to diagnose.
