Originally posted by neoreef
How can you then say not to add buffer to stabilize pH? That is what buffers do.
Or are you suggesting that one measure alkalinity and get that adjusted with buffer, instead of just adding buffer without measuring alkalinity? I can agree to that. One should not add buffer to "fix" the pH without knowing if the alkalinity is low, and how low it is.
If that is what you meant, great.
I'm sure Bang can explain better than I can, however, what I am trying to say is if your pH is low, then you shouldn't add a buffer to try to fix it without knowing what the alkalinity is also, as well as the calcium. you should not just target the ph with buffer, instead, find out what the alkalinity is and target that if it is indeed the problem.
The normal trend for pH in a tank is downward, or more acidic. The additions of acids into a tank will lower the pH in the tank water. These acids come from several sources, the primary ones being: (1) excess carbon dioxide (CO2) from respiration caused by lack of sufficient gas exchange, (2) nitric acid from biological filtration (nitrification), and (3) organic acids from metabolic wastes. Respiration and metabolic wastes are a natural part of the ocean. The reason that sea water pH does not change is that sea water contains a number of chemicals, such as bicarbonate, calcium, carbonate, borate and hydroxide, which act as natural "buffers" that retard the drop in pH.
Also important to note is the degree to which a solution maintains its pH when acid is added is termed the "alkalinity" of the solution. Ah alkalinity thats what you need to target. If you find that the alk is not the problem then you need to look at the other things like the gas exchange or the acids from heavy DOC's that might be causing problems.
Whew, I know I'm sometimes hard to follow, and my posts are not as elloquent or well thought out like NMR or BGuy but I hope that helps say what I'm trying to communicate.
Thomas
