Wow it seems everything I was doing was wrong. I was buffering my water with Kent Marine pH buffer every 2 weeks. I eventually quit doing it because I noticed no change in pH ever, even well after I stopped buffering.
So many questions now. Please expound upon your statement about pH buffer is a mistake. If what you say is true why do they make the product.
I have been reading a lot about calcium and that has triggered questions
1. Is there a calcium test that is required and how often?
2. how do you maintain calcium outside of what comes from the RO water?
3. what is the relationship between calcium and pH?
4. How do you maintain proper pH levels.
thank you for the answers I want to nail all this down and learn before I start up a new tank unprepared.
They make the product because a lot of people buy it. It is useful to raise Alkalinity so it is a valid product but should only be used to maintain or raise Alkalinity.
1 - yes most brands have a calcium kit. I prefer Salifert but most brands are fine. I would test once a week, more often if you notice issues.
2 - there should be no calcium in RO water. To maintain calcium the first step is to test it and chart the results over time so you get an idea of the consumption level. For many tanks just water changes are all that's required. For systems that consume it faster there are many good calcium additives on the market, or limewater, or a calcium reactor. If your consumption is low I would first suggest just doing a water change when it gets low. If that's insufficient the next step would be a two part additive like B-Ionic.
3 - there is a loose relationship between Calcium and PH, it's very indirect and too complicated for a short answer. PH is more closely associated with Alkalinity but that's fairly indirect as well.
4 - If Alkalinity is in a good range and PH is low then it is almost always excess Carbon dioxide in the water. The second cause could be from metabolic acids in the water from rotting organic matter. Determine the cause (or causes) and then make a plan to fix the actual problem.