Join Date: Sep 2003
Location: Somerdale, New Jersey USA
Don't inject until you get a steady kH measurement of 3.0°H or 3.5°H. Otherwise you could have real problems with the pH.
As to the crushed coral; it will work well, but it is slow acting and you may not see a rise in kH for a week or two. Then you can adjust the amount of coral to suit your needs. I would go with .50 cup of it and test frequently for content. IME, it's not like you're going to wake up in the morning and find a kH of 12°H. As I said it takes time to act, especially in a 90. If you find that it's not reacting as quickly as you'd like, you can also use baking soda to raise kH. Be careful with this however. It will work much more quickly to raise kH.
Start your CO2 in the morning, on a day that you will be able to monitor the pH at least every 2 hours. Start with 1 bps, and wait 2 hrs. and test for content. Adjust your needle valve in very small increments to achieve 15 - 20ppm/CO2 at lights out. NO MORE!! The following morning test again at lights on to see how the tank has reacted over night. Be conservative with the gas until you know how it will affect your water table.
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