There is absolutely no advantage to keeping calcium anything over 420. Higher calcium doesn't make corals grow faster so if your at 450 no worries there. If you use a salt that is high in ca
to begin with you may only need to dose alk
. You can simply use Arm&Hammer baking soda. I've been using it for years.
This article may seem a little complicated, but it's really not.
An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
Basically you want to use Recipe 1 for alk
. Bake 2 1/4 cups of Arm&Hammer baking soda in the oven at 350 for 1 hr. Get a 1 gal
milk jug, fill it about 3/4 of the way with RO
water and add the baking soda. After it's added, top off the jug with RO
water. You now have 1 gal
The only way to know how much you will need to add is test today, test tomorrow, the day after, and the day after again. See how much your alk
drops each day, or every 2 days, etc. If it drops 1 dKH
every 2 days you can dose the equivalent of .5 dKH
every day....if you want to dose every day. How ever often you decide to dose you should never raise it more than 1 dKH
Use this calculator ('Reef Chemistry Calculator FV'
) to figure out how much you need to dose. Enter your total water volume, your current dKH
and what you want it to be, then for the supplement pick Randy's Recipe 1.
For example, if you have 125g total water volume, your alk
is 6 and you want it to be 7, you need to dose 3 fl oz of supplement.
And don't foget about mag. If your corals are using ca
, they are also using mag.