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Unread 05/09/2011, 01:33 AM   #12
tmz
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Join Date: Apr 2006
Location: West Seneca NY
Posts: 27,691
I use fully saturated kalk for top off from a still reservoir dosed over a 24 hr time period. I tweak rarely with baking soda and anhydrous calcium chloride( some old Prestone driveway heat).

Two part is calcium chloride and carbonate alkalinity( baking soda/ soda ash).Some commercial products contain some magnesium as well.Balanced dosing entails 20ppm calcium for 50ppm carbonate/bicarbonate which is the ratio used when calcium carbonate is made by calcifying organisms. You can dose them independently to tweak one or the other but it is generally best to maintain balanced dosing. You can also dose more alk at one time than you can with kalk which raises ph. You are adding extra chloride but not enough to worry about particularly when water changes are done regularly or when magnesium sulfate supplements are used.

Kalk is one part ( calcium hydroxide). The calcium breaks away when it hits the water and the oxide binds with CO2 and some H+ along the way creating carbonate( CO3) and bicarbonate(HCO3). Calcifying organisms then take up the bicarbonate and calcium and join them to form calcium carbonate as skeletal mass. As the OH(oxide) reduces CO2 and adds CO3 it raises ph. Fully saturated kalk water has a ph of about 12.4 The amount you can dose at one time is limited to avoid ph spikes and consequent precipitation. It's best to spread it out as top off over a long time period ( not less than 5 hours ) as possible. It is easy to use consistently from a still reservoir, with a dosing pump or drip device, inexpensive, self purifying and may precipitate some PO4 as an added bonus.


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Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.
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