I apologize ahead of time for the long post, but I wanted to make sure I didn't miss anything.
I recently moved this past July into a bigger home. I have a 260g mixed reef with mostly LPS. Prior to the move, I was dosing about 200ml a day of Ca and sodium hydroxide (needed the pH boost) and alk was stable around 9. I moved in July and unfortunately had a tank crash due to reusing an unrinsed sand bed. A friend held onto my coral for a few weeks and I pulled the surviving fish. I left the tank dark for a few weeks while I went fallow and quarantined all my fish. When I got my coral back this past Sept, I also purchased about a dozen sps frags. I also restarted dosing trace elements and upgraded my lights to the Skys. I resumed dosing based on my old schedule. Alk was initially stable around 9 dKh. My coral were growing like crazy, but it turns out my new house has much less CO2 than my old house. With the sodium hydroxide, pH was climbing. I started hitting pH peaks of over 8.5, but I was needing more and more 2 part to maintain alkalinity. As a result, my salinity kept climbing. At that point, I switched to soda ash and also started doing 1.5g awc with RODI. Salinity stayed perfectly stable, the pH dropped to 8.2-8.3, but the alk requirements didn't. In a 260g system, I'm dosing about 1600ml/day of 2 part. I've been supplementing with sodium bicarbonate, but it doesn't seem to help lower my alk demand at all. As I started to reintroduce my fish, I realized that my sand bed was almost totally calcified. I tried to separate dosing alk and Ca, but my alk dropped 0.8dKh between 12am and 6am.
How do I get out of this cycle of precipitation without dropping my alkalinity so much?
I recently moved this past July into a bigger home. I have a 260g mixed reef with mostly LPS. Prior to the move, I was dosing about 200ml a day of Ca and sodium hydroxide (needed the pH boost) and alk was stable around 9. I moved in July and unfortunately had a tank crash due to reusing an unrinsed sand bed. A friend held onto my coral for a few weeks and I pulled the surviving fish. I left the tank dark for a few weeks while I went fallow and quarantined all my fish. When I got my coral back this past Sept, I also purchased about a dozen sps frags. I also restarted dosing trace elements and upgraded my lights to the Skys. I resumed dosing based on my old schedule. Alk was initially stable around 9 dKh. My coral were growing like crazy, but it turns out my new house has much less CO2 than my old house. With the sodium hydroxide, pH was climbing. I started hitting pH peaks of over 8.5, but I was needing more and more 2 part to maintain alkalinity. As a result, my salinity kept climbing. At that point, I switched to soda ash and also started doing 1.5g awc with RODI. Salinity stayed perfectly stable, the pH dropped to 8.2-8.3, but the alk requirements didn't. In a 260g system, I'm dosing about 1600ml/day of 2 part. I've been supplementing with sodium bicarbonate, but it doesn't seem to help lower my alk demand at all. As I started to reintroduce my fish, I realized that my sand bed was almost totally calcified. I tried to separate dosing alk and Ca, but my alk dropped 0.8dKh between 12am and 6am.
How do I get out of this cycle of precipitation without dropping my alkalinity so much?
