Alk drop

[Albz]

question anout alk. Yestersay my Alk was around 9, and after 24 hours i tested again with red sea test kit and it dropped to 7.5...thats a pretty big drop off.. what can cause this?? I got lps and like 4 sps corals.. calcium is at 400, phos at 0.03.. i have a 29 biocube... right now i got no live stock, they all in my qt for a week..

 

[CodyRVA]

If you don't supplement it with either water changes or dosing it's going to fall naturally; how much all depends on your demand. Young tanks going through that "coralline" explosion will use up a lot of calcium and see ALK swings if not monitored. Same can happen with seasoned tanks with large coral colonies. So, either beef up your water change schedule & volume, use more "potent" salt, or dose. Considering it dropped that much, I would dose, but thats just my two cents. Cheers!